To analyze the association between the pattern of sedentary time (bouts and breaks) with academic performance, with an emphasis on the mediating role of self-concept.Participants in the cross-sectional study were 394 adolescents (208 girls), aged 10–14 years, from sixth grade from Londrina, Paraná, Brazil. The sedentary time pattern was measured through accelerometry. Definitions: sedentary bouts — uninterrupted periods of sedentary behavior; breaks — non-sedentary period between two sedentary bouts. The self-concept was estimated using the Piers-Harris II Inventory. Academic performance was obtained by school grades.Short sedentary bouts were associated with higher academic performance in boys  and girls . Long bouts (30 minutes) were associated with lower academic performance in boys  and girls . For girls, total and intellectual self-concept mediated the association between all sedentary pattern and academic performance . For boys, the total (56.4%) and intellectual (82.9%) self-concept mediated only the association between bouts of 5–14 minute and academic performance.The pattern of sedentary time is associated with academic performance in adolescents and this association is mediated by self-concept, especially in girls. Even during adolescence, sedentary behavior has been associated with increased overweight and obesity, metabolic and cardiovascular markers, declined cognitive function, depressive symptoms, and reduced self-esteem and self-concept.Besides the documented evidence on the association between physical inactivity and several negative health outcomes, in children and youth. However, previous studies are inconsistent on the direction of influence of sedentary behavior on academic performance. Total device-measured sedentary time (ST) was positively associated with academic performance while no association was observed in other studies. These inconsistencies could partly be explained by different measures of academic performance used in the studies, as well as by the fact that the association between ST and academic performance is domain/pattern dependent.In addition to these deleterious health outcomes, sedentary behavior has also been associated with academic performance However, the association between durations of bouts/amounts of breaks of ST in free-living conditions and academic achievement is unclear and has not been explored among adolescents.More so, different patterns of ST in terms of bouts (uninterrupted amount of time during the behavior) and breaks  may impact the academic achievement among children. was associated with both sedentary behavior and academic performance, suggesting it could represent an important mediator of the association between ST patterns and academic performance. The self-concept has been directly related to academic achievement, with a mutual reinforcement between them. However, this potential pathway has not been tested.In addition, the relationship between ST and academic performance is complex and may occur through multiple pathways. In order to inform effective intervention, it is important to understand the potential psychosocial mediators of this relationship. Self-concept — defined as the perception of a person about him/herself —Thus, the aim of this study was to verify the association between ST patterns (bouts and breaks) and academic performance among adolescents aged 10 to 14 years, with emphasis on the mediating role of self-concept on this association. The exclusion criteria were: students who had any physical limitations, or who were being treated for any disease or injury during the study, or who refused to use the accelerometer; aged over 15 years. In addition, the measures were replicated in a sub-sample (n=25), with an interval of one week, to estimate the agreement of the instruments (through Kappa coefficients [k] and intraclass correlation coefficient [ICC]). Both the students and their guardians signed the informed consent to participate. The local Ethics Committee approved all the procedures of this study according to Declaration of Helsinki .This was a school-based cross-sectional study, involving adolescents (both sexes) aged between 10 and 14years old, in the sixth grade of elementary school in public schools in Londrina, Paraná, Brazil. Details of the sample selection process are described in the study of Bueno et al.Academic performance was assessed through semester grades of the following school subjects: Brazilian Portuguese, Mathematics, Science, History and Geography. The grades refer to numerical assessment on a scale of 0–10, in which grades below 6 denote the student’s failure and 10 denotes excellent knowledge and skills. Based on the information of the students’ performance, the averages of the disciplines were calculated, and an mean of the five school subjects was adopted as indicator for the analyses. The academic performance was provided by the education services of the city of Londrina.ActiGraph  GT3X and GT3X-Plus models were used to estimate ST patterns. Participants were instructed to wear the device on the right side of the waist (near the iliac crest) via an elastic belt for seven consecutive days and only remove it during shower, aquatic activities and sleeping time. The accelerometers were configured to collect information in one-second epochs (model GT3X) or at 30 Hz (model GT3X-Plus). After the monitoring period, the equipment was collected and the data stored in the ActiLife computer program (version 6.8.2). Subjects who had at least four complete days of data  registered by the accelerometer were included in the analyses. The criterion of 60 min of consecutive zeros was utilized to determine the non-wear time.-1) in Brazilian adolescents. Bouts were defined as uninterrupted periods in sedentary behavior (drop time=0) with durations of 1–4 minutes, 5–14 minutes and ≥30 minutes. Breaks were defined as the non-sedentary period between two sedentary series. For analytic purposes, total ST and time accumulated in bouts were expressed as percentage values , while breaks were expressed as mean frequency by hour of ST (breaks.hour-1).ST was classified using cut-points developed for ActiGraph vector magnitude counts . The instrument provides, in addition to the total self-concept, six domain scales: behavior, intellectual and school status, physical appearance and personal attributes, anxiety free, popularity, happiness and satisfaction. Participants answered the complete inventory; however, for the present study, the following domains were used: total self-concept (TOT), which reflects the general measure of self-concept, with high results indicating a favorable measure of self-esteem and low results indicating low self-esteem; intellectual and school status (INT), which reflects how children evaluate their skills in relation to intellectual and academic tasks, as well as their satisfaction with the school and their expectations about future achievements; and anxiety-free (FRE), which reflects and evaluates anxiety and behaviors such as worry, nervousness, shyness, sadness and fear. The procedures described in the inventory manual were followed. The self-concept scales presented high agreement (k=0.81–1.0).Self-concept was evaluated through the Piers-Harris II inventory, adapted to the Brazilian Portuguese language by Serassuelo Junior.®, model 813, with precision of 0.1kg, while the stature was determined in a Harpenden Holtain Limited® portable stadiometer with a precision of 0.1cm, according to standardized procedures. Based on this information, body mass index was calculated. Socioeconomic status (SES) was estimated using the Brazilian Association of Research Companies questionnaire, which is composed by questions regarding the purchasing power, with rating ranging from 1 (low SES) to 6 (high SES). The moderate-to-vigorous physical activity (MVPA) was used as a covariate and classified using cut-points recorded by the vector magnitude of the accelerometer (MVPA≥757 counts.15s-1).The body mass was measured on a portable scale of the brand Seca and two continuous indicators were created.The mentally-passive and mentally-active sedentary behavior was used as a covariate, and were assessed through questions about different sedentary behavior, which were asked through the generic questions: “Considering a typical weekday (Monday to Friday), how much time do you spend… (e.g. watch TV)?” and “Considering a typical weekend day (Saturday and Sunday), how much time do you spend… (e.g. watch TV)?”. These questions were asked for watching TV (ICC=0.90), watching DVD (ICC=0.33), using computer for leisure (ICC= 0.72), playing electronic games (ICC=0.54), studying (ICC=0.87) and reading (ICC=0.79), with six possible answers: (a) none, (b) less than 1 hour, (c) between 1 and 2 hours, (d) between 2.01 and 3 hours, (e) between 3.01 and 4 hours, (f) more than 4 hours. Mean time spent in each behavior was computed (e.g. less than 1 hour was transformed to 0.5 hour), and behaviors were divided into mentally-passive  and mentally-active  according to the expected cognitive demand. They were summed was used for the mediation. This method was applied in linear regression models and decomposes the total effect of a variable into direct and indirect effects. This estimation also provides the percentage of explanation by the potential influential factor (mediated percentage). All analyses were conducted in STATA 15.1, adopting p<0.05.Descriptive statistics, with means as well as their respective standard deviations, were used to describe the sample, and differences between sexes were assessed by Mann-Whitney U test. Pearson correlation (separately by sex) was performed to explore the relationship between different self-concept, bouts and breaks of ST. Multiple linear regression was used to test the association between different ST patterns and academic performance regardless of potential confounders. Mediation analysis was conducted to assess the influence of self-concept and efficacy mediators in the association between different sedentary patterns and academic performance. Only the ST patterns that were significant predictors of academic performance were included in the mediation models. The Karlson Holm Breen methodFrom 680 eligible participants, 286 did not provide valid accelerometer data , totalizing a final sample of 394 adolescents. Despite the high level of missing data for device-measured ST, there were no substantial differences between all participants and the final sample for the main variables of the study. The final sample was composed of 394 adolescents (186 boys), with a mean chronological age of 11.9±0.7 years. Characteristics of sample according to sex are presented in The association between different ST patterns (bouts and breaks) and academic performance is presented in The correlation between different patterns of ST and domains of self-concept is showed in The present study analyzed (a) the academic performance between ST patterns (bouts and breaks) and academic performance in adolescents, and (b) the mediating role of self-concept in this association. We found that higher time spent in short bouts and a greater number of breaks in ST were associated with higher academic achievement. On the other hand, bouts ≥30 min were associated with lower academic performance. In addition, the self-concept mediated the associations between ST patterns and academic performance in both sexes, but more consistently in girls. This result reinforced current ST guideline that emphasized that ST patterns and not just the total amount may be important for health outcomes. Moreover, these results may be related to the fact that device measurement does not provide specific contexts of ST, and some sedentary activities, such as reading and homework, may benefit academic achievement. Even there was an association between patterns of ST and academic performance, the magnitude of the associations was generally low, with patterns of ST explaining between 7 and 17% of the variation in the academic performance. Although the proportion is low, it must be highlighted that there are several determinants of academic achievement  and a variation between 7 and 17% can be considerable in this context.Interestingly, while patterns of ST were associated with academic achievement, it was observed that total ST was not, which corroborates previous studies. This pattern of ST tends to be spent in mentally-passive behaviors as TV-viewing, which in turn is associated with lower academic performance and cognition, which would justify the inverse association between longer bouts of ST and academic performance in the present study. This can be explained by time displacement hypothesis that excessive screen time could replace activities involving learning opportunities such as reading books, doing homework, sleeping well, all of which can positively influence academic performance. Moreover, screen time was negatively correlated with functional connectivity in regions related to language, visual processing and cognitive control in adolescents. Despite that, in this study, the ST pattern was associated with academic performance independent of the mentally-passive and mentally-active ST.It has been reported that adolescents accumulated longer bouts of ST especially outside the school period. and contribute to a better academic performance.Therefore, more ST breaks should be encouraged in this age group. Short bouts are closely associated with interruption of ST and consequent muscle contraction would result in increased blood flow, release of growth factors and myocytes, which could increase brain activation, improve brainstorming and memorization, and, consequently, poor academic performance. Most of the studies that investigated the associations between ST and self-concept have analyzed only the physical self-concept. However, intellectual self-concept has shown real importance in academic outcomes in adolescents, as it reflects the adolescents’ perception of their abilities in relation to intellectual and academic tasks, as well as their satisfaction with the school and the expectations they have about future achievements.In addition to the potential biological pathways that could link ST patterns and academic achievement, in this study, the mediator role of self-concept was tested in this association. Although little is known about this, it is possible to speculate that longer ST bouts is associated with reduced self-concept and self-esteem This negative association may be related to increased exposure to social media, social isolation, depression, and cyberbullying. Further studies are needed to clarify how self-concept can affect the academic achievement and other psychological mediators of this association.Also, self-concept partially mediated the association between all types of ST patterns (shorter and longer bouts and breaks) and academic performance among girls and shorter bouts and academic performance among boys. This result indicates a specific path among sexes and that self-concept seems an important variable to consider in order to understand the association between lifestyle behaviors and academic outcomes. In addition, screen time has been associated with negative effects on mental health indicators, such as self-esteem, depressive symptoms, psychological well-being and physical self-concept. However, it may be that different disciplines have different relationships with sedentary behavior, which cannot be verified in the present study, since it was used a single global average of academic performance.Therefore, it was used the global average of five subjects as it includes a wider range of skills, as used in other studies. it can be biased due to its relationship not only to academic skills but also to teacher perception, quality and quantity of academic teaching, family and school environment, and even cultural factors. The level of missing data for device-measured ST was also high; however, there were no substantial differences between the total and final samples. Finally, the analyses by other potential unmeasured confounders as self-esteem and mood were not adjusted. On the other hand, this study has some important strengths. It was adopted a device measurement of the ST (accelerometry), which allowed an analysis of both the total ST and the ST patterns and adjusted the analyses by mentally-passive and mentally-active sedentary behavior. Besides that, the participation of a representative sample of students allows us a robust generalization of our findings to the studied population.The findings in this study should be interpreted in the light of potential limitations. Firstly, due to the cross-sectional design, it was not possible to infer causality and consequence. In addition, although many studies use school grades as a measure of academic performance,In conclusion, longer bouts of ST were associated with poorer academic performance while short bouts and breaks were associated with better academic performance among adolescents. This association is mediated by self-concept, mainly in girls. Furthermore, the patterns of ST were associated with academic performance and total ST was not, confirming the importance of analyzing the ST pattern with academic variables and not just the total ST. Future longitudinal studies should be conducted to confirm prospective association between different ST bouts and academic performance in adolescence.


To investigate the relationship between multimorbidity and health-related quality of life (HRQoL), and explore the effects of functional status and cognitive function on Chinses elderly behind this relationship.The Multivariate logistic regression and Tobit regression models were used to determine the influence of multimorbidity on HRQoL. Bootstrap analysis was used to probe the mediating effects of functional status and the moderating role of cognition on multimorbidity and HRQoL.β = −0.190; 95% confidence interval [CI], −0.232, −0.149; p < 0.001) and the combination of hypertension and stroke  had the greatest influence on HRQoL. Functional status partially mediated the relationship between the number of non-communicable diseases (No. of NCDs) and HRQoL, while cognitive function had a moderating effect not only in the A-path  and but also in the C-path .Results of the 2,887 participants age  ≥ 60  years included in the analysis, 51.69% had chronic diseases. Stroke (Functional status partially mediated the relationship between multimorbidity and HRQoL in older adults. And cognitive function, if declined, may strengthen this relationship. These findings suggested that improving cognitive function and functional status in those who developed multimorbidity could be a viable prevention or treatment strategy to improve HRQoL in elderly patients. Multimorbidity is when multiple chronic diseases occur in the same person. Most studies define it as the presence of two or more chronic conditions . The agiAt present, patients and health care providers are faced with management of long-term sequelae including cognitive and functional impairment . In the Thus, developing more insight into the underlying mechanisms of how multimorbidity cause poor HRQoL will provide new insights into improving public health guidance for patients with multimorbidity. Our study examined the interrelationships between multimorbidity, functional status, cognitive function, and HRQoL. Based on previous research, the following hypotheses were formulated. Hypothesis 1: Functional status mediates the relationship between multimorbidity and HRQoL. Hypothesis 2: Lower cognitive function is likely to elicit functional decline or poorer HRQoL in patients with multimorbidity. Therefore, it is anticipated that multimorbidity is more strongly associated with functional decline and HRQoL when cognitive function is low. The conceptual frame of the moderated mediation model is manifested in The data of our study was derived from The Liyang Study . In thisα = 0.809, Kaiser-Meyer-Olkin value (KMO) = 0.791, Bartlett p < 0.001).The EQ-5D-5L is a universal HRQoL measure from the EuroQoL group which evaluates the current health state of participants. The EQ-5D-5L includes a descriptive system and the EQ visual analog scale (EQ-VAS). The descriptive system consists of five dimensions: mobility (MO), self-care (SC), usual activities (UA), pain/discomfort (PD), and anxiety/depression (AD). Each dimension is described at five levels, corresponding roughly to no, slight, moderate, severe, and extreme problems . The comα = 0.915, KMO = 0.874, Bartlett p < 0.001; α = 0.934, KMO = 0.908, Bartlett p < 0.001; Functional status was assessed using the Lawton IADL and the Katz ADL scales. The Lawton IADL scale is composed of six items: housekeeping, cooking food, shopping, telephone use, taking medications, and handling finances  were used to assess cognitive impairment in the elderly. The AMTs is a 10-item screening questionnaire, including age, time of day, year, place, recognition of people, date of birth, national day, president, counting backwards from 20 to 1, and the recall of an address. Each scale was scored with a maximum score of 10. A score between 0 and 3, 4 and 7, and 8 and above suggests severely impaired function, moderately impaired function, and normal cognitive function, respectively . Smoking status was dichotomized as never smoked (non-smokers), stopped smoking currently (ex-smokers) and currently smoking (current-smokers). Drinking status was classified into currently drinking and no drinking. The number of chronic diseases was the sum of these diseases: hypertension, chronic obstructive pulmonary disease (COPD), stroke, coronary heart disease (CHD), dyslipidemia, asthma, obesity, diabetes, and cancer. And it was grouped into three categories .We used mean ± standard deviation (SD), frequency (percentage), cross-tabulations, and graphical displays for descriptive analysis. Statistical analysis of continuous variables was, respectively, performed using the t-test or one-way analysis of variance (ANOVA), and analysis of categorical variables was performed using the chi-square test. We calculated the prevalence of 36 chronic disease pairs using a random pairwise combination of nine diseases. We then selected the top 10 most prevalent chronic disease pairs to explore their effect on HRQoL. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariate logistic regression and Tobit regression models, respectively. Spearman correlation coefficients were used to analyze the correlations among the main variables. The Harman single factor test was used to conduct a common method bias test. The PROCESS macro for SPSS was used to perform the mediation and moderated mediation hypotheses . Our stu2,887 participants aged ≥60 years who completed the entire survey. The characteristics of the study participants are shown in Of the chronic diseases in our study, dyslipidemia (57.80%) had the highest prevalence, followed by stroke (54.70%), CHD (48.80%), hypertension (40.42%), and COPD 30.80%; . Supplemβ = −0.190; 95% confidence interval [CI], −0.232, −0.149; p < 0.001; Model 1) was the chronic disease that was found to have the greatest impact on HRQoL. Similarly, stroke with hypertension  was the multimorbidity combination that had the greatest influence on HRQoL.Compared with fewer chronic diseases and IADL independence, those who developed more chronic diseases and IADL limitations were more likely to experience problems in each EQ-5D dimension and had a lower HRQoL score . More dir = −0.179, p < 0.01) and HRQoL . HRQoL was positively and significantly correlated with both functional status  and cognitive function  and that the direct predictive effect of the number of chronic diseases on HRQoL was still significant when the mediating variable functional status was added  and HRQoL , indicating that the effect that the number of chronic diseases had on functional status and HRQoL was dependent on the level of cognitive function. The results of cognitive function at specific values suggested that the effect of cognitive function was lower, while the direct effect, indirect effect, total effect, and mediating rate all increased . The modThis current study introduces new insights into the body of research that explores the role of chronic disease pairs on HRQoL and the role of multimorbidity, functional status, and cognitive function in HRQoL. Specifically, hypertension with stroke was found to have the greatest negative impact on HRQoL. We confirmed our expectation that functional status partially mediated the association between the number of chronic diseases and HRQoL. In addition, our results supported the assumption that lower cognitive function may strengthen these associations. These findings help increase our outstanding of the potential mechanism behind worse HRQoL in older adults with multimorbidity and help highlight the interventions targeting these risk factors.We assessed the relationship between common chronic diseases pairs and HRQoL and found that stroke with hypertension had the strongest association with poor HRQoL. In 2016, the global burden disease for risk profiles in the Middle East and North Africa highlight that hypertension was ranked at the first in risk factors for stroke . The incOur results suggested that the effects of multimorbidity on HRQoL were through functional status, which verified our hypothesis 1. The mediation role of functional status in relation to distal variables and in the relationship between multimorbidity and HRQoL is congruent with recent research . A prospOur study found that cognitive function played a moderating role in the direct path of the relationship between multimorbidity and HRQoL, which verified our hypothesis 2. There are some potential mechanisms to explain it. On the one hand, Koyanagi et al. reported that patients with multimorbidity generally had a high risk of mild cognitive impairment . For exaIt is worth noting that our study further found that cognitive function moderated the first half of the mediating model of functional status, which confirmed our hypothesis 2. Namely, multimorbidity in conjunction with lower cognitive function causes functional decline, which consequently contributes to poor HRQoL in older adults. Some literatures may support the potential path mechanisms. Cognitive impairment, was a strong predictor of functional status, and independently mediated functional status difference in traumatic brain injury patients . Loomer Our study is the first to use a moderated mediation analysis to simultaneously probe the effects of cognition and functional status on the relationship between multimorbidity and HRQoL. Previous studies only focused on the effect that multimorbidity had on HRQoL, and few have explored the hazard of common pairs of chronic disease to HRQoL in older adults . UnderstA potential limitation is that this cross-sectional study could not deduce the causal relationship between multimorbidity and functional status, cognitive function, and HRQoL. We will further explore interventions or experimental studies to substantiate these results. Another limitation is that the diagnosis of all NCDs depended on the self-reporting. However, a study indicated that patient-administered questionnaires might be a reliable source of information for epidemiological purposes in a well-defined chronic disease .Our study offers new insights into the relationship between multimorbidity and HRQoL in older adults. Exploring the association between multimorbidity, functional status, cognitive function and HRQoL has shown that functional status partially mediated the relationship between multimorbidity and HRQoL. And cognitive function, if declined, may strengthen this relationship in older adults. These findings suggest that improving cognitive function and functional status in those who developed multimorbidity could be a viable prevention or treatment strategy to improve HRQoL.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by The Life Sciences Ethics Committee of Soochow University (SUDA20211025H02). The patients/participants provided their written informed consent to participate in this study.WH, LZ, LP, LC, and YS designed the study and wrote the protocol. ZF, QH, JC, XC, SL, QH, and NS managed data collection and TL undertook the statistical analysis and wrote the first draft of manuscript. YS and WH gave many valuable comments on the draft and also polished it. All authors contributed to the article and approved the submitted version.This work was supported by the National Natural Science Foundation of China (project number 81973143) and the Priority Academic Program Development of Jiangsu Higher Education Institutions.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


In recent years, muscle strength in children and adolescents has continued to decline, especially in rural areas. Executive function as a higher function of the brain, is closely related to the future achievement of children and adolescents. For this reason, this study analyzed the correlation between muscle strength and executive function in children and adolescents in rural areas of China to better promote the development of muscle strength and executive function.Demographic factors, muscle strength, and executive function were tested in 1,335 children and adolescents in rural China using a three-stage stratified whole-group sampling method. One-way ANOVA and chi-square test were used to compare the differences in executive function among children and adolescents with different muscle strengths. Multiple linear regression analysis and logistic regression analysis were used to analyze the association that exists between muscle strength and executive function.F = 46.592, 45.610, 10.809, 32.068, 24.095, 19.260, 11.501, p < 0.001). Logistic regression analysis was performed using children and adolescents with muscle strength index >P80 as the control group. The results showed that the risk of 1back dysfunction was higher  in children and adolescents with muscle strength index <P20 (p < 0.05). The risk of 2back dysfunction was higher in children and adolescents with a muscle strength index <P20  (p < 0.01). Compared with children and adolescents with muscle strength index >P80. The muscle strength index <P20 group had a higher risk of cognitive flexibility dysfunction  (p < 0.05).When comparing the inconsistently, congruent, 1back, 2back, conversion, size parity, and cognitive flexibility response times of children and adolescents with different muscle strength indexes in rural China, the differences were statistically significant (There is a association between muscle strength and executive function in children and adolescents in rural areas of China. Those with higher muscle strength have shorter executive function reaction times and are at lower risk of developing executive dysfunction. Future measures should be taken to improve muscle strength and executive function levels in children and adolescents in rural areas to promote healthy physical and mental development. Muscle strength is an important component of physical fitness . InadequExecutive function refers to the top-down control of behavior through the use of its core components, such as inhibit function, refresh memory function , and cognitive flexibility . Normal A further review of previous studies revealed some shortcomings in this area of research. First, fewer studies have been conducted using comprehensive muscle indices. Muscle strength tests are an important part of physical fitness tests in many countries and regions in the world today. The most commonly used simple muscle strength test indices in Chinese children and adolescents’ physical fitness tests are grip strength, pull-ups, standing long jump, and sit-ups. Grip strength and pull-ups are measures of upper limb muscle strength, standing long jump is a common indicator of lower limb body muscle strength, and sit-ups are valid indicators in abdominal strength tests . HoweverIn view of the current status of previous studies, our study tested upper limb, abdominal, and lower limb muscle strength in children and adolescents from rural areas of China and calculated muscle strength indices according to age and gender to provide a comprehensive picture of the muscle strength levels of children and adolescents. Executive function was also tested to analyze the association that exists between muscle strength and executive function. To our knowledge, this is the first study in China to explore the association between muscle strength and executive function in rural children and adolescents. Our study provides a reference and help for the improvement of muscle strength and executive function in Chinese children and adolescents.We used a three-stage stratified whole-group sampling method to draw subjects. In the first stage, rural areas in Anhui, Henan, Jiangxi, and Hubei in the central and western regions of China were used as the provinces for testing. In the second stage, three junior high schools in rural areas were selected in each province. In the third stage, in each school, one teaching class in each grade from the first to the third grade was randomly selected in whole groups, and the students in the class who met the requirements were used as test subjects for this study. Specific inclusion criteria were: junior high school students enrolled in school, family domicile and residence in a rural area, physical ability to participate in tests of muscle strength and executive function, and voluntary acceptance of the survey and signing of an informed consent form. Ultimately, a total of 1,387 middle school students aged 13–15 years from 36 classes in 12 rural schools were sampled for our study, and after excluding 52 data with missing key demographic information and failed executive function tests after the survey, a total of 1,335 valid data were retrieved. The average age of the participants was (14.15 ± 0.84) years. The specific sampling procedure is described in Written informed consent was obtained from the participants themselves, their parents or guardians for the investigation of our study. The study was approved by the Human Ethics Committee of Huanghuai University (202105012). The study complied with the ethical procedures and requirements.Our study muscle strength tests include grip, pull up, sit ups, standing long jump a total of four indicators. Both boys and girls tested grip, standing long jump boys tested pull up and girls tested sit ups. The test results were standardized according to gender and age group. The standardized results of each subject were summed to obtain the muscle strength index (MSI), which reflects the overall muscle strength level of the subjects. Grip, pull up, sit ups and standing long jump were tested according to the testing instruments and methods required by the China National Student Physical Fitness Survey. Grip was accurate to 0.1 kg, pull up and sit ups were accurate to 1 time, and standing long jump was accurate to 0.1 cm. The grip strength test requires the arm to drop naturally and the strong side of the arm is used for the test. The standing long jump is performed by using a standing jump.We studied tests of executive functions including inhibit function, refresh memory function , and cognitive flexibility the test methods for each specific executive function are described in a previous study . The tes2. MVPA was investigated by the subjects based on their average daily MVPA in the past 7 days. MVPA time included fast running, heavy lifting, ball games, ice skating, skiing, etc. when they felt out of breath. The average daily MVPA time in min/d was calculated based on the number and average time of MVPA performed per day over the past 7 days.The covariates in our study included age, sex, only child, father’s education level, mother’s education level, breakfast, dairy products, duration of sleep, BMI, moderate and vigorous physical activity (MVPA). The father’s education level and mother’s education level were divided into two groups: junior high school and below, high school and above. Breakfast and dairy products were divided into two groups: ≤3times/week, ≥ 4times/week. Duration of sleep was divided into two groups: ≥8 h/day, <8 h/day. The body mass index (BMI) was calculated based on the tested height and weight, and the formula was weight (kg)/height (m)Our research survey consisted of trained and tested teachers and graduate students divided into four groups that entered different provincial schools at the same time to conduct the survey. A uniform instructional language was used to explain the requirements of the survey and test to the participants before the survey. Questionnaires were distributed on the spot and filled out on the spot, and questions were answered promptly in the process of filling them out. The questionnaires were collected on the spot after completion. The tests of executive functions were explained and demonstrated by the instructor and then tested by the participants on the computer. The tests were filled out using anonymous numbers.Comparison of different muscle strength index classifications of children and adolescents in rural areas of China was performed using one-way methodological analysis (continuous variables) and chi-square test (count data). Count data were expressed as percentages and continuous variables were expressed as means and standard deviations (M ± SD). The comparison of executive function response times of children and adolescents with different muscle strength index was performed by one-way ANOVA. The association analysis between muscle strength index and executive function was studied by multiple linear regression analysis. Muscle strength index <P20 was used as the reference group for the analysis. Model 1 was the unadjusted variable, model 2 adjusted for age, sex, only child, father’s education level, and mother’s education level. Model 3 was adjusted for breakfast, dairy products, duration of sleep, BMI, and MVPA on the basis of Model 2. In order to further analyze the association between muscle strength index and executive function, we also conducted logistic regression analysis. Based on the standard deviation of the mean values of each subfunction of executive function by age and gender, children and adolescents with a test response higher than 1 standard deviation were defined as having executive dysfunction, and this was used to classify the presence or absence of executive dysfunction. Logistic regression analysis was performed with the muscle strength index >P80 group as the reference group, adjusted for different variables. The data were analyzed using SPSS25.0  software, with α = 0.05 as the level of the two-sided test.We investigated demographic variables, grip strength, sit-ups, pull-ups, standing long jump and executive function in 1,335  children and adolescents aged 13–15 years in rural areas of China with a mean age of (14.15 ± 0.84) years.2 = 7.638, 54.800, p < 0.05). In terms of BMI and MVPA, the differences were statistically significant when comparing different muscle strength index classifications   .F = 46.592, 45.610, 10.809, 32.068, 24.095, 19.260, 11.501, p < 0.001). Overall, children and adolescents with muscle strength index >P80 had shorter reaction times, and those with muscle strength index <P20 had longer reaction times  (After adjusting for relevant confounding variables (Model3), the results of multiple linear regression analysis showed that compared to those with muscle strength index <P20, those with muscle strength index >P80 inconsistently, congruent, 1back, 2back, and conversion, size parity, and cognitive flexibility reaction times were reduced by 51.243, 50.653, 100.527, 185.766, 105.641, 39.062, and 66.579 ms, respectively, with statistically significant differences (< 0.001) .p < 0.05). The risk of 2back dysfunction was higher in children and adolescents with a muscle strength index <P20  (p < 0.01). Compared with children and adolescents with muscle strength index >P80, the muscle strength index <P20 group had a higher risk of cognitive flexibility dysfunction  (p < 0.05) (After adjusting for relevant confounding variables (Model3), logistic regression analysis was performed using children and adolescents with muscle strength index >P80 as the control group. The results showed that the risk of 1back dysfunction was higher  in children and adolescents with muscle strength index <P20 ( < 0.05) .2, whole-body muscle strength test results were: grip (29.98 ± 9.06) kg, pull up (2.91 ± 2.93) times, sit ups (29.80 ± 8.57), standing long jump (173.91 ± 31.48) cm.The purpose of this study was to investigate and analyze the association between muscle strength and executive function in children and adolescents in rural areas of China, in order to better promote the development of muscle strength and executive function. The association between muscle strength and executive function existed in children and adolescents in rural areas of China. Those with higher muscle strength had shorter executive function reaction times and were at lower risk of developing executive dysfunction. Our study included 1,335 children and adolescents aged 13–15 years from four different provinces in rural areas of China. The results of our study showed that the mean BMI (19.98 ± 2.48) kg/mFurther analysis of the results of the muscle strength test revealed that the results of the grip test for rural children and adolescents in China were significantly lower than the average for children and adolescents aged 13–15 years in the United States (60.9 kg) . The reaOne-way ANOVA and multiple linear regression analyses revealed that children and adolescents with high muscle strength had shorter executive function reaction times, i.e., higher levels of executive function. Our results are consistent with the findings of previous studies that muscle strength and executive function are correlated . WhereasFurther logistic regression analysis also showed a strong association between poorer muscle strength and a higher prevalence of executive dysfunction. Previous studies have shown that high levels of muscle strength may indirectly improve health through beneficial effects on body composition and aerobic performance . Muscle Several strengths exist in our study. On the one hand, our study is the first to investigate and analyze the association between muscle strength and executive function in children and adolescents in rural areas of China, which provides a reference for healthy development of children and adolescents in rural areas. In addition, our study uses a comprehensive muscle index reflecting muscle strength for analysis, which provides a more comprehensive response to the muscle strength level of children and adolescents. However, our study also has some limitations. First, the sample size of our study was relatively low, and the area investigated in the study was only in rural areas of four provinces in China, and the area studied was somewhat limited. Second, the control of covariates in our study was limited, such as the lack of investigation of cardiorespiratory endurance, sugary drinks, and smoking, and these deficiencies are to be remedied in future studies.There is a close association between muscle strength and executive function in children and adolescents in rural areas of China. Children and adolescents with higher muscle strength in rural areas of China had shorter executive function reaction times and lower risk of executive function disorders. Based on our findings, effective measures should be taken in the future to improve muscle strength and executive function levels of children and adolescents in rural areas of China. Such as securing teaching time for physical education classes, securing time for extracurricular activities, strengthening health education, and conducting executive function training in order to promote the healthy physical and mental development of children and adolescents in rural areas of China. In addition, improving muscle strength and executive function in children and adolescents is a long-term process. It requires concerted efforts and joint efforts of families, schools and children and adolescents themselves to better achieve the improvement results.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved the Human Ethics Committee of Huanghuai University (202105012). Written informed consent to participate in this study was provided by the participants or their legal guardian/next of kin.QZ, XH, and YW: conceptualization. QZ: data curation, funding acquisition, and visualization. QZ and XH: formal analysis, software, writing—original draft, and writing—review and editing. YW: investigation, methodology, validation, and resources. XH and YW: project administration and supervision. All authors have read and agreed to the published version of the manuscript.


The relationship between the new obesity index weight-adjusted-waist index (WWI) and hyperuricemia is unclear. We aimed to explore the association of the WWI and hyperuricemia among the hypertensive population.A total of 14,078 hypertension participants with complete data were included in our study. WWI was calculated by waist circumference divided by the square root of weight. Specifically, men with 420 μmol/L and women with 360 μmol/L were considered to have hyperuricemia.P-interactions >.05).The prevalence of hyperuricemia was 61.1% in men and 51.4% in women. On the whole, multivariate logistic regression analyses found that there was a linear positive correlation of WWI with hyperuricemia in both men  and women . Subgroup analysis found that the relationship between WWI and hyperuricemia was stable in stratified subgroups (all WWI showed a positive association with hyperuricemia among hypertension patients. The incidence rate and prevalence of hyperuricemia are on the rise worldwide. Based on the results of two nationally representative cross-sectional surveys conducted in China, the prevalence of hyperuricemia among Chinese adults has risen from 11.1% in 2015–2016 to 14.0% in 2018–2019 . HyperurUric acid is the final metabolite of human purine compounds and is mainly excreted by the kidney. Hyperuricemia results from the body producing too much uric acid or excreting it insufficiently . RelevanAs we all know, obesity is a risk element for hypertension . PreviouThe data analyzed in this study was derived from the China Hypertension Registry Study (Registration number: ChiCTR1800017274). The research design and methods have been published in previous articles . Brieflyn = 34) and had data missing (n = 156). Finally, 14,078 participants were enrolled in our analysis , medication information, and medical history, was gathered by questionnaire used by the research staff. After having a rest for 10 minutes, an electronic sphygmomanometer  was used to acquire the participants’ information on blood pressure; the measurement was repeated three times with an interval of 1 minute. The mean value of three independent measurements for SBP and DBP were taken for analysis. Blood samples were obtained by venipuncture at baseline and processed and analyzed at Biaojia Biotechnology, sited in Shenzhen in Guangdong Province, China, for homocysteine, serum total cholesterol, triglyceride, uric acid, high density lipoprotein, low density lipoprotein, and eGFR.Anthropometric indices, such as height, weight, and waist circumference (WC), were also collected. The height was obtained by using a fixed vertical ruler and standard right angle device on participants without shoes. Weight was also gained without shoes. WC was measured when standing with a tape measure at the end of expiration. BMI was calculated by dividing body weight (kg) by the square of height (m). WWI was calculated as WC (cm) divided by the square root of weight (kg) .Based on previous studies on obesity and hyperuricemia, we divided WWI into four groups according to its quartile. WWI quartiles in males were defined as follows: <10.4 cm/√kg (Q 1), ≥10.4 and <10.8cm/√kg (Q 2), ≥10.8 and <11.2 cm/√kg (Q 3), and ≥11.2 cm/√kg (Q 4). WWI quartiles in females were <10.8 cm/√kg (Q 1), ≥10.8 and <11.3cm/√kg (Q 2), ≥11.3 and <11.8 cm/√kg (Q 3), and ≥11.8 cm/√kg (Q 4).The level of SUA in the present study was measured by automated clinical analyzers (Beckman Coulter). Specifically, men with 420 μmol/L and women with 360 μmol/L were considered to have hyperuricemia , 26.P trend value. We constructed three models to evaluate the independent correlation between WWI with SUA and hyperuricemia. Model 1 was a crude model, unadjusted. Model 2 was adjusted for age, current smoking, and current drinking. Model 3 was adjusted for age, current smoking, current drinking, heart rate, stroke, Diabetes mellitus, coronary heart disease, antihypertensive drugs, lipid-lowering drugs, glucose-lowering drugs, homocysteine, serum total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, and eGFR. All the covariates were selected on the basis of their clinical importance, statistical significance in the univariable analyses, and the estimated variables change of at least 10% of potential confounding effects . The Chi-square (x2) tests or ANOVA were used to evaluate the differences among the groups by WWI quartiles. Multivariate logistic regression was used to evaluate the OR and 95% CI of the correlation between WWI and hyperuricemia. The fitted smoothing curve and generalized additive model were also used to examine the dose-response correlation of WWI with SUA and the risk of hyperuricemia. At the same time, we converted WWI into classification variables and calculated the  effects . Moreovewww.empowerstats.com) were used to perform all analyses. A two-tailed P <.05 was deemed statistically significant.The statistical package R  and Empower (R) (The quartiles of the WWI show participants’ baseline characteristics in P for trend <.001). Among women, also taking the lowest quartile (Q1) as the reference group, the incidence of hyperuricemia raised with the increase of WWI, Q2 , Q3 , and Q4  respectively (P for trend <.001). The positive correlation between WWI with SUA both in men and women are shown in We also used the fitted smoothing curve and generalized additive model to confirm the linearly positive association between WWI with SUA and hyperuricemia for men and women .To confirm whether the correlation of WWI with hyperuricemia is stable in different subgroups, subgroup analyses were performed 3. The rIn this cross-sectional study based on a large sample size, we examined the correlation of WWI, a new obesity index, with hyperuricemia in people with hypertension for the first time. In the fully adjusted model, we found a positive correlation of WWI with SUA level and the risk of hyperuricemia in both men and women, and these results were stable in subgroup analyses. Even after adjusting for BMI and when BMI was well-controlled , the results remain significant.2), the prevalence of hyperuricemia in overweight people (BMI: 23–27.5kg/m2) was about 2.98 times more and that in obese people (BMI ≥ 27.5kg/m2) was 5.96 times more. However, another study, also aimed at the Chinese population, indicated that there was a short-of-significant correlation of BMI with hyperuricemia  and 4.332 , respectively  and lipid accumulation product (LAP) index highest quartile groups’ OR were 2.049 ; that is, WWI was significantly correlated with the risk of hypertension (2).WWI is a new obesity anthropometric index  proposedrtension . HoweverThe potential mechanism of the positive correlation between WWI and hyperuricemia can be explained by the role of abdominal fat as a marker of ectopic fat excess. The increase of WWI may reflect the dysfunction of adipose tissue, thereby causing an increase in uric acid secretion and inhibiting uric acid excretion. First, excessive fat deposition in obese patients will act on the liver, affect the metabolism of purine , and raiThe main advantages of our study were the large population-based sample size, including a large number of patients with hypertension, and subgroup analysis to test the robustness of the results. However, this study also has some limitations that need attention. First, this study was a cross-sectional design, so we were unable to determine the causal relationship correlation of WWI with hyperuricemia. Second, although we adjusted for possible covariates, the potential residual confounding factors may still exist. Third, recent epidemiological studies show that dietary factors are also a cause of hyperuricemia ; howeverIn the hypertensive population, we found an independent positive relationship of WWI and the occurrence of hyperuricemia risk events. The results suggest that the WWI index can be used as a simple and effective intervention indicator and may have preventive value for the hyperuricemia population in southern China.The original contributions presented in the study are included in the article/All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The protocol was approved by the ethics committee of the Institute of biomedical research of Anhui Medical University. All participants provided written informed consent before entering the study.PZ wrote the manuscript. PZ, YX, and YS participated in the literature search, data analysis, and data interpretation. WS extracted and collected data. XS, GQ, CD, JL, WZ, CY, TW, and LZ conceived of the study and participated in its design and coordination. XC and HB participated in the study design and provided critical revision. All authors read and approved the final manuscript.This work was supported by the Jiangxi Science and Technology Innovation Platform Project (20165BCD41005), Jiangxi Provincial Natural Science Foundation (20212ACB206019), Jiangxi Science and Technology Innovation Base Construction Project (20221ZDG02010), Jiangxi Provincial Health Commission Science and Technology Project (202210495), Fund project of the Second Affiliated Hospital of Nanchang University .Thanks to all the investigators and subjects who participated in the China Hypertension Registry Study.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Early identification of children at risk of learning disorders (LD) may mitigate the adverse effects of delayed intervention by guiding children to receive preventive services at an earlier age. However, there is no assessment tool for the early identification of children at risk of LD in Mainland China. Therefore, this study aimed to create a Chinese version of the Preschool Learning Skills Scale and investigate its validity and reliability.Firstly, a pilot scale was designed based on literature review and expert review. Secondly, a pre-survey of the pilot scale was conducted. In phase 3, a formal survey was carried out to test the reliability and validity of the scale by involving 2,677 preschool children from 7 kindergartens. Data were collected using a checklist for demographic characteristics, the preschool learning skills scale, the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P), and Conners' Rating Scales.r = 0.641, P < 0.001) and the cognitive problems factor of Conners' Rating Scales . The model had a good fit . Multigroup confirmatory factor analysis supported the structural and measurement invariance on the preschool learning skills scale across gender and grade.The final scale included 38 items under seven factors. The reliability and validity tests confirmed that the Cronbach's alpha, split-half reliability, and test–retest reliability coefficients of the scale were 0.946, 0.888, and 0.941, respectively. The Spearman correlations of factor-total score ranged from 0.685 to 0.876. The results of criterion-related validity showed a direct and significant association between the preschool learning skills scale with the BRIEF-P (The developed preschool learning skills scale has good reliability and validity, indicating that the scale can be used to identify preschool children at risk of LD and can be recommended for use in clinical research and practice. Specific learning disorder (LD) is a complex neurodevelopmental disorder . AccordiStudies have shown that the prevalence of LD in the general population ranges from 3 to 12% depending on factors such as different assessment tools, boundaries of measurement, cultural background, gender, age, etc. –8. The aResearchers have developed many behavior checklists for the screening of LD, which are primarily suitable for school-age children, mainly focusing on academic skills such as reading, writing, and arithmetic , 14. In However, preschool age is a crucial period for early identification and intervention of LD. In kindergarten, children with mathematics disorders already have deficits in comparing non-symbolic and symbolic Arabic numbers . SeveralThus, this study aimed to construct a brief, easy-to-use scale to specify the characteristics of LD for parents from mainland China to identify preschoolers at risk of LD at an early stage and to test the validity and reliability of the scale.The Preschool Learning Skills Scale  aimed toThe development of the preschool learning skills scale for parents of preschoolers in mainland China followed many stages .In the first stage, based on an extensive review of relevant literature and published questionnaires, as well as on consultations with parents of children with LD, and specialists and teachers who specialize in LD, the primary cognitive and behavioral manifestations of children with LD in the preschool years were determined to identify key components related to LD risk. Finally, a total of 7 dimensions with 71 items were generated from the item pool, which forms the index system framework of the scale, classified into seven categories: attention, memorization, visual perception, auditory perception, motor coordination, verbal competence, and mathematical concept.n = 5, including the first and corresponding authors) reviewed the bank of items to classify those contents into each key theme to identify gaps and overlaps between items and to figure out the suitability of items for parents of preschool children. The scale was adapted and revised with inappropriate items removed. Finally, 55 items were selected to form the first draft of the preschool learning skills scale. All items were rated on a 5-point Likert scale ranging from never to always.In phase 2, a panel of experts in developmental–behavioral pediatrics, psychology, pedagogy, public health, and clinical evaluation (n = 8) to determine whether the items comprehensively reflected the key behaviors that could develop into LD in preschool-aged children to establish content validity. Then, the questionnaire was put to an experimental test to render certain that the parents of preschoolers (n = 20) understood the items as intended. Furthermore, based on the experimental testing results, the questionnaire was refined by modifying the items which were difficult to understand, had semantic ambiguity, and were prone to ambiguity due to the experimental testing results.In phase 3, to ensure the scale's content validity, the questionnaire was reviewed and refined again by a panel of experts  and a demographic survey.Through the pre-survey, 55 items were scientifically refined in the following methods: critical ratio method, frequency distribution analysis, variation coefficient (CV) method, correlation analysis, Cronbach's alpha coefficient method, and exploratory factor analysis . ConsideA total of 2,677 preschool children were selected from 7 kindergartens in Nanjing. Exclusion and inclusion criteria were the same as those for the pre-test of the study. The parents electronically signed the consent document and completed the questionnaire survey within 3 days of receipt of the survey (first assessment T1). In addition to the 38-item learning skills scale  and a demographic survey, 600 parents were randomly selected to extra complete the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P) and Conners' Rating Scales (Conners 3-P) for assessment of criterion-related validity.The reliability of the scale was assessed using Cronbach's alpha, split-half correlation, and test–retest. A random sample of the parents filled in the preschool learning skills scale 2 weeks after the first survey (T2) to assess test–retest reliability.n = 1,540) were used for the exploratory factor analysis (EFA), and data from three kindergartens  for the confirmatory factor analysis (CFA). The EFA was performed by IBM SPSS Statistics 26.0. The suitability of the data for factorization was evaluated by the value for the Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy and Bartlett's test of sphericity (preferably significant) (via iterative Maximum Likelihood with Promax Rotation to extract the factors due to the correlation of the factors (2/df ) values, with values <5.0 deemed acceptable; the root-mean-square error of approximation (RMSEA); the root-mean-square residual (RMR) <0.05; the comparative fit index (CFI); the Tucker-Lewis index (TLI); and the incremental fit index (IFI) >0.9  >0.9 , 29. Then = 1,137), we conducted a multigroup confirmatory factor analysis to examine the measurement invariance of the seven-factor structure across gender: boys vs. girls. Measurement invariance was also tested across age groups: Group 1 (Junior Class of kindergarten), Group 2 (Middle Class of kindergarten), and Group 3 (Senior Class of kindergarten). The measurement invariance was evaluated using the following fit indices: the change in chi-square values (Δχ2) and the fit indices   , 31. Meand ΔCFI) .n = 2,090, 78.07%).As shown in P < 0.001, indicating that exploratory factor analysis was appropriate.The appropriateness of factor analysis was measured by The Kaiser–Meyer–Olkin (KMO) measure of the sampling adequacy and the Bartlett test of sphericity. The results showed KMO = 0.966 and Bartlett significance Seven factors were extracted from the preschool learning skills scale by the EFA see . The facThe reliability results of PLSS are shown in r = 0.641, P < 0.001) and the cognitive problems factor of Conners' Rating Scales .The Spearman correlations of the factor-total score ranged from 0.685 to 0.876. The Spearman correlations of the interfactor varied between 0.417 and 0.716 ; the cor2/df = 3.489, the RMSEA was 0.047, the RMR was 0.024, the CFI was 0.912, the TLI was 0.900, and the IFI was 0.912. These results indicated that the goodness-of-fit index of the model was valid. The standardized regression coefficients of each item of the preschool learning skills scale ranged from 0.490 to 0.747. These values were more than 0.4 (P < 0.001), which indicated that the items corresponding to each latent variable were highly representative. The discriminant validity of the preschool learning skills scale was evaluated using correlation coefficients among seven factors (P < 0.001). The correlation coefficients were all less than the square root of the corresponding AVE. These results were satisfactory and indicated adequate discriminant validity in the study.than 0.4  and CR v factors . CorrelaTo examine the measurement invariance of the preschool learning skills scale across both gender and grade, we used a multigroup confirmatory factor analysis approach, which assesses the measurement invariance across two or more groups by using a series of increasingly stringent, nested models.Subsequently, measurement invariance across grades was examined. As Learning disorders refers to a group of disorders characterized by significant difficulties in listening, reading, speaking, writing, attention, memorization, and coordination. These difficulties range from mild to severe. Researchers have made consistent efforts to identify and intervene early to ensure that children receive assistance prior to having poor learning experiences and prevent other problems that may affect their learning abilities , 18, 21.Different manifestations of LD can be seen at various ages and as a result of varying learning demands. Delays in speech and language development, numerical and symbolic concepts, motor coordination, and auditory and visual perception are early indicators of children who may have LD –35. ThesIn this study, we first defined the connotation and characteristics of LD by reviewing the related researches. A literature search was performed using the following terms: “learning ability,” “LD,” “dyslexia,” “mathematical disorder,” “kindergarten,” and “preschool children” in PubMed, EMBASE, Web of Science, and MEDLINE, CNKI, and Wanfang databases. In the retrieved literature, the behavioral manifestations and characteristics of children with LD were perused, as well as related guidelines, expert consensus, systematic evaluation, and original research on screening and diagnosis of LD. Then, we summarized and compared the scales or tools for early identification of LD in domestic and foreign studies, such as the Pupil Rating Scale Revised (PRS) questionnaire, Hong Kong Learning Behavior checklist for Preschool Children (Parent Version), East Asia-Pacific Early Child Development Scales, South African Early Learning Outcomes Measure, etc., to clear and definite the methods, structures, and indicators of early identification of LD. Finally, we studied the localization theory of early identification for LD in Mainland China. Through in-depth interviews with experts in child psychology, developmental-behavioral pediatrics, teachers, and parents of children with LD, their attitudes, views, and experiences toward the early identification of LD in the preschool age were summarized. From these, the preschool learning skills scale, which is the first scale for early identification of preschoolers at risk of LD in Mainland China, establishes the item pool for the initial experimental checklist based on the theoretical framework of the following: attention, memorization, visual perception, auditory perception, motor coordination, verbal competence, and mathematical concept.via exploratory and confirmatory factor analysis. After establishing a robust factor structure within a sample, it is essential to know whether this factor structure is also applicable across samples or groups, as this “invariance” is the only condition that can be allowed to investigate group differences, for instance, between different genders and ages, and so on (P < 0.001) and three grades of kindergarten (P < 0.001), it is crucial to establish measurement invariance across gender and grade to elucidate if the preschool learning skills scale's sensitivity can identify preschool children at risk of LD. The results of the multigroup confirmatory factor analysis indicated a reasonable level of structural invariance and measurement invariance across gender and grade of the preschool learning skills scale. Therefore, as a screening scale, the preschool learning skills scale was considered to provide information on the cognitive weaknesses of LD and could be used to screen for children at risk of LD for further assessment or preventive interventions.Our research conducted psychometric evaluation through the critical ratio method, frequency distribution analysis, variation coefficient (CV) method, correlation analysis, Cronbach's alpha coefficient method, and exploratory factor analysis, suggesting the retention of 38 items to be included in the revised checklist. To evaluate the reliability and validity of the 38-item preschool learning skills scale, we conducted a questionnaire survey among 2,677 preschool children from 7 kindergartens. Overall, our results demonstrate that the developed preschool learning skills scale had good reliability and validity, and showed an excellent fit of the seven derived factors nd so on . Given tNevertheless, further research is needed. Since this study relied on parent reports, it will be necessary for future research to explore the correspondence between parental reports with other reports (such as teachers) and observations of clinicians or educational psychologists , 38. MorDespite these limitations, the preschool learning skills scale has the potential to be a reliable measure that provides a scientific basis for early identification and intervention of LD in preschool age.To our knowledge, this is the first study to develop a brief, easy-to-use questionnaire to describe the characteristics of LD in preschool-age for early identification of children at risk of LD. Overall, as an instrument, the developed preschool learning skills scale has good reliability and validity, which indicates that the scale can be used for the early identification of preschool children at risk of LD and can be recommended for use in clinical research and practice. However, study findings are limited to the early identification of preschool children at the risk of LD, and the evaluation of the predictability of the scale is needed. Further research is needed to evaluate the validity of the scale by examining the relationship between the preschool learning skills scale and objective predictors of LD, such as rapid automatized naming, phonological awareness, letter knowledge, and short-term verbal memorization.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the Medical Ethics Committee in the Nanjing Maternity and Child Health Care Hospital. Written informed consent to participate in this study was provided by the participants' legal guardian/next of kin.MY: conceptualization, methodology, and writing—original draft preparation. JW: data curation, formal analysis, and writing—original draft preparation. PL: methodology and data curation. YX: validation. YG: data collection. LZ: data collection and validation. NS: language proofreading. YL: funding acquisition. DY: methodology. QH: supervision and writing—reviewing and editing. XC: funding acquisition and writing—reviewing and editing. All authors reviewed the manuscript. All authors contributed to the article and approved the submitted version.This work was supported by the High Level Talents of Jiangsu Province (Project No. WSN-165/WSW-125), the Key Medical Science and Technology Development Projects in Nanjing (Project No. ZKX 18044), the Medical Science and Technology Development Projects in Nanjing (Project No. YKK 19115), Specialized Disease Cohort Study of Nanjing Medical University (Project No. NMUC2018014A), the Key Young Medical Talents of Jiangsu Province (Project No. QNRC2016100), and the National Natural Science Foundation of China (Project No. 32000759).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Growing evidence has shown that the antioxidant diet is a protective factor against depression. However, the relationship between the Composite Dietary Antioxidant Index (CDAI), an important measure of antioxidant diet, and depression has received little attention. Therefore, we investigated the relationship between CDAI and depression through a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018.The association between CDAI and depression was investigated using a weighted multiple logistic regression model with subgroup analysis. Non-linear correlations were explored using fitted smoothing curves. And we used a recursive method to figure out the turning point and build a weighted two-piece linear regression model.In the multivariate logistic regression model with full adjustment for confounding variables, the ORs (95% CI) for the association between CDAI and depression were 0.83 . Moreover, a non-linear association was found, with 0.16 being the inflection point. Before the inflection point, each unit increase in CDAI was associated with a 30% decrease in the risk of depression. After the inflection point, the risk of depression was found to be reduced by 11% for each unit increase. None of the interactions in all subgroup analyses were statistically significant.Our study highlighted a negative non-linear association between CDAI and depression in a nationally representative sample of US adults. Further clinical and basic research is needed to explore their association better. Depression is a complex group of disorders with severe dysfunction, and prolonged depression can easily lead to adverse events such as cardiovascular disease (CVD), diabetes, and stroke . AccordiOxidative stress is an imbalance between reactive oxygen species production or exposure and antioxidant defense, favoring the production of reactive oxygen species in a complex biological process . NumerouThe Composite Dietary Antioxidant Index (CDAI) is a valid and reliable nutritional tool that assesses a person's diet's overall antioxidant characteristics, which is a summary score of multiple dietary antioxidants including vitamins A, C, and E, manganese, selenium, and zinc . A previThe NHANES is an ongoing survey conducted by the Center for Disease Control and Prevention (CDC) to collect information on the health, nutrition, and sociology of the US family population. After a strict inclusion of exclusion, we included six cycles with 26,026 adult participants . To seleThe NHANES collected participants' food intake on two consecutive days via a 24-h dietary recall interview. The first dietary recall was conducted in person, and the second dietary recall proceeded 3–10 days later over the telephone. Average daily intakes were calculated from 2 days dietary recall data. The CDAI was calculated for all subjects using the measurement method recommended by Wright , with reThe 9-item Patient Health Questionnaire (PHQ-9) was used to assess depressive symptoms in the 2 weeks before the survey. The PHQ-9 questionnaire is designed to assess each of the nine diagnostic criteria for major depression listed in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition . The score for each question was defined as 0 , 1 (a few days), 2 , and 3 (nearly every day), with a total scale score range of 0–27 . IndividDemographic, smoking status, vigorous recreational activity, and self-reported health data were obtained using the Computer Assisted Personal Interviewing system. Demographic variables included age, sex, race/ethnicity, education level, marriage, and income to poverty ratio. The income to poverty ratio is calculated relative to the Department of Health and Human Services poverty guidelines for household income and is categorized as ≤ 130% or >130% . The vighttp://www.empowerstats.com) were used to conduct statistical analyses. P-values < 0.05 were considered statistically significant.As required by the NCHS, we weighted the data in our analysis. Participants were separated into two groups based on whether they had depression. We presented continuous variables as means  and categorical variables as quantities (percentages) in the baseline characteristics of the study population. The baseline characteristics were compared using the weighted linear regression for continuous variables and the weighted chi-square test for categorical variables. To test the relationship between CDAI and depression, we used multiple regression equations, built crude and adjusted models, and carried out tests for linear trends to ascertain the relationships consistency. Generalized additive models were then performed to assess whether there were any non-linear correlations. After detecting non-linearity, the turning point was calculated using a recursive algorithm, and then a two-piecewise linear regression model was constructed. We performed subgroup analyses and interactions to explore whether there were other relevant risk factors that might influence the association of CDAI with depression. R (version 3.5.3) and the EmpowerStats software , and the percentage of women in the depressed population was 64.54%, higher than the 35.46% of men. Income to poverty ratio, uric acid, energy, and vigorous recreational activity were lower in depressed patients than in non-depressed patients. In terms of smoking status, 60.43% of depressed patients had a history of smoking or were currently smoking .Three models were constructed to examine the relationship between CDAI and depression in this study. Model 1, no covariate was adjusted; Model 2 was adjusted for age, gender, and race. Model 3 added to model 2 the education level, income to poverty ratio, marital status, smoking status, vigorous recreational activity, BMI, CRP, stroke, cancer, diabetes, CVD, energy, and uric acid as covariates. In the crude model, the ORs (95% CI) were 0.77 , which indicated that the risk of depression was reduced by 23% for every unit rise in CDAI. The risk of depression dropped by 20% [0.80 ] for each unit rise in CDAI in the model only adjusted for demographic data (model 2). In the fully adjusted model (model 3), the risk of depression decreased by 17% for each unit increase in CDAI [0.83 ] . For theP for non-linearity = 0.004)  . Further= 0.004) . In the = 0.004) , 4. . FurtheWe performed subgroup analyses to explore the potential association between CDAI and the risk of depression in different populations based on education level, marital status, vigorous recreational activities, smoking status, stroke, diabetes, cancer, and CVD. The results showed that CDAI did not show statistically significant differences in reducing the risk of depression in people with a history of stroke, diabetes, CVD, cancer, and smoking, respectively, compared with the normal population. Similarly, the same conclusion was reached in different populations of education level, marital status, and vigorous recreational activities .To the best of our own knowledge, this is the first study with a large sample exploring the relationship between CDAI and the odds of depression. We found a negative association between CDAI and depression after adjusting for all potential covariates, which indicated that CDAI was a protective factor for the development of depression. The trend of increasing CDAI with lower levels of depression appeared significantly. We performed a smoothed curve fitting and found that this negative correlation was non-linear, with 0.16 being the inflection point. Before the inflection point, each unit increase in CDAI was associated with a 30% decrease in the risk of depression. After the inflection point, the risk of depression was found to be reduced by 11% for each unit increase, and the difference between before and after the inflection point was statistically significant.Although existing research on the relationship is still relatively rare, the use of dietary antioxidant properties to intervene in the clinical treatment of depression has long been a hot topic of research today. An analysis study of a small sample of Iranian females aged 14–16 showed a significant inverse relationship between DAI and depression . A studyPrevious studies have shown that DTAC is negatively associated with depression, anxiety, and specific biomarkers of oxidative stress , 21. ThiAccording to the STROBE statement, we conducted subgroup analysis to make better use of data to reveal underlying truths. In the analysis stratified by sex, we found no significant gender differences in the relationship between CDAI and depression. This relationship was not significant among blacks, but it was stronger among Mexican Americans. The risk of depression decreased the most as the CDAI increased in the elderly population when stratified by age. In addition, we observed an independent correlation only in the overweight and obese populations. And the relationship was strongest in the BMI range of 25–27.9. When we performed stratified smooth curve fittings, we found that the relationship was consistent with a non-linear correlation for all groups except for blacks, those with BMI < 18.5, and >28. Moreover, there were no significant interactions between CDAI and other relevant risk factors, which indicated that no other factors had been identified to influence the association between CDAI and depression.There are several limitations to this study: (1) Due to the long time span of this study and the complex way in which the CDAI was constructed, the diet assessment might involve measurement errors and inaccuracies. (2) Bias is inevitable in cross-sectional studies, and we will conduct a large cohort study in the future for further accurate evidence. (3) Since the population observed in this study was Americans, excluding special groups such as minors, we were unable to analyze special populations or other races due to the limited sample size. Therefore, further studies are needed to determine whether those findings apply universally.In conclusion, this cross-sectional study based on six cycles (2007–2018) of data from the NHANE database detected a non-linear negative association between CDAI and depression in the US adult population, after being adjusted for potential confounders. The present study provides a new avenue to explore the factors influencing dietary interventions for depression to reduce its incidence. In the future, additional randomized controlled trials or cohort studies are urgently needed to confirm this finding to provide more accurate and effective prevention and treatment options for depression prevention.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.LZ: project development and research design and manuscript writing. WP and TH: responsibility for data analysis and interpretation and manuscript writing. RC and YS: manuscript editing and interpretation of the results. XW: responsibility for data collection. All authors contributed to the article and approved the submitted version.This work was supported by Shandong Provincial Natural Science Foundation Major Basic Research Project (Grant Number ZR2020ZD17) and Shandong Province Chinese Medicine Science and Technology Project (Grant Number 2021M150).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


We conducted this study to visualize hot spots and trends in the correlation between vitamin D and immunity over the past decade with bibliometric analysis.We collected relevant articles in the Web of Science Core Collection from 2012 to 2021 as the data source, and then used CiteSpace software to perform the data analysis. Some graphics were done with Graphpad software.A total of 1,656 articles were retrieved, with an average citation count of 25.2 times. The United States  has the top number of published articles, followed by China , England , Italy , and India . The most literature is found in areas of Immunology  and Biochemistry Molecular Biology . In terms of institutions, the top five institutions with the highest number of publications all belong to Europe. Among them, the League of European Research Universities (LERU)  has a greater proportion of output articles. The United States Department of Health Human Services  and National Institutes of Health United States  funded most articles. The leading five authors with the largest number of publications were Hewison M , Bergman P , Agerberth B , Carlberg C , and White JH . The top five keywords with the highest co-occurrence frequency are “vitamin d” (367), “d deficiency” (217), “expression” (195), “association” (151), and “d receptor” (132). Among the 17 keyword clusters, the largest cluster is #0 “diet.” Despite cluster #13 “covid-19,” most of the clusters were conducted the studies before 2012.The overall development of research in this field is promising. Western developed countries made outstanding contributions in this area and still take the leading role. But the participation of developing and low-income countries is also impressive. The potential therapeutic effects of vitamin D in immune-related diseases have been noted, especially in multiple sclerosis, COVID-19, etc. This is also the focus and frontier of current research. However, there is still no consensus conclusion in this field. Further research is needed in the future. Vitamin D is a fat-soluble vitamin that belongs to the steroid group. Vitamin D has two forms: vitamin D2  and vitamin D3 . Vitamin D2 is present in plants as a product of ultraviolet B (UVB) radiation from ergosterol—available as a dietary supplement or fortified in foods. Vitamin D3, the product of UVB exposure to 7-dehydrocholesterol, is either synthesized in the human epidermis or taken through dietary sources  . BecauseThe traditional classical role of vitamin D is to regulate calcium homeostasis and bone metabolism. However, based on these surprising discoveries that the VDR and metabolic enzyme are expressed in numerous cell types not involved in bone and mineral metabolism, the views about how vitamin D affects human health changed dramatically. Experimental studies showed that vitamin D exhibited significant biological activity in the innate and adaptive immune systems. Animal studies also suggested that vitamin D administration could result in changes in the onset and progression of diverse immune-related illnesses . These fOf note, the number of research publications in this field has increased rapidly in past years. Bibliometric techniques are used for assessing and characterizing research findings and trends. Bibliometric studies allow for more objective and less biased results when comparing publication contributions from different countries, units, or individuals . In addiWe conducted a systematic search of the literature in the Web of Science Core Collection (WoSCC) database with the following strategy: [TS = (“vitamin d”)] AND TS =  AND Articles OR Review Articles (Document Types), and the search period was set from 2012 to 2021. To avoid the impact of frequent database updates, we completed all the literature searches and data collection on the date of May 11, 2022. A total of 2,445 documents were collected. The final search returned 1,656 papers, including 1,043 articles and 613 reviews. The search process was illustrated in The retrieved literature data were imported into CiteSpace software (version 5.8.R3) to be further analyzed . The detWe evaluated the number of literature, leading countries, leading research institutions, major authors, keywords, and other indicators in the field of vitamin D and immune correlation from 2012 to 2021. Keyword co-occurrence, keyword cluster, and keyword burst graphs were drawn. The keyword co-occurrence graph consists of two parts: nodes and links. The nodes indicate the keywords and the larger the nodes, the more articles in relevant research direction. The links between the nodes refer to the connections between the keywords, and the thicker the links, the closer the associations. Keyword clusters are network groups formed by keywords with similar research topics, reflecting the evolution of themes in the field over a specified time interval. The keyword timeline cluster map brings time into the network and presents the historical trajectory and time span of the keyword evolution in each cluster. Keyword burst shows the sudden increase of keywords in a particular period, indicating a sharp growth in the popularity of a research topic in different periods. Highly cited articles were also analyzed. A comprehensive analysis of these charts could provide a more integrated picture of the development of research trends and hot spots in related fields. Microsoft Excel (version 2016) and Graphpad software (version 9.3.1) were also used for the drawings.The publication quantity is an essential indicator representing the trend of the research field. A total of 1,656 documents matching the limitation were retrieved. There was 30,983 literature cited, and the average citation frequency of each article was 25.2 times. As shown in Of the 116 countries/regions involved in this research field, those with a high number of publications are the United States , China , England , Italy , and India , respectively . In addiAs presented in Two or more keywords simultaneously presented in the same paper are regarded as one co-occurrence. Keyword co-occurrence graph is predicated on the frequency of keyword co-occurrences in the cited literature. Keyword co-occurrence analysis facilitates the identification of research hotspots and trends in the field. As shown in Based on the keyword co-occurrence map, it can be found that the keyword co-occurrence network has gathered into an irregular area, namely a cluster. Briefly, the keyword cluster is a network consisting of keywords with similar study topics to discover the main subjects. In total, 17 separate clusters were obtained. Within each cluster, the topic term used more frequently in articles serves as the cluster marker by CiteSpace. In the calculation rules of CiteSpace, clusters are sorted from zero. That is, cluster #0 is the largest cluster; cluster #1 is the next largest cluster, and so forth. According to the keyword cluster analysis, the five largest clusters are “diet,” “response,” “zinc,” “multiple sclerosis,” and “vitamin d” . In clusIt could be concluded that the association between vitamin D and immune function received long-standing attention during the past decade, especially in immune-related diseases such as multiple sclerosis (MS), tuberculosis (TB), experimental autoimmune encephalomyelitis, and asthma. COVID-19 is also a hot concern.The keyword timeline graph after clustering was plotted using Timeline view in CiteSpace . In the We further mapped the keyword citation burst with CiteSpace . In geneIt can be summarized that the research contents on vitamin D in immunity in the past decade include specific molecular mechanisms, studies with animal models, and clinical trials, especially in the applications in immune-related disorders.Highly cited articles can reflect the hot spots of the research. As seen in As presented in In general, our results show the alignment of highly productive authors, leading institutions and leading countries, and funding agencies. Furthermore, our study indicates the pioneering position of Western developed countries in the field. Developing countries and low-income countries have also made significant contributions to this area.The shift in research hotspots was illustrated in Multiple sclerosis is an inflammatory neurodegenerative demyelinating disease of the central nervous system (CNS), most probably of autoimmune origins. The fourth most highly cited article  reviewedCYP27B1, and CYP24A1, are associated with an elevated risk of MS , “management” (2018–2021), and “prevention” (2019–2021) become popular . In an on levels , 39. Anopatients . This fity in MS . In gene2D. Upon binding to 1,25(OH)2D, VDR is heterodimerized with the retinoid X receptor in the nucleus, which then combines with the vitamin D-response element (VDRE) in the promoter of the target gene, thereby initiating gene transcription   . It was em (RAS) . CurrentMany factors contribute to the varied findings of these studies about vitamin D. It should be noted that these trials differed regarding the region, ethnicity, amount, age, and baseline vitamin D levels of the recruited population. The supplementation regimens also varied. In particular, the RCT design protocol for vitamin D is quite different from those for generic drugs. One essential factor is that any conclusions about the beneficial effects of vitamin D supplementation on health must be validated by baseline and post-treatment vitamin D status in the study population . ResearcCompared with conventional literature reviews, the bibliometric analysis of CiteSpace provides much better insight into the research trends and hotspots, as well as a more comprehensive and objective view of data. Our study presents the first bibliometric analysis of vitamin D concerning immune function, but it still has several limitations. Firstly, we performed the literature search only in the WoSCC database. While it ensures the accuracy of data, such as author names, it may overlook some articles that are only available in other databases. Meanwhile, since the database is continuously updated, the results of this study are somewhat different from the actual number of available literature. In addition, only articles and reviews were selected for our study, but the papers were of mixed quality. Last but not least, only papers in English were collected in this study and we may miss some articles published in other languages. However, we still believe that our visual analysis could give scholars a quick overview of the whole research situation and frontiers in this area.While Vitamin D’s role is widely recognized in bone health, its capability to modulate immune responses has been extensively studied over the past decade. Our study systematically evaluated the role of vitamin D in this area, using a bibliometric analysis of 1,656 publications collected from the WoSCC database from 2012 to 2021. Our findings highlight the significant influence and contribution of developed Western countries, represented by the United States, in this area. It is also noted that many developing countries and low-income countries/regions are engaged in research on this topic. The potential contribution of vitamin D to the treatment and prevention of immune-related disorders, as represented by multiple sclerosis, has received considerable attention. The outbreak of the COVID-19 epidemic also prompted enthusiasm for research in this area. However, despite many hopeful and encouraging findings, there is no established consensus. The integral picture of the role of vitamin D in immunomodulation deserves and needs further study.The original contributions presented in this study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.WH proposed the conception of this study and critically revised the manuscript. XL and YD conducted the data collection and analysis. XL wrote the draft of the manuscript. All authors contributed to the article and approved the submitted version.