Evidence on treatment practice, discharge outcomes, and associated factors in patients with psychiatric disorders are rarely discussed in Ethiopia. Results from the available studies are also seldom consistent and miss important factors, including treatment-related variables. Therefore, this study intended to describe management practice and discharge outcome among adult psychiatric patients admitted to psychiatry wards of selected specialized settings in Ethiopia. By pointing out associated factors, this study will also provide insight on targets to improve discharge outcomes.p value < 0.05 was used to declare statistical significance.A cross-sectional study was conducted involving 278 adult psychiatry patients admitted to the psychiatry wards of Jimma Medical Center and St. Amanuel Mental Specialized Hospital in the study period from December 2021 to June 2022. The data was analyzed using STATA V.16. Descriptive statistics and logistic regression analysis were performed to present patient characteristics and identify factors associated with discharge outcome, respectively. In all the analysis, P = 0.021) than non-chewers.Schizophrenia  and bipolar disorders  were the top two psychiatric disorders diagnosed at admission. A greater share of patients with schizophrenia were treated with the combination of diazepam, haloperidol, and risperidone than with diazepam and risperidone, 14 (5.04%) each. Patients with bipolar disorder were being treated primarily with the combination of diazepam, risperidone, and sodium valproate, or risperidone and sodium valproate, 14 (5.04%) each. Overall, 232 (83.4%) patients were on psychiatric polypharmacy. In this study, 29 (10.43%) patients were discharged unimproved, and this risk was significantly higher in those patients with a khat chewing habit (AOR = 3.59, 95% CI = 1.21–10.65, Psychiatric polypharmacy was found to be a common treatment approach in patients with psychiatric disorders. In the study, a little more than one-tenth of patients with psychiatric disorders were discharged without improvement. Hence, interventions targeting risk factors, especially khat use, should be undertaken to improve discharge outcomes in this population.The online version contains supplementary material available at 10.1186/s12888-023-04860-3. Mental disorders are syndromes characterized by clinically significant disturbances in an individual’s cognition, emotional regulation, or behavior. These disturbances are associated with dysfunctions in the psychological, biological, or developmental processes , leadingGlobally, in 2016, more than one billion people were affected by mental or addictive disorders, accounting for approximately 16% of the global population. While the global data in 2017 shows an estimated 264 million, 45 million, and 20 million people were living with depression, bipolar disorder, and schizophrenia, respectively .Depending on their presentations, patients with psychiatric disorders can be treated either in an outpatient or inpatient setting. Inpatient treatment is chosen particularly when the patient behaves disorganized, exhibits psychotic features, or cannot be safely managed as an outpatient . The treThe quality of mental health services varies across the globe. For instance, the existing mental health services in low-income countries have been characterized as inadequate, inequitable, and inefficient. In developing nations, particularly in Sub-Saharan Africa, the lack of infrastructure and the limited number of psychiatric beds per population remain a significant barrier to improving mental health services in the region –14. ThisIn general, there are only limited studies on the discharge outcomes of patients with psychiatric disorders. According to the available research, a high proportion of discharges results in a better outcome , 16. ForIn Ethiopia, evidence on treatment practices, outcomes, and associated factors in patients with psychiatric disorders is rarely discussed in the literature. Results from the available studies are also seldom consistent. The existing studies reported discharge with improvement of 90.3%  and 74.9The study was conducted from December 1, 2021, to June 30, 2022, at the Psychiatry Ward of Jimma Medical Center (PWJMC) and St. Amanuel Mental Specialized Hospital (SAMSH). SAMSH is the largest mental specialized hospital in Ethiopia, providing mental health services to clients from all over the country. It is located in Addis Ababa, the capital of Ethiopia. At the outpatient level, it serves more than 800 patients daily. It has a capacity of 270 beds for inpatient care. The number of emergency visits per month is close to 2000 , 19. On A cross-sectional study was conducted involving adult psychiatry patients admitted to PWJMC and SAMSH.All adult psychiatry patients admitted to PWJMC and SAMSH.All adult psychiatry patients admitted to PWJMC and SAMSH who fulfilled the inclusion criteria during the study period.All psychiatric patients age ≥ 18 years who were admitted to PWJMC and SAMSH during the study period.Those who were refused to participate.Patients who stayed in hospital beyond the study period.Patients who were unable to communicate.The sample size for patients’ discharge outcome was calculated using a single population proportion formula. A 50% proportion (P) was considered for patients’ unimproved discharge outcome. Considering a 0.05 margin of error (d) and 95% confidence interval, n = the required sample size.1-p = q = 0.5d = Expected margin of error = 0.05Z α/2 = 95%confidence interval (C.I) = 1.962 = 384Thus, n = ((1.96)2 × 0.5x 0.5)/ (0.05)Since the target population was less than 10,000, the sample size should be corrected using the following correction formula.Where nf is the corrected sample size and N is the number of patients admitted in the two hospitals in the last years’ seven month period of similar season, which was 833.Thus, nf = 384/1 + 384/833 = 264.After accounting for a 5% non-response (14 patients), the final sample size was 278 patientsBased on previous admission data, this number was proportionally divided in the ratio of 1:5 for both hospitals. Accordingly, 47 and 231 patients were allocated for PWJMC and SAMSH, respectively.A consecutive sampling technique was used to recruit the study participants.Data was collected through patient interviews and a review of medical records using a questionnaire developed after reviewing relevant literature , 15–17. The Life Events Questionnaire (LEQ) was used to assess recent life events. It is a 12-item self-rating instrument that assesses common life events that are potentially threatening. Respondents were asked to select life events that had occurred within the past 12 months prior to the onset of their psychiatric symptoms. Each life event was answered dichotomously (yes or no) and was scored 1 if it was ‘yes’ and 0 if it was "no." A total score was the sum of all items .The Oslo Social Support Scale (OSSS-3) was used to assess perceived psychosocial support. The OSSS-3 consists of three items that assess the level of social support. The sum score ranges from 3 to 14, with high values representing strong levels of social support and low values representing poor levels of social support, which was interpreted as [3-8] is poor social support, [9-11] is moderate social support, and [12-14] is strong social support .The adherence assessment tool, the Medication Adherence Rating Scale (MARS-5), was used to assess adherence. MARS-5 is a 5-item self-report scale that is used to detect non-adherent behavior by self-report. It is a measure of non-adherence in general, not for mental disorders in particular. The questions are formulated in a non-threatening and non-judgmental way to minimize social desirability bias. The item responses are scored on a 5-point Likert scale, where 1 = always, 2 = often, 3 = sometimes, 4 = rarely, and 5 = never. Scores range from 5 to 25, with higher scores indicating higher adherence. Psychiatric patients who scored 23 or above were classified as adherent to their psychotropic medication, while those who scored less than 23 were classified as non-adherent .The Mental Health Trigger Tool (MHTT) was used for efficient chart review and identification of adverse drug reactions (ADR) in addition to self-reported ADR by patients themselves. The MHTT was developed with the aim of detecting and measuring both traditionally defined ADRs and other patient safety incidents relevant to mental health settings. It is an easy-to-use tool for understanding and measuring a variety of patient safety incidents in mental health settings and it is designed for use in inpatient mental health settings. The tool contains a list of 25-item triggers related to general care, laboratory, medication-related, and behavior-related items [The clinical global impression (CGI) scale was used to assess the outcome at discharge. The CGI is an overall clinician-determined summary measure that considers all available information, including knowledge of the patient’s history, psychosocial circumstances, symptoms, behavior, and the impact of the symptoms on the patient’s ability to function. It has two components: the CGI-Severity (CGI-S), which rates illness severity, and the CGI-Improvement (CGI-I), which rates change from the initiation (baseline) of treatment. The CGI-S asks the clinician one question: "Considering your total clinical experience with this particular population, how mentally ill is the patient at this time?" which is rated on the following seven-point scale: 1 = normal, not at all ill; 2 = borderline mentally ill; 3 = mildly ill; 4 = moderately ill; 5 = markedly ill; 6 = severely ill; 7 = among the most extremely ill patients. The CGI-I is similarly simple in its format. Each time the patient is seen after treatment has been initiated, the clinician compares the patient’s overall clinical condition to the one-week period just prior to the initiation of treatment (during admission). The CGI-S score obtained at the baseline visit serves as the basis for this assessment. Again, only the following query is rated on a seven-point scale: "Compared to the patient’s condition at admission, this patient’s condition is: 1 = very much improved since the initiation of treatment; 2 = much improved; 3 = minimally improved; 4 = no change from baseline; 5 = minimally worse; 6 = much worse; 7 = very much worse since the initiation of treatment." There are no universally accepted scoring guidelines for the seven anchor points; rather, they were designed to be based solely on clinical judgment. The CGI is applicable across all CNS studies, including depression, schizophrenia, bipolar disorder, and anxiety, no matter the population, drug, or other main study measures. It provides a readily recognizable and universally known efficacy measure that distinguishes it from the more complex, lengthier, and sometimes difficult to administer efficacy scales .Three data collectors were trained on the research tool and data collection procedure. All patients included in the study were followed from the first day in the psychiatry ward until the date of discharge using a follow-up chart included in the questionnaire.The questionnaire was carefully tailored to collect all of the necessary information, and it was translated from English to Afan Oromo and Amharic and then back translated into English. A pretest was conducted on 5% of the study participants from JMC. Three trained psychiatry nurses and clinical pharmacists collected the data. After data was collected, before being exported to STATA V.16 for analysis, the data was cleared, categorized, compiled, coded, and also checked for completeness and accuracy.p-value < 0.25 in bivariate regression were considered suitable for multivariate logistic regression. Then, multivariate logistic regression was employed to identify independent predictors of an unimproved discharge outcome. The odds ratio was used as a measure of the strength of association and p-value < 0.05 was considered to declare statistical significance. The Hosmer and Lemeshow test (p > 0.05) was performed, indicating good fit.Epidata V. 4.2.0 was utilized for data entry, and the data was exported to STATA V.16 for analysis. Continuous variables were summarized using the mean ± standard deviation (SD), while categorical data were reported as frequencies and percentages. A chi-square test was performed to check the adequacy of cells before conducting regression. To examine multicollinearity, the variance inflation factor (VIF) was assessed, and independent variables with a VIF < 6 were included in the model. For the discharge outcome, bivariate logistic regression was used to identify candidate variables for multivariate logistic regression. Variables with a Condition of the patient at discharge compared to the patient’s condition at admission. Based on the CGI score and for the convenience of this study the patient’s discharge outcome was classified as ‘currently improved’ if the patient’s condition at discharge was very much improved; much improved or minimally improved since admission. Similarly, the patient’s discharge outcome was classified as ‘currently not improved’ if the patient’s condition at discharge was no change from baseline; minimally worse; much worse; very much worse since the admission, left against medical advice, died, referred or absconded .A medical condition in a patient that causes, is caused by, or is otherwise related to another condition in the same patient .The prescription of two or more psychotropic medications concurrently to a patient .Use of substance(s) on a consistent and habitual basis for a period of more than one month . SubstanA maladaptive pattern of substance use leading to clinically significant impairment or distress as manifested by one (or more) of the following occurring within a 12-month period: recurrent substance use resulting in a failure to fulfill major role obligations at work, school, or home, recurrent substance use in situations in which it is physically hazardous, recurrent substance-related legal problems, and continued substance use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance ..Among the 292 admitted psychiatric patients screened during the study period, 278 patients fulfilled the inclusion criteria. Fourteen patients were excluded from enrolment for not meeting inclusion criteria, with a response rate of 95.2% Fig. .Fig. 1St(Table 1).Among the 278 patients enrolled, 165 (59.35%) were male, and the mean ± standard deviation of the age of the patients was 32.3 ± 9.7 years. Self-reported substance use was noted in 113 (40.65%) of the study participants. More than one third, 106 (38.13%) of the patients, had family history of psychiatric  illnesses. With regard to social support, 172 (61.87%) and 47 (16.91%) of the patients reported moderate and poor social support, respectively (Table 2).Clinically, the majority of the study participants were known psychiatric patients: 204 (73.38%). More than half of the enrolled participants had previous history of hospitalization, 151 (54.32%). More than a quarter, 74 (26.62%) of patients, had a suicide risk at admission. The mean ± standard deviation of the hospital length of stay of the patients was 40.9 ± 20.7 days Schizophrenia, 125 (44.96%), and bipolar disorders, 98 (35.25%), were the top two admission diagnoses followed by acute and transient psychotic disorder, 54 (19.42%), major depressive disorder, 32 (11.51%) and Substance use disorders, 30 (10.79) respectively  of the patients received at least one psychotropic medication during their hospital stay and at discharge. Among the conventional antipsychotics, haloperidol was the most widely used drug, 65 (23.38%). More than two thirds, 192 (69.06%) of the study participants were prescribed risperidone. Sodium valproate was the most commonly used, 79 (28.42%), drug among the mood stabilizers. Fluoxetine took a greater share of prescriptions, 21 (7.55%), among anti-depressants. Nearly half of the patients enrolled, 123 (44.24%), received diazepam. Trihexyphenidyl, 34 (12.23%), was the most commonly used non-psychotropic medication.Psychiatric polypharmacy was observed in a greater proportion, 232 (83.45%), of study participants. Nearly three-quarters of the patients, 205 (73.74%), had psychotropic drug use history. More than half of the study participants, 144 (51.8%) were non-adherent towards their medications. Electroconvulsive therapy was instituted in only 20 (7.19%) patients  each. Bipolar patients were being treated mainly with the combination of either diazepam, risperidone, and sodium valproate or risperidone and sodium valproate, 14 (5.04%) each. The combination of fluoxetine and risperidone, 8 (2.88%) were the most commonly used drugs among major depressive disorder patients. Among patients with substance use disorder diazepam and risperidone, 6 (2.16%) were the most widely used drug combinations  were discharged without improvement Table .Table 5Dp = 0.033) and rural residence (P = 0.041)  Table . Whereas1) Table .Table 6Cp = 0.019) and the length of psychotropic treatment before admission (p = 0.025). However, after adjusting for variables with a p-value < 0.25, multivariate logistic regression analysis identified being a khat user as the only independent predictor of an unimproved discharge outcome. Accordingly, khat users were about 3.6 times more likely to be discharged without improvement than patients who were non khat users   Table .Table 8CThis cross-sectional study assessed the management practice and discharge outcome of psychiatric patients admitted to psychiatry wards of selected hospitals in Ethiopia. Accordingly, in terms of pharmacotherapy, psychiatric polypharmacy was observed in a greater proportion, 232 (83.45%), of the study participants. This may be partly attributed to the patient’s presentation with an acute exacerbation of symptoms and, in some cases, a long-standing disease with different psychotropic medication trials. There are several reports indicating a high prevalence of psychiatric polypharmacy in recent clinical practice. Despite widespread use, there is relatively little evidence that this strategy is helpful, particularly when clozapine is not involved . In patiRegarding outcomes on discharge, the present study demonstrated high rates of improvement in symptoms of patients upon discharge (89.57%). The relatively longer hospital stay (40.9 ± 20.7 days) and clinician-observed medical therapy might have contributed to the higher rate of improvement in symptoms upon discharge. However, participants discharged without improvement should not be overlooked because this group of patients is at higher risk of early readmission and subsequent progression of a chronic condition. This finding is similar to studies from Ethiopia (90.3%)  and NepaIn this study, Khat users were about 3.6 times more likely to be discharged without improvement than patients who were non khat users. The possible explanation for this could be the increase in psychiatric symptoms among khat users during their admission and hospital stay. In one large meta-analysis , khat usThe sample size used was relatively small compared to retrospective studies conducted using registries due to the short study period and resource constraints. Moreover, our study was not able to detect the effect of the specific past psychotropic medications the patients were taking, and we were dependent only on the general presence or absence of past psychotropic medication use history. Furthermore, the trigger tool used to detect adverse drug reactions was taken from an article and was not validated in Ethiopia.Psychiatry polypharmacy is a common treatment approach in patients with psychiatric disorders. The second-generation antipsychotics, especially risperidone, were commonly used for the treatment of psychiatric disorders along with other medications as combination therapy. Higher rates of improvement in symptoms were observed upon discharge. However, participants discharged without improvement should not be overlooked. Hence, interventions targeting risk factors, especially khat use, should be undertaken to improve their discharge outcome.Additional file 1: Supplementary Table 1. Dataset of the study ’Management practice and discharge outcome of patients with psychiatric disorder admitted to psychiatry wards of selected specialized settings in Ethiopia'.


Healthcare providers frequently help traumatized people and are regularly exposed to indirect trauma from their work, resulting in negative psychological responses, such as secondary traumatic stress. Empathy has been associated with patient’s quality of care and secondary traumatic stress among healthcare providers. However, the relationship between dispositional empathy and secondary traumatic stress has not been fully elucidated. This study used person- and variable-centered approaches to explore the nature of this relationship.A total of 1,006 Japanese public health nurses working in the Tohoku region and Saitama prefecture completed questionnaires that included scales assessing dispositional empathy, secondary traumatic stress, and burnout. First, we examined predictors of secondary traumatic stress using multiple linear regression analysis. Then, we conducted a latent profile analysis to classify participants into unique groups based on four subscales of dispositional empathy  and secondary traumatic stress. Finally, we compared the mean values of the study variables across these groups.The multiple regression indicated that in those working in Saitama prefecture, lifetime traumatic experiences, work-related distress, and personal distress were positively related to secondary traumatic stress, but perceived support was negatively related to secondary traumatic stress. Latent profile analysis extracted four unique subgroups. Group 1 displayed the highest secondary traumatic stress levels. Group 2 was characterized by the highest level of empathic concern, personal distress, and fantasy and the lowest perspective taking. Group 3 had a moderate secondary traumatic stress level. Group 4 had the lowest secondary traumatic stress and personal distress scores. In these four groups, the burnout scale  showed a pattern similar to the secondary traumatic stress scale.Our person-centered approach showed that this sample of public health nurses could be classified into four unique groups based on their empathy and secondary traumatic stress scores. Although this group of public health nurses was not large, one group displayed high personal distress levels and high secondary traumatic stress levels. Further research is needed to determine effective interventions for this group.The online version contains supplementary material available at 10.1186/s12888-023-05198-6. Healthcare professionals are frequently exposed to indirect trauma by constantly assisting those traumatized, which may have adverse psychological effects including secondary traumatic stress (STS) . STS refResearchers and healthcare providers have viewed empathy as a characteristic of healthcare providers associated with patient care quality. Empathy is the capacity to identify and understand others’ responses to their experiences when they are observed and is a core characteristic of social animals, including humans , 9. It hThe multidimensional model of empathy has posited that dispositional empathy comprises both emotional and cognitive components , 10, witPhysicians’ expressions of empathy are associated with increased patient satisfaction, trust, autonomy support, and knowledge . MoreoveHowever, dispositional empathy has also been related to STS . A studyImmediately after the Great East Japan Earthquake in 2011, public health nurses were ones of front-line workers who potentially experienced extreme distress by helping others. During the aftermath of the earthquake, the roles of public health nurses included visiting shelters for health and hygiene management for the evacuees, visiting homes of people who needed support, and supporting the restart of health services . As theyAlthough a person-centered approach is used less frequently than a variable-centered approach, its popularity has increased . Such ann = 2,085) working in the Tohoku region of Japan , where the 2011 Great East Japan Earthquake occurred, were recruited as potential participants. We also recruited 1,019 public health nurses working in Saitama prefecture, a neighboring prefecture of Tokyo. Of these 3,104 potential participants, we received 1,259 survey packets, representing a 40.6% return rate.Public health nurses  public health nurses. A flow chart of participant recruitment and inclusion is shown in Fig. In the Tohoku sample, 889 public health nurses returned their survey. Among them, 99 did not fill out any of the items of the Interpersonal Reactivity Index-Japanese version (IRI-J), Secondary Traumatic Stress Scale-Japanese version (STSS-J), or Maslach Burnout Inventory-Japanese version (MBI-J), resulting in 790 valid responses from participants. In the Saitama sample, 370 public health nurses returned the survey; however, 19 did not complete any items on the IRI-J, STSS-J, or MBI-J, resulting in 351 valid responses. As we investigated the effect of indirect trauma exposure through interaction with clients, 96 and 58 responding public health nurses, who lacked direct interaction with clients as a part of their job were excluded from the Tohoku and Saitama samples, respectively. The final sample included 1,006  to 5 (describes me very well). The fantasy subscale measures the tendency to be deeply involved in, and associate their feelings with, fictitious characters in movies, books, or plays [Dispositional empathy was measured using the IRI-J . The 28-or plays , such asSecondary traumatic stressnever) to 5 (very often). Sample items included “I felt emotionally numb,” “I wanted to avoid working with some clients,” and “I was easily annoyed.” The internal consistency coefficient for the present study was 0.94. The STSS-J is available upon request.STS was assessed using the STSS-J . The oriBurnoutnever) to 7 . Exhaustion refers to the feeling of overextending and depleting one’s emotional and physical resources. Cynicism refers to negative, callous, or excessively detached responses to various aspects of a job. Professional efficacy refers to feelings of competence, achievement, and productivity at work [Burnout was assessed using the MBI-J , 25. The at work . Sample Perceived supportyes/no response format. The internal consistency coefficient for these items was 0.53.We collected data on perceived support for work-related issues using two items designed for this study. These items included “Do you have someone  who can talk or provide advice on work-related issues” for instrumental support and “Do you have someone  who supports or understands your attitudes toward work-related matters” for emotional support. Items were answered using a binary Work-related distressI didn’t feel it at all) to 5 (I felt very strongly). Respondents answer the items with the stem, “To what extent do you feel stressed about the following aspects of your work.” Items included “stress due to excessive work,” “stress due to work content,” “stress due to lack of decision making,” “stress due to unsatisfactory evaluation,” “not finding the work as worthy,” and “stress due to interpersonal relationships in the workplace.” Total scores were calculated by summing the scores of all items. The internal consistency coefficient for this measure was acceptable for this study, α = 0.79.Work-related distress over the past month was assessed with six items. Respondents answered the extent to which they felt stressed in six aspects of work using a 5-point scale ranging from 1 , marital status (married or single), years of experience working as a public health nurse, and the presence of lifetime traumatic experiences (yes or no).Between July 27, 2015, and August 31, 2015, we distributed a paper-pencil version of the survey to all potential participants through the Japanese Nursing Association, the nursing associations in these four prefectures, and the Japanese Association of Public Health Nurses.We used the R version 4.0.5 for all statistical analyses . As a vaSecond, as a person-centered approach, we conducted a latent profile analysis using a Gaussian finite mixture model for scores of empathic concern, personal distress, perspective taking, fantasy, and STS using the R package mclust . To confAdditionally, we conducted a series of one-way ANOVAs to compare scores of each subscale of empathy, burnout, and STS between the groups classified by the latent profile analysis. We conducted chi-square tests for the difference in the categorical variables among the categorized groups using the R packages RVAidememoire .  had missing data. We imputed these missing data with a random forest imputation algorithm using the R package missForest , 34.The participants (97.2% women) worked in the Tohoku (69.0%) or Saitama 31.0%) regions. Approximately 70% were married (68.1%). Most reported no lifetime traumatic experiences before the 2011 Great East Japan Earthquake (77.8%). The number of years of experience as a public health nurse varied  to Step 2 (R2adj = 0.26), F = 24.81, p < .001. In Step 2, working in Saitama prefecture, lifetime traumatic experiences and work-related, and personal distress were associated with higher STS scores. Emotional support was related to lower STS scores . Results showed that the model improved from Step 1 (R6), F4, 7.60 = 24.n = 102, 10.1%), Group 2 , Group 3 , and Group 4 . Other classifications with different numbers of groups yielded smaller BIC values . These four groups comprised Group 1 (ps < 0.001 (Table 2(3) = 32.96, p < .001. The post-hoc follow-up test showed a significant difference between Group 1 and Group 3 (adjusted p < .001) and between Group 1 and Group 4 (adjusted p < .001). There was a difference in lifetime traumatic experiences depending on the groups, χ2(3) = 47.2, p < .001. Results of the posthoc comparisons showed a significant difference between Group 1 and Group 2 (p = .03), Group 1 and Group 3 (p < .001), Group 1 and Group 4 (p < .001), and Group 2 and Group 4 (p = .039). We ran a Fisher’s exact test for gender and the group because two cells had fewer than 5 participants. Results of a Fisher’s exact test showed that gender was not different among the groups, p = .647.We conducted a series of one-way ANOVAs and chi-square tests to compare the study variables between the groups identified in the latent profile analysis. We used the Benjamini-Hochberg procedure to adjust the false discovery rate for the follow-up tests . The Ben01 Table . The freThe present study explored the psychological distress among a sample of Japanese public health nurses, and its association with dispositional empathy. First, we examined variables that could have been associated with STS using a variable-centered approach. The results showed that STS was associated with personal distress, lifetime traumatic experiences, and work-related stress. Additionally, higher perceived support scores were related to lower STS scores, consistent with previous findings . Higher Even though personal distress does not always lead to STS, it contributes to the development of STS in several ways . One sucAnother possibility is that empathy and STS have a nonlinear relationship. There might be an empathy threshold where empathy affects STS more strongly. This model is often depicted as a cusp catastrophe model . Some emFurthermore, coping strategies can affect the relationship between dispositional empathy and STS. For example, higher empathy is related to lower avoidant coping , which is further related to lower psychological distress among Japanese workers . When emOur person-centered approach found that our sample of public health nurses could be classified into four groups based on dispositional empathy and STS levels. Group 1 had the highest STS level, with higher personal distress than Groups 3 and 4. This group reflects the findings of the variable-centered approach, demonstrating the association between high personal distress levels and high STS levels. Compared to Group 1, Group 2 presented moderate STS, a lower level of perspective-taking, higher levels of empathic concern and fantasy, and almost equivalent but the highest level of personal distress. Based on previous studies, personal distress has consistently been negatively associated with mental well-being, such as compassion satisfaction, and positively associated with negative psychological responses, such as STS and burnout , 18, 43.Elevated empathic concern, personal distress, and fantasy can influence a positive psychological response to help others. Interestingly, in addition to Groups 1 and 2 having relatively lower professional efficacy, they had the highest personal distress. Moreover, Group 2 also had the highest empathic concern, characterized by highly identifying their feelings with others’ sufferings. These characteristics might hinder their ability to have positive attitudes toward their work . These findings suggest the nuanced nature of dispositional empathy concerning the consequences of caring.Further examinations revealed that Group 3 had higher personal distress and burnout  than Group 4. Burnout has the same patterns as STS, with Group 1 having the highest burnout and Group 4 having the lowest. These findings are consistent with other findings that burnout can be a vital precursor to future STS .In comparing the presence of lifetime traumatic experiences between the groups, the frequency was higher in the order of Groups 1 to 4. This trend might contribute to the lower STS levels in Group 2 than in Group 1, even though they have equivalent levels of personal distress. These findings indicate that participants with lifetime traumatic experiences are more likely to be classified into groups with relatively high STS and personal distress. Consistent with these findings, a meta-analysis showed that STS and personal traumatic history had a small but positive effect size (r = .19) in professionals working with people suffering from trauma . The preThis study included an unexpected finding in the relationship between the region and STS. The finding indicates that public health nurses in Saitama had higher STS than those in the Tohoku region where the 2011 Great East Japan Earthquake occurred. Although speculative, this unexpected finding might be due to two reasons. Many public health nurses from other regions  went to the Tohoku region to support the public health nurses working there. As such, they might have enhanced perceived support, reducing STS. Additionally, Saitama is in the Tokyo metropolitan area and has fewer public health nurses per population than the Japanese national average . Due to Despite demonstrating that classifying public health nurses based on dispositional empathy and STS provides new insights into the role of dispositional empathy, this study has several limitations. First, this is a cross-sectional study. We could not test the effect of dispositional empathy in classifying public health nurses over time. Future studies must investigate how STS or burnout changes across these four groups over time. Furthermore, our study provides potentially useful information on different classes based on dispositional empathy and STS. These findings should be replicated in other populations of nurses or other healthcare professionals. As latent profile analysis is sensitive to slight changes in the data, different occupations might have distinct classifications.The present study examined the relationship between dispositional empathy and STS in the variable-centered, including person-centered approaches. Our findings suggested four groups of public health nurses based on dispositional empathy and STS in the person-centered approach, which enables us to identify nuances among the groups that the variable-centered approach could not. In addition, we demonstrated that personal distress is associated with STS in the variable-centered approach. Despite its several limitations, this study provides new insights into the roles of dispositional empathy in Japanese public health nurses. Future studies must replicate our findings and investigate more differences between the classes we identified in this study.Below is the link to the electronic supplementary material.Supplemental Material. R codes for the data cleaning, data processing, and data analysis.


Neuronal action potential firing patterns are key components of healthy brain function. Importantly, restoring dysregulated neuronal firing patterns has the potential to be a promising strategy in the development of novel therapeutics for disorders of the central nervous system. Here, we review the pathophysiology of essential tremor and Parkinson's disease, the two most common movement disorders, with a focus on mechanisms underlying the genesis of abnormal firing patterns in the implicated neural circuits. Aberrant burst firing of neurons in the cerebello‐thalamo‐cortical and basal ganglia‐thalamo‐cortical circuits contribute to the clinical symptoms of essential tremor and Parkinson's disease, respectively, and T‐type calcium channels play a key role in regulating this activity in both the disorders. Accordingly, modulating T‐type calcium channel activity has received attention as a potentially promising therapeutic approach to normalize abnormal burst firing in these diseases. In this review, we explore the evidence supporting the theory that T‐type calcium channel blockers can ameliorate the pathophysiologic mechanisms underlying essential tremor and Parkinson's disease, furthering the case for clinical investigation of these compounds. We conclude with key considerations for future investigational efforts, providing a critical framework for the development of much needed agents capable of targeting the dysfunctional circuitry underlying movement disorders such as essential tremor, Parkinson's disease, and beyond. Essential tremor (ET) and Parkinson's disease (PD) are the two most common movement disorders worldwide. In the United States, an estimated 7 million individuals have ET, representing approximately 2% of the total population,Aberrant neuronal activity has been implicated in the pathology of several neurologic conditions, including epilepsy, tinnitus, neuropathic pain, dystonia, ET, PD, and major depression.The search for pharmacologic options has led to identification of various approaches to modulating neural circuit activity in the CTC and BG. One of the most promising targets are T‐type calcium channels (TTCC), known to be involved in the generation of burst activity in several brain areas.V3; −70 to −55 mV)V1 and CaV2; > −40 mV).TTCCs—named “T‐type” due to their transient calcium conductance—are low voltage‐activated calcium channels with key roles in membrane excitability.V3.1,V3.2,V3.3V3.1, CaV3.2, and CaV3.3 are encoded by the genes CACNA1G (chromosome 17), CACNA1H (chromosome 16), and CACNA1I (chromosome 22), respectively.V3.1 channels are expressed in the soma and dendrites of neurons in several brain regions including the cerebellum, thalamus, hypothalamus, olfactory bulb, basal ganglia, cortex, and hippocampus, as shown by rodent and human data.V3.1 is to regulate the oscillatory activity of thalamic neurons, as first described in cat dorsal lateral geniculate nucleus.V3.1 in mouse and human cerebellumV3.1,V3.2 channels in mouse are predominantly expressed in the hippocampus (dentate gyrus),V3.2 channels have been shown to control NMDA receptor‐mediated transmission at central synapses in cultured rat hippocampal cells expressing the human variant.V3.2 are also required for acute pain perceptionV3.3 channels are similarly expressed in various brain regions in both mouseV3.3, and to a lesser extent CaV3.2, plays the dominant role in sleep spindle rhythmogenesis, whereas CaV3.1 appears to play a minimal role in sleep spindle activity.V isoform plays in the generation and/or regulation of sleep spindles.Cathalamocortical oscillations, spike–wave discharges, and neuropathic pain.A key function of TTCCs is to regulate neuronal firing patterns Figure .86, 8CACNA1G gene encoding the CaV3.1 isoform have been reported in three families based on whole exome (of 37 families) and whole genome (of eight families) sequencing studies of familial ET; however, corresponding functional studies showed little to no change from wild type.Essential tremor (ET) is characterized by a 4–12 Hz postural and action tremor, primarily affecting the upper limbs but often accompanied by head and voice tremors.CACNA1G have been shown to eliminate tremor in a harmaline mouse model,pcd mice with some PC degeneration but intact climbing fibers have an attenuated response to harmaline administration, with reduced tremor frequency and amplitude relative to wild‐type mice.Lurcher mice which lack PC neurons and climbing fibers do not develop tremor upon harmaline administration.+) excitatory neurons results in action tremor in mice, and DCN synaptic transmission block reverses the tremor.Animal models have provided insights into the mechanisms underlying tremor generation, the most common of which is the harmaline rodent tremor model.Grid2dupE3 mouse model is a recently developed tremor model for ET, in which mice have a genetic mutation of the Grid2 gene (exon 3 duplication) that leads to increased protein degradation and reduced GluRδ2 cerebellar expression levels, resembling the GluRδ2 deficiency observed in patients with ET.Grid2dupE3 mice results in aberrant climbing fibers extending into parallel fiber synaptic territory,Grid2dupE3 mice develop 20 Hz cerebellar oscillatory activity (coherent with action tremor), which can be dampened by ethanol and first‐line agents used to treat patients with ET, including propranolol and primidone.Grid2dupE3 mice,The V3.1 pore domain.Despite the growing body of preclinical evidence, there has been a paucity of studies on the effects of TTCC blockers on human tremor. Moreover, few selective TTCC blockers exist. For example, 1‐octanol and its primary metabolite octanoic acid have shown evidence of tremor reduction in adults with ET.PD is clinically manifested by cardinal symptoms of bradykinesia (slowness of movement), rigidity, or stiffness that impedes normal motor activities, and/or rest tremor.Although effective, long‐term levodopa therapy can eventually lose efficacy or lead to dyskinesia and hallucinationsWhile much of our understanding of the dysfunctional circuitry in PD to date has come from observations of abnormal bursting activity in primate models or in patients with PD, data comparing the brain activity of patients with PD to healthy participants, or to patients with PD before disease onset, are lacking. In one study comparing advanced and early PD, patients with more advanced PD were shown to have neurons that fire at a higher rate while demonstrating higher overall level of STN background activity.A specific role for TTCCs in modulating the underlying circuit dysfunction in PD can be inferred from preclinical studies, which allude to TTCC involvement in burst firing within BG circuit nodes, notably the STN. The abnormal bursting activity in the BG circuit associated with PD has been causally linked to TTCC activity in preclinical models. A TTCC blocker, ML218, inhibits TTCC current and consequently reduces low threshold spike and rebound burst activity in STN neurons in ex vivo thalamic slices, and further reverses haloperidol‐induced catalepsy in a rat model of PD.While the electrical underpinnings of bradykinesia and rigidity seem to relate, at least in part, to disrupted TTCC modulation of BG motor circuits, the mechanisms underlying PD tremor are less clear. Preclinical PD tremor research is particularly scarce due to the lack of a robust rest tremor model.As with ET, few studies have focused on the effectiveness of TTCC blockers in PD tremor. In the rat tacrine‐induced tremulous jaw movement model (used to mimic parkinsonian tremor),V isoforms may lead to the development of treatments targeted to critical neuronal circuit nodes in ET and PD.The concept of treating ET and PD as diseases of dysfunctional circuitry represents an important paradigm shift in the management of movement disorders. The development of agents with novel mechanisms of action that can pharmacologically mimic the effects of DBS has the potential to provide much needed alternatives to invasive surgical interventions. While identifying suitable targets for pharmacologic intervention has been challenging, the current mechanistic exploration of ET and PD points to consistent patterns of disrupted circuitry, including cerebellar and thalamic rhythmic oscillations in ET and STN burst firing in PD. Importantly, TTCC activity appears to be implicated in both ET and PD circuit pathophysiology, with TTCC blockade emerging as a promising therapeutic strategy for alleviating the motor symptoms of these movement disorders Figure . MultiplWe conclude with some considerations for future investigational efforts. To successfully measure the effect of TTCC blockers on motor symptoms, studies need to be designed carefully to (i) optimize CNS target engagement and drug titration, and (ii) monitor/minimize potential adverse events. Firstly, differences in efficacy among TTCC blockers may reflect differences in CNS penetrance, with some agents more able to cross the blood–brain barrier. Assessing target engagement in response to TTCC blockade via CNS pharmacodynamic biomarkersConceptualization and literature review: Lillian G. Matthews, Corey B. Puryear, Susana S. Correia, Sharan Srinivasan, Gabriel M. Belfort, Ming‐Kai Pan, and Sheng‐Han Kuo. Analysis and interpretation: Lillian G. Matthews, Corey B. Puryear, Susana S. Correia, Sharan Srinivasan, Gabriel M. Belfort, Ming‐Kai Pan, and Sheng‐Han Kuo. Visualization: Lillian G. Matthews, Corey B. Puryear, Sharan Srinivasan, Gabriel M. Belfort, and Sheng‐Han Kuo. Writing—original draft: Lillian G. Matthews, Corey B. Puryear, Susana S. Correia, and Sharan Srinivasan. Writing—review and editing: Lillian G. Matthews, Corey B. Puryear, Susana S. Correia, Sharan Srinivasan, Gabriel M. Belfort, Ming‐Kai Pan, and Sheng‐Han Kuo. All authors read and approved the final article.Funding for editorial support was provided by Praxis Precision Medicines. SHK is supported by NINDS #R01 NS104423, NINDS #R01 NS118179, and NINDS #R01 NS124854.LGM serves as a paid consultant to Praxis Precision Medicines and is a Praxis shareholder. CBP, GMB, and SC were employees of Praxis Precision Medicines during article preparation and are Praxis shareholders. MKP and SHK serve as scientific advisors for Praxis Precision Medicines and Sage Therapeutics.Figure S1Click here for additional data file.


Vairimorpha apis and V. ceranae are known to cause intestinal infection in honey bees and are associated with decreased colony productivity and colony loss. The widely accepted method for determining Vairimorpha colony infection level for risk assessment and antibiotic treatment is based on spore counts of 60 pooled worker bees using light microscopy. Given that honey bee colonies consist of as many as 1,000 times more individuals, the number of bees collected for Vairimorpha detection may significantly impact the estimated colony infection level, especially in the case of uneven distribution of high- and low-infected individuals within a hive. Hence, we compared the frequency and severity of Vairimorpha infection in individual bees to pooled samples of 60, 120, and 180 bees, as well as compared the Vairimorpha spp. prevalence in pooled samples of 60 and 180 bees. Overall, we did not find significant differences in spore counts in pooled samples containing incremental numbers of bees, although we observed that, in less-infected colonies, a low frequency of highly infected individuals influenced the estimated colony infection level. Moreover, Vairimorpha spp. prevalence did not differ significantly among the pooled bee samples tested. Increasing the number of pooled bees from the recommended 60 bees to 180 bees did not yield a more accurate representation of colony infection level for highly infected colonies, but the clinical importance of a low frequency of highly infected individuals in less-infected colonies needs to be addressed in future studies.The microsporidian pathogens  Apis mellifera) plays a crucial economic and ecologic role in providing pollination services for agriculture and global food production. However, managed honey bees are faced with a large variety of biotic and abiotic stressors such as the fungal pathogens Vairimorpha apis and V. ceranae , which cause severe and sometimes fatal disease in adult bees. Clinical signs of vairimorphosis (nosemosis) include dysentery with nutritional stress and malnutrition, shortened lifespan, impaired flight ability, and disorientation in individual forager bees in correlation with reduced colony productivity as a result of poor foraging performance and brood care.25 At the colony level, Vairimorpha spp. infection weakens colonies and increases the risk of overwinter mortality, accompanied by high economic losses for the beekeeping industry.11 The widely accepted method for estimation of Vairimorpha spp. infection at the colony level is to collect 60 forager bees from the hive entrance in spring and fall, macerate the bees to extract intestinal contents, followed by a microscopic spore count in a hemocytometer to estimate the spore load per bee.21 The total number of bees in a colony ranges from ~20,000 during early spring to ~60,000 during late summer, with 30% of the oldest bees in a colony being foragers, and reportedly having the highest spore loads in a colony.27 Considering that only a small portion of bees (0.1–0.3%) is used for estimation of the colony infection level, the true parasite burden and the distribution of infection levels of individual bees inside a colony may not be reliably reflected with a sample size of 60 foragers.21Vairimorpha spp. surveillance of our research apiaries (~200 hives) in the summer of 2021 revealed highly variable spore counts and Vairimorpha spp. composition in sequential samples (containing 60 bees) from the same hive within one day and on the following days (Suppl. Table 1), which is in strong concordance with another report of the variation in Vairimorpha species prevalence after subsequential sampling.The Western honey bee  compared the average number of spores per bee determined in incremental, pooled samples of bees; 2) counted spores in individual bees to determine the frequency of severely versus mildly infected bees, and 3) compared the ratio of V. apis to V. ceranae in individual bees and in incremental, pooled samples of bees. A pooled sample can consist of a low number of highly infected bees or an equal distribution of moderately infected bees, resulting in a similar calculated spore count per bee. Accordingly, we analyzed the frequency of spore levels in individual bees and correlated it to pooled samples to find a reliable number of bees to represent the colony infection level . Moreover, single bees can be infected with one or both Vairimorpha species, so we determined the species composition in pooled samples with quantitative real-time PCR (qPCR) to correlate the species ratio with sample size (objective 3).To evaluate the effect of sampling methods on estimation of Vairimorpha infection by microscopy and qPCR (60 bees per colony), and 21 colonies were identified as not infected. All colonies were treated with label dosages of oxytetracycline and amitraz, for control of American foulbrood and Varroa mites, respectively, per our region’s standard beekeeping practices. In October 2021, after colonies were wrapped for outdoor overwintering, we randomly assigned the 21 Vairimorpha-free colonies into 3 experimental groups , with 7 colonies per group. Colonies assigned to the low- and high-dose groups were inoculated with 90 × 106 and 900 × 106Vairimorpha spores, respectively (90 mL of homogenate containing 106 or 107 spores/mL); colonies in the control group were administered 90 mL of a sucrose solution. Vairimorpha spores for the inoculum were obtained from ~1,000 bees from a donor colony that was determined by qPCR of 60 bees to be infected with 50% of both Vairimorpha species. To prepare the inoculum, we crushed the bees in a blender with NH4Cl to avoid spore germination and mixed the spores with 2:1 (w/v) sucrose syrup to the final concentration, having 1:1 (w/v) sucrose syrup in the final suspension. We applied the spore suspension in the inter-frame spaces directly on the bee cluster of the top super (box) with a syringe  in October 2021, before inoculation, when colonies were already wrapped for outdoor overwintering, and again in March 2022, coinciding with the first visual overwinter survival assessment.2O, and the 3 subsamples containing 60 bees were each homogenized with 60 mL of sterile dH2O. To generate pooled samples of 120 and 180 bees, we combined 400 μL of two 60-bee subsamples (= 120 pooled bees) and 400 μL of three 60-bee samples (= 180 pooled bees). Vairimorpha spore loads per bee were determined by evaluation of a 10-μL aliquot of each individual or 60-, 120-, or 180-bee sample using a hemocytometer and light microscope. Additionally, genomic DNA was extracted from the 60- and 180-bee samples , and Vairimorpha species composition was determined by qPCR with species-specific primer–probe combinations based on the small ribosomal subunit rDNA. The Ct values from qPCR were transformed to spore numbers using the slope function from duplicate standard curves prepared from 10-fold diluted spores (107–10 spores) of each species.We collected ~300 bees with a vacuum from the lid of the top super in March, April, and May 2022 from all live colonies. Bees were divided into subsamples of 3 × 60 bees and 30 individual bees. Single bees were each macerated in 500 μL of sterile dHhttps://www.r-project.org/) and an α = 0.05 significance level. Normality was assessed with the Shapiro–Wilk test. The number of surviving colonies was compared by treatment group and sampling time using the Pearson χ2 test. Vairimorpha spore counts and species prevalence were compared among pooled samples using repeated measures one-way ANOVA with a post hoc paired t-test and Wilcoxon matched-pairs signed rank test, respectively. The effect of treatment and sample size on species prevalence was determined by 2-way ANOVA. One-way ANOVA or the Kruskal–Wallis test were used to analyze the interaction effect of sampling time and treatment on cluster size and Varroa infestation. The correlation between colony infection level and frequency of infection severity or intensity (non-infected to highly infected) or Vairimorpha spp. prevalence was assessed with the Pearson correlation.All statistical tests were conducted with R v.4.2.2 . Surviving colonies in all groups had significantly decreased colony strength from October 2021 to March 2022  = 113.247, p < 0.0001), but the colony strength did not differ significantly among the control and infected groups at each time  = 1.071, p = 0.353; Varroa infestation did not differ significantly among treatment groups  = 1.938, p = 0.214; Of 21 colonies, 10 survived until March 2022, with a statistically nonsignificant dose-response in colony survival  = 3.754, p = 0.034) dose-response in Vairimorpha infection level in April 2022, with mean spore counts in control, low-dose, and high-dose groups of 7.3 ± 5.7 × 106, 9.7 ± 9.2 × 106, and 14.2 ± 5.9 × 106 spores/bee, respectively, based on the mean spore counts in 60, 120, and 180 bees. The mean spore count per bee in 30 individually analyzed bees, and 60, 120, and 180 pooled bees was not statistically different within each treatment group  = 5.505, p = 0.0717; low-dose F = 2.019, p = 0.3904; high-dose F = 1.324, p = 0.4555), nor among the treatment groups  = 0.846, p = 0.4823), and the interaction of treatment and sampling method (pooled sampling) was nonsignificant  = 0.033, p = 0.9998; There was a significant . Colonies with similar mean Vairimorpha spore loads per bee based on a pooled sample also had a comparable distribution of individual bees with different infection intensities , nor among the treatment groups  = 0.046, p = 0.955) or the combination of treatment and number of bees per pooled sample  = 0.014, p = 0.986; Vairimorpha spp. ratio was 61.9–99.9% V. apis to 0.01–38.1% V. ceranae; the trend toward increased V. apis prevalence with increased mean spores per bee based on pooled samples was nonsignificant . Moreover, an increasing percentage of non-infected bees per colony .The species prevalence did not differ significantly between samples of 60 or 180 bees from each colony . Recent literature suggested a replacement of V. apis by V. ceranae, which is contradictory to our findings.22 One explanation for this discrepancy is that V. ceranae spores in our experiment may have lost viability during the inoculum preparation, resulting in a higher V. apis prevalence in spring. Hence, our results are not in concordance with the occurrence of V. ceranae spring peaks shown for overwintering colonies in Ontario, Canada. Interestingly, colonies 5 and 6, which had mainly uninfected bees, revealed a higher V. ceranae proportion (~32%) than the other colonies (< 10%).The number of pooled bees does not appear to influence the Vairimorpha spp., including high colony mortality and contamination of control colonies. Given the high overwinter mortality of our experimental colonies, we could sample only 10 of 21 colonies in spring 2022. Furthermore, spring Vairimorpha spp. infection levels in the control colonies were similar to the low- and high-dose colonies. Given the lack of protocols and studies using experimental Vairimorpha spp. infection at the colony level, we may have used exceedingly high spore doses for inoculation, ultimately resulting in high colony mortality. Also, the proximity of control colonies to Vairimorpha spp.–inoculated colonies in the same apiary may have resulted in Vairimorpha spp. transmission to control colonies through robbing of contaminated honey stores in dead or weak low- and high-dose colonies.Our study highlights the difficulties of conducting experimental, colony-level infection with Vairimorpha spp. infection intensity in individual bees. Our data will subsequently contribute to evaluation of antibiotic treatment strategies and the effect of treatment in colonies with a low frequency of highly infected individuals.Hence, we need further colony-level studies with higher sample sizes and non-contaminated controls to investigate the clinical importance of the frequency of Click here for additional data file.Supplemental material, sj-xlsx-1-jvd-10.1177_10406387231194620 for Comparison of individual and pooled sampling methods for estimation of Vairimorpha (Nosema) spp. levels in experimentally infected honey bee colonies by Sarah Biganski, Tessa Lester, Oleksii Obshta, Midhun S. Jose, Jenna M. Thebeau, Fatima Masood, Marina C. B. Silva, Marcelo P. Camilli, Muhammad F. Raza, Michael W. Zabrodski, Ivanna Kozii, Roman Koziy, Igor Moshynskyy, Elemir Simko and Sarah C. Wood in Journal of Veterinary Diagnostic Investigation


P ≥0.128). Gilt feed efficiency was improved during the second phase compared to barrows; however, feed efficiency was not different between barrows and gilts during the first and third phases; resulting in a similar feed efficiency between sexes for the overall period (P = 0.523). Compared to HUS, gilts receiving LUS had higher ADFI overall (P = 0.018), which translated into improved G:F for HUS gilts (P = 0.011). Overall, gilts receiving the 20:1 diet tended to have improved G:F compared to 12:1 (P = 0.086). ADG was improved in pigs fed diets formulated with unsaturated fat sources to a 20:1 LA:ALA, regardless of sex. Detection of first estrus by 235 d of age in gilts was not impacted by U:S or LA:ALA (P ≥ 0.356). In conclusion, feeding differing dietary U:S and LA:ALA ratios impacts growth of growing pigs, particularly improving feed efficiency of gilts fed diets with unsaturated fat sources or a 20:1 LA:ALA. Further investigation into the physiological mechanisms differentially affecting gilt growth when fed varying dietary LA:ALA is warranted to understand the impact on reproductive outcomes.The objective of this study was to investigate the effects of dietary unsaturated and saturated fat ratio (U:S) and the ratio of linoleic and linolenic acid (LA:ALA) on the growth performance of grow-finish pigs and estrus detection of gilts. A total of 240 pigs with initial body weight (BW) 54.4 ± 5.5 kg were randomly assigned to a high  or low  U:S in combination with a high (20:1), moderate (12:1), or low (4:1) LA:ALA in a 3 × 2 factorial arrangement. Dietary ratios were achieved using blends of choice white grease, beef tallow, corn oil, flaxseed oil, or palm kernel oil. Diets were fed across three phases and balanced for energy and LA. Pigs were housed across 60 pens with either four gilts or four barrows per pen. On day 49, 1 gilt per pen was moved to individual housing at approximately 154 d of age for evaluation of reproductive characteristics. Data were analyzed as repeated measures using PROC MIXED  with pen as the experimental unit and U:S, LA:ALA, sex, and their interactions as fixed effects. Initial BW was fit as a covariate. Within each phase, there were no differences in BW, daily gain (ADG), feed intake (ADFI), or feed efficiency (G:F) for U:S, LA:ALA, or their interaction when averaged across sex ( Dietary lipids are highly digestible energy sources for pigs; however, the digestion and utilization of those lipids are highly dependent on the source and degree of saturation . GeneralPrevious work in pigs has demonstrated that a dietary fat source high in unsaturated FAs can improve average daily gain ADG; ; howeverAll experimental procedures adhered to guidelines for the ethical and humane use of animals for research according to the Guide for the Care and Use of Agricultural Animals in Research and Teaching  and wereLawsonia intercellularis , porcine circovirus Type 2 and Mycoplasma hyopneumoniae  according to the manufacturer’s recommendations. Pigs did not display any clinical signs of disease and remained healthy throughout the 70-d trial.A total of 240 growing pigs  were individually weighed and randomly allotted to pens such that there were either four barrows or four gilts per pen, for a total of 60 pens. Pigs had an initial BW of 54.4 ± 5.5 kg. Pens had partially slated, concrete flooring with dimensions of 1.83 m × 1.93 m. This study was conducted during the summer months in a central Iowa research farm. Pigs originated from a porcine reproductive and respiratory syndrome virus (PRRSv) vaccinated herd. One pig per pen was vaccinated for Pens were randomly assigned to a high  or low  U:S with a high (20:1), moderate (12:1), or low (4:1) LA:ALA FA ratio in a 3 × 2 factorial design. The dietary LA:ALA ratios were selected based on previous research by Pigs were individually weighed and feed disappearance was recorded on days 0, 14, 42, and 70 to calculate ADG, average daily feed intake (ADFI), and gain to feed ratio (G:F) for pen within each phase. On day 49, one vaccinated gilt per pen was moved to individual housing (pen size = 1.41 m × 2.18 m) at approximately 154 d of age for evaluation of reproductive characteristics. One vaccinated barrow per pen was also removed to maintain equal pig space across all pens. Gilts remained on their experimental diets for the remainder of the study. Gilts were administered 4 mL of boar saliva pheromones  intranasally twice a day at 0630 and 1630 hours. Gilts were evaluated by trained researchers for signs of estrus, including standing heat, erect ears, swollen and red vulvas, and vaginal discharge. Upon detection of previously described signs of estrus, gilts stopped receiving boar pheromones.Eighteen days postestrus detection, gilts were administered 4 mL of boar saliva pheromones intranasally twice a day at 0630 and 1630 hours and observed for signs of estrus. Upon detection of their second estrus, gilts were euthanized by captive-bolt followed by exsanguination and the right ovaries were collected. Gilts that did not display signs of estrus by day 46 postplacement into individual housing were euthanized by captive-bolt followed by exsanguination and the right ovary was collected for evaluation of ovarian structure development to determine if gilts had cycled.Diets were ground to 1 mm particle size with a Wiley Mill  and analyzed in duplicate for dry matter (method 930.15 ), acid-hTotal lipids were extracted by using a chloroform and methanol mixture . The lipP-value from the model. Results were considered significant at P ≤ 0.05 and a trend at P > 0.05 and P ≤ 0.10.Growth performance data by phase were analyzed as repeated measures using the MIXED procedure of SAS 9.4 (SAS Inst.). Pen was the experimental unit, with U:S, LA:ALA, sex, phase, and their interactions included as fixed effects in the statistical model. Initial BW was fit as a covariate. The spatial power covariance structure was selected for the repeated measures model according to Bayesian information criterion. Statistical outliers were identified as occurring greater than three standard deviations from the mean of the studentized residuals and were excluded from the analysis. Normality and homoscedasticity of the studentized residuals were tested using the UNIVARIATE procedure. Data were reported as least-squares means and means separation was done using the PDIFF option. Gilt estrus detection data were analyzed using the GENMOD procedure of SAS 9.4 with a binary distribution and a logit link function. Data were reported as raw frequencies and percentages with the resulting P ≥ 0.461), ADG (P ≥ 0.128), ADFI (P ≥ 0.358), or feed efficiency (P ≥ 0.461) for the effects of U:S, LA:ALA, or their interactions , which translated into improved G:F for HUS gilts (P = 0.011). Limited data exist evaluating the interactions of dietary fat source and sex on pig growth performance. Barrows had higher final BW, ADG, and ADFI across each phase  or U:S × FA (P = 0.356). Minimal research has been completed investigating the optimum dietary FA profile for the developing gilt prior to puberty onset. Vaccinations were given prior to puberty to simulate commercial production practices in the gilt developer unit. Given the limited number of animals utilized in this subset and low detection of estrus overall, further research is needed to investigate the impact of dietary essential FAs on reproductive characteristics of developing gilts. Additionally, heat detection in this study occurred during the months of June and July in central Iowa. It is possible heat stress associated with high ambient temperatures during this time delayed the onset of puberty (Additionally, gilts receiving the 20:1 diet in the current study tended to have improved G:F compared to 12:1 for the days 0 to 70 period ( puberty . Photope puberty . It is h puberty . ChartraIn conclusion, the data presented herein demonstrates an improvement in feed efficiency of growing gilts when fed diets formulated with unsaturated fat sources. This improvement in feed efficiency was also observed in gilts fed a 20:1 essential FA ratio, independent of fat source. When feeding a diet containing unsaturated fats, a 20:1 LA:ALA improves gain over 12:1 essential FA ratio; however, a lower LA:ALA is optimal when feeding diets high in saturated fats. ADG was optimized in pigs fed diets formulated with unsaturated fat sources to a 20:1 LA:ALA, regardless of sex. Additional investigation into the biological mechanisms impacting the growth of gilts fed varying dietary essential FA ratios is needed to understand the potential positive or negative consequences on reproductive outcomes.


NOS, ARG, AZIN) and for Lyso.PC and PC  were related with overall survival. Further studies are required to verify these results with larger samples and other histologic types of lung cancer.The metabolic profile of cancerous cells is shifted to meet the cellular demand required for proliferation and growth. Here we show the features of cancer metabolic profiles using peripheral blood of healthy control subjects (n = 78) and lung adenocarcinoma (LUAD) patients (n = 64). Among 121 detected metabolites, diagnosis of LUAD is based on arginine, lysophosphatidylcholine-acyl (Lyso.PC.a) C16:0, and PC-diacyl (PC.aa) C38:3. Network analysis revealed that network heterogeneity, diameter, and shortest path were decreased in LUAD. On the contrary, these parameters were increased in advanced-stage compared to early-stage LUAD. Clustering coefficient, network density, and average degree were increased in LUAD compared to the healthy control, whereas these topologic parameters were decreased in advanced-stage compared to early-stage LUAD. Public LUAD data verified that the genes encoding enzymes for arginine ( Around 230,000 patients are newly diagnosed with lung cancer annually, and 130,000 died from lung cancer in the United States in 20214. Although deaths per 100,000 are decreasing, lung cancer shows the highest death rate among all cancers4.Lung cancer is one of the malignancies with the highest mortality and is second in incidence and fourth in prevalence worldwide. The global mortality and incidence of lung cancer were 18.0 and 22.4 per 100,000, respectively, in 20206. These biomarker metabolites can enhance our understanding of tumor biology and have potential for applied use in early diagnosis. Among them, acylcarnithines, amino acids, biogenic amines, lysophosphatidylcholines (LPCs), phosphatidylcholine (PC), and sphingolipids can be extracted from tissue, blood, serum, or body fluids. Arginine is an amino acid that is used for creatine and urea biosynthesis. In the kidney, proline, glutamate, and glutamine can be converted to citrulline and with aspartate can be synthesized to agininosuccinate and then to arginine by agininosuccinate lyase via the urea cycle9. Arginine is required for tumor cell proliferation; however, it is also required for normal lymphocytes, which could act as a double-edged sword in cancer treatment7.Metabolomics has supported genomics and proteomics to provide information regarding cancer metabolic processes that are related to tumor formation and/or proliferative potential10. Lung cancer cells dysregulate lipid metabolism, the effects of which are reflected in the peripheral blood9. LPC is a lipid biomolecule derived from PC by phospholipase A2 or from free cholesterol and fatty acids by lecithin cholesterol acyltransferase12. Cancer cells convert LPC to produce various PCs via LPC acyltransferase 1 (LPCAT1), and the PCs are utilized for plasma membrane remodeling13. Decreased LPC and increased PC concentration are found in cancer tissue and in the peripheral blood of cancer patients14.LPC and PC are precursors of membrane lipids related with plasma membrane remodeling in various cancersTo study the metabolic nature of lung cancer using peripheral blood, metabolites from healthy control and LUAD patient samples were compared. A statistical model was constructed based on these metabolites for early diagnosis of LUAD. Network analysis was performed to analyze these biomarkers among healthy controls and early and advanced LUAD patients.16. All patients were classified according to the World Health Organization definitions and according to the seventh edition of the tumor-node-metastasis (TNM) classification of the American Joint Committee on Cancer Staging Manual17. The TNM stages of the LUAD patients are presented  and LUAD cancer patients (n = 65) were analyzed in the study. All LUAD patients underwent surgical intervention, and the diagnosis was confirmed by a pathologist during routine diagnostic procedures® p180  kit is a MS-based assay for quantification of target metabolites in body fluids using stable isotope–labeled standards. The kit allows targeted analysis of 188 metabolites, covering a wide range of analytes and metabolic pathways in one targeted assay. Amino acids (21) and biogenic amines (21) are determined in the LC–MS mode; acylcarnitines (40), LPCs (14), PCs (76), sphingomyelins (15), and the sum of hexoses (1) were analyzed via flow injection analysis  followed by 10 μL of sample  were added to the filter inserts  of the 96-well plate and dried for 30 min under a nitrogen stream. Then, 50 μL of a 5% phenylisothiocyanate (PITC) solution was added to derivatize amino acids and biogenic amines and then incubated at room temperature for 1 h. After incubation, the metabolites and internal standards were extracted using 5 mM ammonium acetate in methanol (300 µL) into the lower 96-well plate for MS analysis. One-half of the eluate was measured by liquid chromatography (LC) LC–MS/MS, and the other half was determined by FIA-MS/MS.Analyses for amino acids and biogenic amines were performed using a Zorbax Eclipse XDBC18 column  at a flow rate of 0.5 ml/min with water:acetonitrile containing 0.2% formic acid in the LC gradient condition. Analyses for glycerophospholipids, sphingolipids, acylcarnitines, and hexoses were performed at a flow rate of 0.03 ml/min with elution solvent in FIA gradient conditions. Multiple reaction monitoring modes of the tandem mass spectrometer  in positive electrospray ionization (ESI) were used for quantification of target metabolites. However, only hexose was analyzed in negative ESI mode.18. Briefly, after pre-processing  with Analyst 1.5.1 software , data were uploaded into Biocrates MetIDQ software. The concentrations of metabolites determined by FIA were directly calculated in MetIDQ. Specifically, the concentrations of derivative metabolites consisting of amino acids and biogenic amines were quantified precisely with a seven-point calibration curve and internal standards, while the remaining metabolites corresponding to glycerophospholipids, sphingolipids, acylcarnitines, and hexoses were calculated semi-quantitatively based on specific stable isotope internal standard intensities. The final metabolite concentration was determined with inter- and intra-plate normalization using the median of three QC2 (from Biocrates Inc.) replicate injections of each plate compared to the target value.Quantification was carried out using internal standards and a calibration curve25. Node (N) indicates each metabolite, and link (L) indicates correlation between the nodes and plotted by a line. The average clustering coefficient (<C>) was defined as the friend’s friend, which was calculated as follows: Ci = 2Li/ki(ki-1), where Ci represents the clustering coefficient, Li represents the number of lines between neighbors of ki, and ki represents the node i with degree ki. Finally, <C>  = 1/N Ci = 0, none of the node i neighbors are linked. If Ci = 0.5, there is a 50% chance that the node i neighbors are linked. Network density was calculated as follows: density (d) = L/Lmax, where L indicates the number of links, and Lmax indicates the maximum probable links among the nodes. Increased density implies that there are more correlations between molecules. Network heterogeneity was calculated as follows: Heterogeneity  =  √variance(k)/mean(k), which implies that network heterogeneity is variance of the degree of a node divided by the mean degree number. Network centralization  shows the importance of certain nodes with high connection (degree) compared to other nodes, which was calculated as follows: A indicates adjacency matrix and n indicates the total number of nodes. Shortest path or average shortest path was calculated as follows: <l> = N(N-1), where i, j). Average degree (<k>) was calculated as follows: <k>  = 2L/N = dN(N-1)/N. These calculations are performed using a Netanalyzer that was attached to Cytoscape28. Assortativity and modularity were calculated using the igraph package29. Assortativity coefficient indicates the association of nodes with similar weights. Modularity indicates the tendency of nodes to cluster and to form groups or clusters20.Network topologic parameters were defined as followshttps://xenabrowser.net)31. Primary tumors were selected, followed by deletion of duplicate patient samples. Survival analysis of these expression datasets was conducted via the Kaplan Meier method using the R package. The arginine biosynthesis pathway was plotted with modification based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway (hsa00220) and on the work of Morris et al.32. The PC and LPC pathways were plotted with modification based on the respective KEGG pathway (hsa00564) and on the work of Lesko et al.33. Arginine, citrulline, ornithine, PC, and LPC concentrations from this study were interpolated using these pathways.To verify the tested results in this study, the LUAD dataset was used. The Genomic Data Commons (GDC) The Cancer Genome Atlas (TCGA) LUAD dataset from the National Cancer Institute was downloaded from the University of Santa Cruz (UCSC) Xena Browser platform  regression analysis was performed for selecting diagnostic factors using the glmnet R package35. To select variables, multivariate logistic regression analysis was performed using the glm R package36. In addition, network analysis was performed based on the correlation matrix by Pearson’s correlation analysis. Correlation coefficient and p-values were calculated using the Hmisc R package37. Correlation coefficients greater than or equal to 0.8 with statistical significance were selected. Unweighted, undirected networks were constructed with these selected nodes, and network topological studies were plotted using Cytoscape28. From public datasets, Kaplan Meier analysis was performed using the survival38 R package and plotted using the survminer R package41. For receiver operating characteristics curve analysis, the pROC R package was used42. Data were analyzed using dplyr and plotted using ggplot241. All the statistical analysis was performed using the R program43.Significance among the mean values for healthy and LUAD samples was measured using Mann Whitney U tests with unequal variance and Student’s Among the 188 targeted metabolites, 121 including acyl carnitines, amino acids, biogenic amines, glycerophospholipids, and sphingolipids were measured and detected. The mean and standard deviation of these metabolites are listed in Fig. As there were many variables and some showed collinearity, LASSO regression was performed, and independent variables related to LUAD diagnosis were investigated Table . OptimalROC curve analysis was performed for all variables in LUAD diagnosis. Area under the receiver operation curve (AUROC), cut off values, sensitivity, specificity, positive predictive value (ppv), and negative predictive value (npv) were calculated  and was shown to decrease mortality by 20% compared to a control group44. Most of the metabolic profiles showed differences between healthy controls and LUAD samples. Among the tested 188 metabolites, three were selected for early LUAD diagnosis, arginine, Lyso.PC.a.C16:0, and PC.aa.C38:3.Metabolic profiles could provide valuable information for early LUAD diagnosis. Metabolic shifts are noted in cancer cells and are a part of the metabolic adaptation required to meet high demand for energy production required for proliferation in cancer cells6. As regulatory T cell or myeloid-derived suppressor cells suppress the immune response and metabolize arginine through arginase-I, arginine supplementation boosted chemotherapy efficacy46. As arginine is a precursor of nitric oxide (NO), NO could have anti-tumor effects due to p53 accumulation, which could be a possible mechanism in LUAD46. In this study, arginine was increased in the plasma of LUAD patients. Increased arginine might trigger the formation of NO that could result in vascular proliferation and tumor growth48. As increased NO expression is related with unfavorable prognosis, increased arginine could also be related to unfavorable prognosis, although this requires further study.Arginine is required for biological systems including cell growth and immune response modulation. Arginine deprivation is related to caspase-dependent apoptosis, caspase-independent apoptosis, caspase-independent autophagic cell death, and necroptosis in various tumors51. In this study, except for one LPC or lysoPC.a.C28:1, every LPC was decreased in LUAD samples. Furthermore, Lyso.PC.a.C16:0 was included in the prognostic model, implying that LPC could be a crucial factor affecting cancer pathobiology51. Normally, LPCs are components of surfactants made by alveolar type II cells in the lung, and decreased LPC in lung cancer patients implies either consumption by cancer cells or conversion by LPCAT. PCs are used for membrane construction, and PC metabolism is reprogrammed for proliferation in cancer cells52. In this study, most of the measured PCs were increased in LUAD patients, and PC.aa.C38:3 was increased in the diagnostic model.Unexpectedly, Lyso.PC.a.C16:0 was decreased in LUAD samples. LPC is decreased in cells due to the activity of LPCAT, which is an LPC acyltransferase that catalyzes the conversion of LPC to PC. Previously, LPCAT has been reported to be increased in cancer patients; therefore, LPC might be decreased in cancer patients53. Network heterogeneity reflects the degree distribution of nodes, and increased heterogeneity implies the presence of a hub node. Biological genetic networks tend to be heterogeneous due to the presence of a hub gene that is related to many other genes. In this study, heterogeneity was lower in LUAD compared to the normal healthy control group, indicating decreased presence of a hub node. The small world property involves shorter paths between nodes and small parameter diameter. Shorter paths between nodes implies a fast response against external stimuli and adaptation to the external environment53, as observed in LUAD. Assortativity indicates relationships between hub and hub nodes, whereas dissortativity implies relationship between hub and non-hub nodes. In this study, there was no significant difference between the groups in assortativity. Modularity implies functional aspects of a network and was similar between the compared groups.Network analysis can analyze complex or multi-dimensional data without losing or omitting many data pointsIn conclusion, the metabolic profiles of healthy control and LUAD patients were compared. Diagnosis of LUAD was achieved using arginine, Lyso.PC.a.C16:0, and PC.aa.C38:3 biomarkers. Network analysis revealed that heterogeneity, diameter, and shortest path were decreased in LUAD. On the contrary, these parameters were increased in advanced-stage compared to early-stage LUAD. Clustering coefficient, network density, and average degree were increased in LUAD compared to the normal healthy controls, whereas these topologic parameters were decreased in advanced LUAD compared to early LUAD. Further studies are required to verify these results with larger samples and other histologic types of lung cancer.Supplementary Information.


While epidemiological studies have found correlations between light at night (LAN) and health effects, none has so far investigated the impacts of LAN on population mortality yet. We aimed to estimate the relative risk for mortality from exposure to LAN in Mainland China.This time-stratified case-crossover nationwide study used NPP-VIIRS to obtain daily LAN data of Mainland China between 2015 and 2019. The daily mortality data were obtained from the Disease Surveillance Point System in China. Conditional Poisson regression models were applied to examine the relative risk (RR) for mortality along daily LAN in each county, then meta-analysis was performed to combine the county-specific estimates at the national or regional level.2/sr increases in daily LAN were 1.08 (95%CI: 1.05–1.11) for all-cause mortality and 1.08 (95%CI: 1.05–1.11) for natural-cause mortality. A positive association between LAN and all natural cause-specific mortality was observed, of which the strongest effect was observed on mortality caused by neuron system disease . The results were robust in both younger and old, as well as in males and females. The more pronounced effect of LAN was observed in median LAN-level regions. Combined with an exposure–response curve, our study suggests a non-linear association between LAN and mortality in China.A total of 579 counties with an average daily LAN of 4.39 (range: 1.02–35.46) were included in the main analysis. The overall RRs per 100 nW/cmOur study shows LAN is associated with mortality in China, particularly for neuron system disease-related mortality. These findings have important implications for public health policy establishment to minimize the health consequences of light pollution.The online version contains supplementary material available at 10.1186/s12916-023-02822-w. It is estimated more than 80% of the population in the world may currently live under light pollution : all causes (codes A00–Z99), accident , self-harm (codes X60–X84), non-accident , nervous system disease (codes G00–G99), digestive system disease (codes K00–K93), urinary system disease (codes N00–N39), renal failure (codes N17–N19), cardiovascular disease , heart failure (codes I50), stroke (codes I60–I69), coronary heart disease , myocardial infarction , respiratory system diseases (codes J00–J99), asthma (codes J45–J46), chronic obstructive pulmonary disease , and cancer (codes C00–C97). “Urinary system disease” included renal failure; “cardiovascular disease” included heart failure, stroke, CHD, and MI; and “respiratory disease” included COPD and asthma. Based on tumor location, we then divided “cancer” into subtypes. “Cancers” included skin cancer, lip/oral/pharyngeal cancer, reproductive system cancer , hematologic cancer, lung cancer, gastrointestinal cancer, and breast cancer .https://ngdc.noaa.gov) at a spatial resolution of 750 m × 750 m. The data were started in April 2012, with wavelengths covering from 500 to 900 nm. VIIRS observes the LAN of the earth every 24 h, and the transit time of the NPP satellite is 1:30 a.m. at local time. LAN has a specified dynamic range of approximately 7 orders of magnitude from 3 × 10−9 to 0.02 W/cm2/sr [2/sr). The daily composite NPP-VIIRS LAN data from 2015 to 2019 was obtained from the website. Then, we estimated the objective measure of daily LAN for each included county from 2015 to 2019 based on its geocoded address from the NPP-VIIRS. The daily LAN at the county scale uses the tool “Raster Calculator” in ArcGIS 10.2. The collected LAN records are mainly outdoor artificial LAN. Due to inclement weather conditions, LAN data cannot be collected by artificial satellites on some days  carried by the Suomi National Polar-Orbiting Partnership (Suomi NPP) satellite  concentrations from 2015 to 2019 were derived from the China High Air Pollutants (CHAP) dataset (https://weijing-rs.github.io/product.html), with a spatial resolution of 1 × 1 km2. The CHAP dataset has been generated from MODIS/Terra + Aqua MAIAC AOD products together with other auxiliary data  using artificial intelligence by considering the spatiotemporal heterogeneity of air pollution [2.5 concentrations from the dataset are highly correlated with ground-based measurements (R2 = 0.94) [2.5 concentrations were assigned to each county based on the longitude and latitude of the address, through the Baidu Web service API of “Geocoder” with Python version 3.8.3 [https://cds.climate.copernicus.eu/) with a spatial resolution of 10 × 10 km. ERA5-Land has been produced by replaying the land component of the ECMWF ERA5 climate reanalysis. The daily humidity was estimated by combing temperature, dewpoint temperature, and pressure. The unit of daily PM2.5, daily temperature, and daily humidity were µg/m3, °C, and %, respectively.We also derived daily particular matter 2.5 (PMollution . The est = 0.94) . These don 3.8.3 . The dai2.5. In stage 2, we used random-effects models to pool the county-specific estimates for all counties or counties in different groups.In this nationwide observational study, we performed a two-stage analysis to calculate the association between daily LAN and daily mortality in China. In stage 1, we first examined the association between daily LAN and daily cause-specific mortality in each county by using a time-stratified case-crossover design, which has been widely used to assess the effects of environmental risk on adverse health events. In this design, all days during which mortality was reported were selected as the case days, while the control days were selected from the same month and year and matched by day of the week to the case days. To account for the relative risk (RR) of cause-specific mortality associated with an increase in daily LAN, this stage analysis applied a conditional Poisson regression model. To control for confounding effects of weather conditions, we also adjusted for daily temperature, daily humidity, and daily PM2.5 and temperature; model 2, adjusted by PM2.5 and humidity; and model 3, adjusted by temperature and humidity. To investigate the different lag structures in the model, we performed conditional quasi-Poisson regression to capture the delayed effects of LAN and PM2.5 for the lag 0, lag 1, lag 2, lag 3, and lag 0–1 (average of the present and previous day), respectively. We explored the potential overall lag effects of daily LAN and non-linear association with daily mortality using conditional quasi-Poisson regression combined with distributed lag non-linear model. In this model, a natural cubic smooth function with 7 degrees freedom (df) per year was introduced to account for trends in mortality and seasonality. To control potentially non-linear effects of weather conditions, natural spline functions with 6 df for temperature and 3 df for humidity were also introduced into the model.To test the reliability of the main results, we did a series of sensitivity analyses. We modified the modeling choices in stage 1: model 1, adjusted by PM2/sr; the second tertile means median LAN level 2.67–3.63 nW/cm2/sr; the third tertile means high LAN level: > 3.63 nW/cm2/sr). Low, median, and high LAN groups include 193 counties, respectively. We also carried out the same analysis for different LAN levels to further identify the effect of LAN. The post hoc comparisons with the Kruskal–Wallis test were performed to make sure whether the effects of LAN were similar in different subgroups.To further identify the potential effect modifiers, we also conducted a series of stratified analyses. Firstly, to assess whether the association between LAN and mortality differed across subpopulations, we conducted analyses stratified by age  and sex to confirm the robustness of our results. Secondly, all counties in Mainland China were categorized into 3 levels based on a 5-year average per capita gross domestic product (GDP) from 2015 to 2019, which were derived from the yearbook of statistics in China at provincial levels. Above the national 5-year average per GDP (unit of renminbi (RMB): 59,781.8) was regarded as a high economic level and less than 45,000 RMB as a low economic level. Low, median, and high economic level groups include 172, 198, and 209 counties, respectively. We pooled the county-specific estimates for counties in different economic groups. Thirdly, according to tertiles of the 5-year average of daily LAN estimates from 2015 to 2019, we divide all counties into three levels which correspond to low, medium, and high LAN levels, respectively . Two-tailed 2/sr. Daily average LAN (blue line) and daily number of death (red line) in Mainland China are described in Additional file A total of 579 counties in Mainland China with available data on LAN and mortality were included in the present study during 2015–2019. The spatial patterns of average daily LAN estimations during the study period for each included county in Mainland China were presented in Fig. 2/sr increase in daily LAN was associated with all-cause mortality  and natural-cause morality , while mortality from external causes was not related to LAN  , nor between males and females (P = 0.89).When we repeated our analysis within different subgroup populations, our results did not change after stratified by age and sex. Similar to the nationwide estimates, the all-cause and natural cause mortality burden caused by LAN were still robust in various subgroups, while external cause mortality was still statistically insignificant Table . EstimatP = 0.42). The relationship between daily LAN and mortality was consistent across different levels of economic development (Table P = 0.02). Within the median LAN level regions, there is evidence for more significant associations between daily LAN and mortality , which contains pacemaker neurons that drive rhythm . Indeed,In 2007, a statement from The World Health Organization classified shift work that disrupted human circadian rhythms as a probable human carcinogen . RecentlOur study found that LAN exposure also affects cardiovascular mortality, especially heart failure. This result supports previous findings showing that LAN was linked to a higher risk of cardiovascular disease , 39. A pIn the sub-analysis of specific diseases, the results also showed a stronger association between LAN and renal failure. Consistent with our results, a Chinese cross-sectional study reported that night light index (NLI) at a 5-year moving average was significantly associated with an increased risk of chronic kidney disease prevalence . OkuliarThis study had several major strengths. First, to our knowledge, it is the first nationwide investigation of the adverse impact on the mortality of LAN. Compared with previous studies confined to individual cities, our study included 579 counties in China, which provided robust evidence with reliable representatives for our findings. Our findings provide an ecological association between LAN and mortality based on data at the county level, which will be quite important for subsequent policy at the national level, to deal with the abuse of LAN. Secondly, compared with the traditional Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) nighttime light data, the NPP-VIIRS light data at night have a higher spatial resolution, higher data quality, and no over-saturation problem . Higher There were several limitations to consider. First, we used the nighttime light imagery to evaluate LAN at the county level as surrogate data of individuals’ LAN exposure, which may lead to misclassification of LAN exposure. There are possible variations within the same county based on subject residences. However, previous epidemiological studies regarding other environmental risk factors have used the same approaches to estimate exposure levels. Secondly, we cannot adjust for some potential residual confounding effects at individual levels, including indoor light intensity, wearing an eyepatch, and sleep patterns, all of which may interact with LAN. Thirdly, although we have adjusted for atmospheric pollution and climate, we cannot entirely rule out that LAN exposure may be confounded by noise or other unrecognized environmental factors, which may interact with LAN to influence mortality.In conclusion, our study provides comprehensive evidence of positive associations between daily LAN and daily mortality caused by all natural causes, especially for neuron system disease-related mortality. By capturing the population exposed to a wide range of LAN levels in China and including objective measures of other environmental risk factors, our study adds to evidence that LAN is having profound impacts on public health, which substantially extent the existing knowledge. The findings on a national level can help improve public health practices to reduce the disease burden associated with LAN and call for policies on strategies for abating them.Additional file 1: Table S1. Summary descriptive statistics on average number of daily deaths in 579 Chinese counties stratified by sex and age, 2015-19. Table S2. RR and 95%CI of daily mortality associated with a 100 nanoWatts/cm2/sr increase of daily light at night levels for three models. Table S3. RR and 95% CI for association between daily mortality and a 100 nanoWatts/cm2/sr increase of daily light at night levels for different lag structure. Fig. S1. Basic information about average daily light at night (nanoWatts/cm2/sr) and daily number of deaths. Fig. S2. RRs and 95% CIs of mortality associated with daily light at night level on different lag days during 2015-2019.