Although the current evidence is insufficient to draw a robust conclusion, abnormal placentas should be recognized as a high-risk factor for adverse outcomes during pregnancy.The placenta has several crucial physiological functions that help maintain a normal pregnancy. Although approximately 2–4% of pregnancies are complicated by abnormal placentas, obstetric outcomes remain understudied. This study aimed to determine the outcomes and prevalence of patients with abnormal placentas by conducting a systematic review of 48 studies published between 1974 and 2022. The cumulative prevalence of circumvallate placenta, succenturiate placenta, multilobed placenta, and placenta membranacea were 1.2%, 1.0%, 0.2%, and 0.004%, respectively. Pregnancies with a circumvallate placenta were associated with an increased rate of emergent cesarean delivery, preterm birth (PTB), and placental abruption compared to those without a circumvallate placenta. The succenturiate lobe of the placenta was associated with a higher rate of emergent cesarean delivery, whereas comparative results were observed in terms of PTB, placental abruption, and placenta previa in comparison to those without a succenturiate lobe of the placenta. A comparator study that examined the outcomes of multilobed placentas found that this data is usually unavailable. Patient-level analysis ( Placenta and fetal lineages spatially diverge in the initial days of embryogenesis, and the placenta develops into a single circular or oval-shaped organ during early to middle pregnancy ,2,3,4. TAbnormal placenta can be categorized into circumvallate placenta, succenturiate placenta, multilobed placenta , placenta fenestrate, placenta membranacea, and ring-shaped placenta . The incAlthough pregnancy complicated by an abnormal placenta is not rare, the association between an abnormal placenta and obstetric outcomes remains understudied. Moreover, a systematic review to examine the effects of abnormal placenta on obstetric outcomes has not yet been conducted, which would also investigate the prevalence of abnormal placenta. Furthermore, robust and comprehensive data describing obstetric and delivery outcomes in women with an abnormal placenta remain limited. Therefore, we conducted a systematic review to examine the incidence of abnormal placentas and related obstetric and delivery outcomes.The Institutional Review Board of Osaka International Cancer Institution exempted the need for ethical clearance for the present systematic review, as this study used publicly available and unidentified data. Unpublished patient data were not used in this study.This systematic review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO): registration ID CRD42022336187. The original protocol aimed to examine the effect of abnormal cord insertion and placenta placement on obstetric and delivery outcomes. However, the current study excluded women with abnormal cord insertion due to excessive data found in one study. A systematic search of the literature regarding abnormal placentas was performed according to a modified protocol. The primary objective was to examine the effect of abnormal placentas on obstetric outcomes and also determine the incidence of abnormal placentas during pregnancy. The secondary objective was to explore the delivery outcomes of women with abnormal placentas.A systematic literature search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines  was perfi) case report (1 or 2), (ii) case series (3–10), and (iii) original articles (11≥).Previous studies on abnormal placenta were screened by scrutinizing the titles, abstracts, and full texts of candidate published works, as previously described, with some modifications ,16. All i) a comparative study ; (ii) studies wherein the incidence of abnormal placenta was clarified; (iii) studies where obstetric outcomes in women with abnormal placenta were examined; (iv) a case report or case series that reported a woman or women with abnormal placenta.Studies fulfilling the following inclusion criteria were incorporated in the current study: (i) studies wherein the number of women with abnormal placentas was unclear; (ii) studies with missing or unavailable information regarding the outcomes of interest  in women with abnormal placenta; (iii) studies wherein specific outcomes of each type of abnormal placenta patients were unavailable, (iv) articles not written in English; (v) conference abstracts, narrative reviews, systematic reviews, and meta-analyses.The following studies were excluded:  and double-checked by Shinya Matsuzaki and Misooja Lee. The following information was documented: publication year, study location, leading author’s name, number of pregnant women, and outcomes of interest. The outcomes of interest in this study were obstetric outcomes ; incidence; and delivery outcomes (rate of cesarean delivery and emergent cesarean delivery). Since studies on placenta membranacea were scarce, patient-level analysis (combining information from case reports or case series) was performed.The risk of bias in eligible studies was assessed using the risk of bias in non-randomized studies of interventions tool (ROBINS-I) in accordance with the previous studies ,19,20,21The association between abnormal placentas and assisted reproductive technology (ART) was examined during sensitivity analysis, the method of which has been described elsewhere . Since tThe odds ratios (ORs) of the risk of outcomes  from the identified studies were calculated using the 95% confidence intervals (95% Cis) of the reported values. To calculate the incidence of abnormal placentas, the number of pregnant women with abnormal placenta was divided by the total number of pregnant women included in the analysis.I2 statistic, which measures the percentage of total variation across the studies. According to the Cochrane Handbook for Systematic Reviews of Interventions (version 6.3), heterogeneity was assessed based on the value of I2, with some modifications from a previous study [Study heterogeneity was assessed using the us study .Meta-analysis was performed using RevMan, version 5.4.1 . All images were created using RevMan 5.4.1. Images were edited using Adobe Illustrator CS5 . Data from all outcomes were entered into RevMan 5.4.1, such that negative effect sizes or relative risks of <1 favored active intervention.p-value < 0.05 was considered statistically significant.Fisher’s exact test or the Chi-square test were used to examine differences in baseline demographics between the two groups. All statistical analyses were based on two-tailed hypotheses, and a The study selection scheme is illustrated in n = 48), 26 were case reports [n = 15, 31.3%) [n = 11, 22.9%) [n = 8, 16.7%) [The metadata of the 48 eligible studies are shown in  reports ,63,64,65 reports ,59,60,61 reports ,54,55,62, 31.3%) ,57,58,63, 22.9%) ,49,51,60, 16.7%) ,59,61,62, 16.7%) ,47,64,65Data regarding circumvallate placenta were available in 18 studies ,55,57,62Six studies were comparator studies in the context of circumvallate placenta ,44,45,62n = 8) demonstrated a possible severe bias  in all studies (Risk of bias assessment for comparative studies ( studies .n = 18), 15 studies were original research articles and 3 were case reports (n = 15), 6 examined obstetric outcomes [Data regarding circumvallate placenta were reported in 18 studies ,55,57,62 reports . These soutcomes ,44,45,62outcomes  Table 1n = 18, 1outcomes ,28,30,31To examine the obstetric outcomes in women with a circumvallate placenta, the ORs of PTB, FGR, and placental abruption were calculated. Four studies examined the risk of PTB in women with a circumvallate placenta ,12,26,62p < 0.01, I2 = 89%) compared to those without circumvallate placenta (n = 4), women with a circumvallate placenta had a significantly higher incidence of FGR than women without a circumvallate placenta . Considering the lack of heterogeneity, we conducted a fixed effects analysis in the unadjusted pooled analysis to determine the risk of placental abruption in women with circumvallate placentas. In this analysis, women with circumvallate placenta were associated with a significantly higher risk of placental abruption  compared to those without a circumvallate placenta. In the pooled analysis of four studies with random effects analysis due to considerable heterogeneity, the rate of PTB in women with circumvallate placenta was significantly higher  demonstrated that women with a circumvallate placenta had a similar rate of cesarean delivery  as those without a circumvallate placenta  was similar to those without a circumvallate placenta in the unadjusted pooled analysis. In contrast, women with circumvallate placenta were more likely to have an emergent cesarean delivery  compared to those without a circumvallate placenta.Two studies stratified the type of cesarean delivery into elective and emergent cesarean deliveries ,12. In tTwo studies mentioned postpartum hemorrhage (PPH) in women with a circumvallate placenta. Suzuki et al.  reportedThe association between ART pregnancy and a circumvallate placenta was determined in six studies ,28,30,31n = 20), 8 studies were original research articles [The outcomes of succenturiate lobe placenta were mentioned in 20 studies  9,13,24,60,61,63articles ,31,44,46articles ,49,51,63n = 8), three examined the obstetric outcomes and rate of emergent cesarean delivery, PTB, placental abruption, and placenta previa in women with succenturiate lobe placenta. Two studies had overlapping data [A total of eight original research articles that examined obstetric outcomes or the relationship between ART pregnancy and the succenturiate lobe placenta have been published . Of thesing data ,46. Thering data . p = 0.24, I2 = 26%) compared to those without succenturiate lobe placenta. On the other hand, comparative results were observed for PTB , placental abruption , and placenta previa .The ORs of emergent cesarean delivery, PTB, placental abruption, and placenta previa in women with succenturiate lobe placenta were determined in comparison to those without succenturiate lobe placenta . In the p < 0.01, I2 = 93%; >1000 mL: OR 2.26, 95% CI 0.37–13.75; heterogeneity: p < 0.01, I2 = 93%.Two original research articles examined the risk of PPH in women with succenturiate lobe placentas. In a Japanese study reported by Suzuki et al. , the OR The prevalence of succenturiate lobes of the placenta was reported in eight studies ,31,44,46Ten studies included women with multilobed placentas ,39,48,50n = 10), three were original research articles. On the other hand, none of the studies examined the obstetric outcomes of women with a multilobed placenta. The remaining seven studies reported 12 women with multilobed placentas. However, obstetric outcomes were difficult to examine due to the limited data and heterogeneity of the included cases.Of the 10 studies , five were case reports [Seven studies reported women with placenta membranacea  34,42,5,59,64,65 reports ,58,64,65n = 15), the rate of abortion was 40% (6/15) and the rate of preterm birth excluding women with intrauterine fetal death was 26.7% (4/15). Three women had intrauterine fetal death (20.0%), and 2 of 15 women (13.3%) had full-term deliveries. Although the definition of PAS has not been clarified, 6 of the 15 women (40%) had PAS.Patient-level analysis was performed to examine obstetric outcomes in women with placenta membranacea . A totalThe prevalence of placenta membranacea was mentioned only in one Chinese study. In the present study, the prevalence of placenta membranacea was 0.004% (n = 9), five (55.6%) had cesarean delivery and two (22.2%) experienced PPH. None of the women who had abortions experienced PPH.After excluding abortion cases, nine eligible women were included in the analysis to examine the rate of cesarean deliveries. Of them (i) circumvallate placenta was associated with a high risk of emergent CD, PTB, FGR, and placental abruption; (ii) succenturiate placenta may be a high-risk factor for emergent CD and PPH, whereas it may not be a risk factor for PTB, FGR, or placental abruption; (iii) obstetric and delivery outcomes in women with multilobed placentas were limited; (iv) the prevalence rates of circumvallate placenta, succenturiate placenta, multilobed placenta, and placenta membranacea were 1.2%, 1.0%, 0.2%, and 0.004%, respectively.The principal findings of this study were as follows:  may exist. Further, the wide range of study duration in the current study (1974–2022) may have resulted in a bias in the analysis of PTB and FGR. In particular, different definitions of abnormal placenta among studies may have caused severe bias. Thus, this point should be recognized as a substantial limitation of this study. Second, the quality of the diagnosis of an abnormal placenta was unknown in the original research articles included in the analysis. Most authors did not clarify the definitions and diagnostic criteria for abnormal placentas. These are critical limitations, and readers need to be aware of these issues when interpreting the results of the current study. Third, women with abnormal placenta are more likely to have co-existence of other placental or cord abnormalities, such as PAS, velamentous cord insertion, and vasa previa ,17,66,67Fourth, we modified the protocol of the systematic review due to excessive data in one study, which had the potential to cause bias. During the literature search, we excluded studies whose abstracts were unavailable in the search engines. Consequently, old studies and letters were excluded, and this is noteworthy. Fifth, the current study may have had a publication bias that should be recognized. For instance, women without a poor prognosis due to an abnormal placenta and undiagnosed cases may not have been reported. Lastly, since the number of included studies was limited, this study adds limited new findings to the current evidence. Nevertheless, current systematic review increases the robustness of findings regarding the outcomes of abnormal placenta. We believe that this systematic review provides the current evidence of the effect of an abnormal placenta on obstetric and delivery outcomes for clinicians. p < 0.01) and preterm premature rupture of membranes  were significantly higher in women with a circumvallate placenta (n = 92) compared to those without a circumvallate placenta (n = 9057). These features may lead to increased rates of PTB and placental abruption. Circumvallate placenta was associated with increased rates of FGR, PTB, and placental abruption in the present study. These findings were consistent with those of the previous studies ,44,45,62Since a circumvallate placenta is associated with a poor prognosis during pregnancy, a definite method for detecting this type of abnormal placenta is warranted. Suzuki et al. reported that women with placental thickness greater than 3.0 cm had circumvallate placenta in approximately 20% of deliveries and proposed that measurement of placental thickness would be useful for screening for circumvallate placenta .Unlike circumvallate placenta, studies that examined the obstetric outcomes of succenturiate lobes of the placenta, multilobed placenta, and placenta membranacea are scarce because of their rarity. Although obstetric outcomes regarding these types of abnormal placenta remain understudied, particular attention should be paid to the presence of type II vasa previa in women with succenturiate lobes of the placenta and multilobed placenta . In our The present systematic review reported the prevalence of abnormal placenta, while no studies have examined the trends of abnormal placenta. Moreover, data regarding patient characteristics in women with abnormal placenta are scarce, and therefore, it is difficult to estimate the trends associated with abnormal placenta. To determine the trends of abnormal placenta, a future nationwide study is required.Our study found that women with a circumvallate placenta and succenturiate lobes of the placenta were more likely to undergo emergent cesarean delivery compared to those without an abnormal placenta. The unique feature of the present study is the stratification of cesarean delivery into elective and emergent cesarean delivery, which showed that emergent cesarean delivery was performed more commonly in women with circumvallate placenta and succenturiate lobes of the placenta, whereas elective cesarean delivery was not. According to our hypothesis, the reason for the increased rate of emergent cesarean delivery may be the increased rate of FGR due to placental insufficiency in women with circumvallate placentas . Since FThe association between abnormal placenta and fetal anomalies, cognitive and cardiovascular development is a riveting topic. For instance, single umbilical artery has been associated with increased rate of fetal anomaly ,73. HoweThe rate of occurrence of circumvallate placenta was found to be similar between ART and non-ART pregnancies in the present study, whereas ART pregnancy was associated with an increased rate of a succenturiate lobe of the placenta in previous studies ,79. The A circumvallate placenta is an abnormality in the shape of the placenta. Succenturiate lobes of the placenta and multilobed placenta may result from localized atrophic changes due to poor decidualization ,81,82. TAn abnormal placenta may be associated with adverse obstetric outcomes such as an increased rate of emergent cesarean delivery, PTB, FGR, and placental abruption. However, it is important to recognize that the prognosis depends on the type of abnormal placenta. Therefore, the results of the present systematic review will help clinicians be more aware of these adverse outcomes that may occur in women with abnormal placentas. In particular, the OR of placental abruption in women with a circumvallate placenta was high (approximately 10), and clinicians need to comprehend this risk to improve maternal and neonatal outcomes.Although abnormal placenta are associated with adverse obstetric outcomes, the characteristics of patients with abnormal placenta are understudied. Further studies are required to assess and analyze the characteristics of women with abnormal placenta. Being aware of the risk factors in patients with characteristics of abnormal placenta may help in the diagnosis of an abnormal placenta during pregnancy. A nationwide study focusing mainly on the risk of an abnormal placenta may address this problem. Statistical analyses, such as multivariate analysis, propensity score matching, and inverse probability of treatment weighing, that were not performed in the studies included in this the present systematic review, would be helpful in excluding confounding factors. No study has examined the mechanism of abnormal placenta. Therefore, future studies focusing on the development of abnormal placenta may shed light on some interesting findings. These examinations may be helpful in identifying the risk of abnormal placenta. To promote basic research, future studies on the relationship between ART and abnormal placenta are warranted.


Conclusions: At 2 years, marginal bone loss following prosthetic rehabilitation was shown to be influenced by multiple factors. Correct implantological planning is of vital importance for successful rehabilitation.Introduction: The aim of this prospective descriptive study was to analyse the possible variables associated with marginal bone loss in rehabilitated implants  two years after their prosthetic loading. Materials and Methods: Three clinical centres collaborated for a period of two years after the prosthetic rehabilitation of the implants , in which marginal bone loss and the possible associated variables were evaluated. The collection form comprised different variables throughout different stages of the implant procedure, from implant insertion to the subsequent prosthetic rehabilitation, over a two-year period. Data of the patients and implant characteristics were studied. Statistical analysis was performed with SPSS for qualitative  and quantitative variables (Kolmogorov–Smirnov test). Results: The total study sample consisted of 218 implants . The sample presented a frequency of 99 men (45.4%) and 119 women (54.6%). The mean age of the patients among the reported cases was 58.56 ± 10.12 years. A statistically significant association was found between marginal bone loss 2 years after prosthetic rehabilitation placement and several variables, including age (under 55 years, 0.25 mm ± 0.56; 55–64 years, 0.74 mm ± 0.57; over 65 years, 0.63 mm ± 0.55;  Radiographic observation of marginal bone loss, defined as bone lost around the crestal area of the implant , is a crMarginal bone loss around dental implants continues to be studied in detail by multiple authors, and it has been observed that it can be influenced by a multitude of factors, such as systemic factors of the patient, local factors, factors related to the implant design, the type of prosthesis, and the materials used ,5.The analysis of marginal bone loss has been proposed to be studied one year after the placement of the prosthetic rehabilitation and masticatory load, since during this initial period, dimensional changes ranging between 1.5 and 2 mm are established . Some auAlthough radiology has seen important advances in recent years, periapical radiology is still preferred for the studying MBL, even though it would be limited to the mesial and distal aspects of the implant . ArticleBeyond this point, studies that focus on the MBL are still fully valid to assess the different factors that influence the maintenance of peri-implant bone ,11.The aim of this study was to conduct a prospective multicentre study analysing marginal bone loss around placed dental implants, along with the factors associated with increased marginal bone loss 24 months after prosthetic loading.Specifically, the following factors will be studied: gender, age, location of the implant, type of implant, diameter and length of the implant, type of bone, type of prosthetic connection, type of prosthetic rehabilitation, and insertion torque.A prospective multicentre study was conducted to analyse the variables associated with marginal bone loss 2 years after the prosthetic rehabilitation of implants . We had the collaboration of three clinical centres that allowed us to access the database of the implants placed and their subsequent reviews over the course of two years. The patients included in the multicentre study were healthy patients who were not taking any medication at the time of the implant placement.The exclusion criteria applied were as follows: patients with serious systemic diseases, such as recent heart attack, coagulation disorders, cancer, uncontrolled diabetes, psychiatric contraindications, and active infection; as well as pregnant or lactating women. Patients with pharmacological treatments capable of affecting bone healing (bisphosphonates) and gingival health, such as some anticonvulsants (phenytoin), immunosuppressants (cyclosporin A), and calcium channel blockers , were also excluded.In each of the collaborating centres, the implants were placed by a surgeon with more than 10 years of experience in implantology practice. The same surgical protocol for implant placement was used: infiltrative anaesthesia with articaine 1%, elevation of a mucoperiosteal flap, surgical drilling following the protocol of the commercial company according to the type of bone, implant placement and ISQ measurement , placement of the closure cap, and suture of the flap with supramyd 5/0 . Analgesic (metamizole magnesium 575 mg) and antibiotic (amoxilicin 1 gr) medications were administered to all patients every eight hours for 3 days. Immediate prosthesis placement was performed in all cases within the first 24 h after implant placement, and the follow-up period began at that time, regardless of when the definitive prosthesis was made  .The variables evaluated included implant position in the maxillary or mandibular bone; type of implant placed; implant diameter; implant length; type of bone  according to Misch’s classification; type of attachment used ; type of restoration ; if the torque used was greater than 35 N/cm; if crestal expansion procedures were performed; if there was implant failure at 2 months, 6 months, and 24 months; and the cause of the failure was analysed.Implant position was classified into four categories: maxillary anterior, including the upper central incisor (ICS), upper lateral incisor (ILS), and upper cuspid (CS); maxillary posterior, including the upper molars (MS) and upper premolars (PMS); mandibular anterior, including lower central incisor (ICI), lower lateral incisor (ILI), and lower cuspid (CI); and mandibular posterior, including lower molars (MI) and lower premolars (PMI).The implant design was classified into four categories: internal conical, including the M12 type implant; external conical, including the N6 type implant; internal cylindrical, including L35- and M8-type implants; and external cylindrical, including L6-type implant .Marginal bone loss was measured radiographically mesially, and distally vertically from the implant crestal point of reference to the first bone-to-implant contact axially parallel to the implant at 2 months after prosthetic loading.Marginal bone loss was evaluated at three centres by the means of periapical radiography using the parallelisation technique, which allowed for an appropriate measurement of mesial and distal marginal bone loss using Carestream Dental software . Only one person conducted the measurements at each centre, and this person received prior qualification training in relation to the program used and the measurement methodology.The MBL measurement was performed using the implants present in the radiograph to calibrate it, thus obtaining a real measurement of the mesial and distal bone loss of the implants. This methodology has already been applied in many studies, such as ones by Sargolzaieet al.  and StacThis study was conducted following the ethical principles for medical research on humans as defined by the Declaration of Helsinki and following the standards of good clinical practice. Approval was obtained from the Ethical Committee of Virgen del Rocío and Virgen Macarena Hospital (DTL-OXT-17).The sample size required to test the hypothesis on the difference in bone loss of the implants between the two groups was calculated. In the literature , we founFollowing the standard procedure, to detect possible differences between treatments, we accepted a risk of 5% and a statistical power of 95, which produced a value of 30 implants in each comparison group.The statistical significance of the results obtained was calculated using IBM SPSS Statistics 24.0 . For qualitative variables, univariate logistic regressions, Chi-squared tests, and cross-checks between the variables were performed to determine the statistical significance of the differences. To determine the groups that made the difference, we used Haberman’s corrected standardised residuals, which allowed us to obtain the significance of the cells independently.For quantitative variables, cross-checks were performed, and the normality test showed that not all variables analysed followed a normal distribution (Kolmogorov–Smirnov test). Therefore, the results of the corresponding non-parametric tests were considered for statistical significance, including Mann–Whitney U test for crossover with dichotomous variables or Kruskal–Wallis to determine the overall significance between the variables with more than two categories. In addition, when the test was significant, the Mann–Whitney U test was used for comparisons between the groups (two by two) to determine which groups were different from each other.p < 0.05 , whereby the lower the figure, the greater the significance.An association was considered statistically significant for values of The total study sample consisted of a total of 218 implants, of which 97 (44.5%), 91 (41.7%), and 30 implants (13.8%) were placed at centres A, B, and C, respectively. The mean age of the patients analysed was 58.56 ± 10.12 years, among which patients younger than 55 years made up 31.2% of the sample, those between 55 and 64 years comprised 43.1% of the sample, and 25.7% were over 65 years of age. A higher frequency of women was observed (54.6%) than men (45.4%).p < 0.0001). In relation to gender, a greater difference in marginal bone loss was observed in women (p < 0.0001). Greater marginal bone loss was observed in patients between 55 and 64 years of age (p < 0.0001), and according to the implant model, a greater difference was observed in external cylindrical implants (p < 0.0001). The diameter of the implant was greater in implants with a diameter greater than 4 mm (p < 0.0001), and according to the type of bone, a greater difference was observed in type D1 (p < 0.01). The type of attachment revealed a greater difference in bone loss in implants with straight transepithelial implants (p < 0.0001). Finally, when analysing the type of rehabilitation, a greater difference in marginal bone loss was observed in complete rehabilitations (p < 0.05) and implants in which the insertion torque was less than 35 N/cm (p < 0.01).Marginal bone loss is encompassed within a series of criteria used to define peri-implantitis or peri-implant disease, in which unfavourable changes occur at the level of the soft and bony tissues surrounding the dental implant once it is placed and subjected to the masticatory load ,13.A multitude of radiographic means were employed for the assessment of marginal bone loss  ,15,16,17p < 0.001) [p < 0.0001), and more so in women than in men (p < 0.0001), 2–24 months after prosthetic loading, which is in agreement with the previous study.A statistically significant increase in marginal bone loss was observed with increasing age . Other a< 0.001) . In thisMultiple authors have found no statistically significant marginal bone loss differences due to the position in the arch in which the implant was placed, including the maxilla, mandible, anterior zone, and posterior zone ,21,22. Ip < 0.05) [p < 0.0001) between 2 and 24 months after prosthetic loading.In relation to implant shape, a previous study found a statistically significant difference between marginal bone loss and the shape of cylindrical (0.88 ± 0.43 mm) and conical (0.61 ± 0.34 mm) implants, with a higher marginal bone loss observed in cylindrical implants ( < 0.05) . These rp < 0.0001). These data are consistent with other studies published in the literature [In relation to implant connection, previous studies have commented that there are no statistically significant differences associating marginal bone loss with either an internal or external implant connection ,25. In tterature ,27.In relation to the implant diameter, previous studies have found an association between larger-diameter implants and greater marginal bone loss ,28. In tNumerous authors have analysed whether the length of the implant influences marginal bone loss, finding no statistically significant differences ,35,36,37A review of the literature shows that numerous authors have not drawn a significant association between bone type or quality and marginal bone loss ,29,30,38p < 0.0001). Some authors have found greater marginal bone loss when the definitive abutment was not placed after surgery [In relation to the type of attachment, some authors have observed no significant differences in marginal bone loss between the use of a curved or straight abutment after one year of follow-up . In this surgery ,40,41. IIn relation to surgical technique, previous studies have found no statistically significant differences in marginal bone loss between performing a mucoperiosteal flap prior to the dental implant placement ,43. In tThe type of prosthetic rehabilitation has been considered an influential factor in marginal bone loss . In thisPrimary stability after implant placement undergoes variations during the healing process . In thisSeveral authors have found no statistically significant differences in marginal bone loss in relation to the insertion torque ,46. In tAmong the limitations that we have highlighted in our study, there was an inherent weakness of multicentre studies since they require additional control from all research centres. Likewise, the application of a two-dimensional radiological evaluation method limits our study, although it is a widely validated methodology used by current authors ,9,10.The measurement of the initial keratinised gingiva that the patients presented, as well as the milling applied, is an aspect that could also have been controlled and would have yielded interesting data, as has been pointed out in some studies ,47.Finally, and before moving on to the conclusion, where we will summarise the key results in relation to the objectives of our study, we should point out that the possible biases of our study, discussed above, can operate in either direction, given the multitude of controlled variables  and the difficulties of conducting a multicentre study.On the contrary, conducting a multicentre study with several surgeons and rehabilitators provides the results of our study with a strong external validity, and its results could easily be extrapolated to routine practice.According to the results obtained in this study, we can indicate that marginal bone loss is sensitive to multiple factors, such as the prosthetic connection, age, gender, implant width, bone density, type of rehabilitation, and torque insertion. However, the length of the implant did not seem relevant to the peri-implant bone loss studied within a two-year follow-up of our sample. However, we must be cautious in assuming these results, given the limitations of the study, the multiplicity of analyses, and other issues discussed above.


Based on the directed relation graph with error propagation (DRGEP) reduction method, a detailed mechanism consisting of 119 species and 527 reactions for n-decane was simplified. As a result, a skeletal mechanism comprising 32 species and 73 reactions was derived. Subsequently, the quasi-steady state approximation (QSSA) reduction method was employed to further simplify the skeletal mechanism, resulting in a reduced mechanism with 18 species and 14 global reactions. A comparison between the reduced mechanism, skeletal mechanism, and detailed mechanism revealed that the reduced and skeletal mechanisms successfully replicated the combustion characteristics of the detailed mechanism under a range of initial conditions. These models can be credibly incorporated into large-scale combustion simulation, serving as a solid foundation for enhancing computational efficiency. In recent years, the numerical simulation of aviation fuel has gained significant importance in optimizing engine designs for performance, efficiency. Aviation fuel is composed of hundreds to thousands of hydrocarbon compounds, including paraffins, cycloparaffins, aromatics, and alkenes, with a wide range of molecular weights. Unfortunately, detailed chemical kinetic mechanisms that accurately describe the combustion of many components in aviation fuels are currently unavailable. Therefore, to simulate the combustion of aviation fuels, simplified model fuels (surrogates) consisting of a few representative hydrocarbons must be utilized. Detailed kinetic mechanisms offer comprehensive and accurate representations, however they tend to be large and time-consuming when employed in practical three-dimensional computational fluid dynamics (CFD) simulations. As a result, mechanism reduction becomes essential to efficiently apply such extensive mechanisms in CFD simulations of complex flow fields.Mechanism reduction has been extensively studied, and numerous methodologies have been developed over the past few decades ,12,13,1410H22) has been selected as a single-component surrogate fuel to develop a detailed chemical kinetics mechanism for RP-3 aviation kerosene. Over the past few decades, numerous studies have focused on modeling the combustion properties of n-decane. The n-decane mechanisms presented in previous studies are summarized in China RP-3 kerosene is a crucial hydrocarbon fuel widely used in aeroengine because its high energy density and stable thermodynamic properties. Moreover, given that the physical and chemical properties of n-decane closely resemble those of RP-3 kerosene, n-decane  species are identified using CSP analysis.An analytical solution is generated for the concentrations of the QSS species. Finally, the resulting reduced mechanism is rigorously validated against the detailed mechanism across a wide range of pressure, temperature, and equivalence ratios to ensure its accuracy.In a combustion chemical mechanism, the thermodynamic information is mainly represented by the thermochemical quantities associated with each species, and the kinetic information is associated with the set of reactions that describe how these species react with each other. The thermodynamic parameters of a combustion reaction mechanism include the enthalpy of species, heat capacity, and entropy. The temperature dependent heat capacity, standard enthalpy and entropy are usually represented as two seven term form “NASA polynomials” :(1)CP0R=A is the pre-exponential factor, n is the temperature coefficient, aE is the activation energy, and R is the gas constant in J·K−1. It is important to note that each species has its own transport properties which are employed for the evaluation of gas-phase multicomponent viscosities, thermal conductivities, diffusion coefficients, and thermal diffusion coefficients.The rate coefficients of the combustion reaction mechanism are expressed using a modified three-parameter form of the Arrhenius equation:The directed relation graph with error propagation (DRGEP) method, which has evolved from the original DRG method, was proposed by Pepiot-Desjardins and Pitsch . The DRGAB values, is lost by the binary truncation. To address these limitations, the DRGEP method is proposed to modify the DRG method by considering the propagation of error due to species removal down reaction pathways. In DRGEP, the interaction coefficient is computed as follows:Aνi, represents the net stoichiometric coefficient of species A in the ith reaction and iω denotes the net reaction rate for the ith reaction. I denote the total number of reactions in the detailed mechanism. If the ith elementary reaction involves species A, the value of Biδ is 1; otherwise, it is 0. AP and AC represent the production and consumption rates of species A, respectively.However, the DRG method supposes the directed couplings of all species that are selected to be retained in the skeletal mechanism, which may not provide a comprehensive representation. Furthermore, contribution information about contribution strengths, as captured by the rABr, p, represents the error propagation through a certain pathway and is defined as the product of intermediate interaction coefficients between target species A and species B through a certain path, p, in the directed graph. An overall interaction coefficient (OIC), ABR, is then defined as the maximum of all PICs between the target and each species of interest:After calculating the interaction coefficients for all species pairs, a path-dependent interaction coefficient (PIC), ABR is below a user-specified threshold, εEP, and reactions consisting of unimportant components are also eliminated from the detailed mechanism. The optimal threshold is chosen by an iterative manner in this DRGEP implementation.Species B is considered to be unimportant and will be removed if AIi, is the importance index of the ith reaction to the production rate of the Ath species. If the importance index, AIi,, is below a user-defined threshold, ε, the ith reaction is considered to be unimportant for the reaction state.Lu and Law  have devJ, is defined as the derivative of the reaction rate vector, f, with respect to the species concentration vector, c. The chemical reaction kinetic model consists of K species and I elementary reactions. In this context, c represents the time rates of species concentration, while f represents the species concentrations themselves. The diagonalization matrix, Λ, is constructed by arranging the eigenvalues of the Jacobian matrix. Additionally, the matrices X and Y consist of the row and column eigenvectors of the Jacobian matrix, respectively. The criterion can be expressed as follows [In our study, the skeletal mechanism was next reduced using the QSSA method. However, two crucial challenges needed to be addressed when applying the QSSA method: the identification of QSS species and the efficient and reliable solution of the resulting algebraic equations . QSS spe follows :(13)DsloD represents the projection matrix onto the slow subspace and ε denotes a small threshold for the relative error tolerance. If the ith species satisfies Equation (13), it is considered to be a QSS species.ik represents the rate of reaction i, τ(2ik) denotes the ignition delay when the rate of reaction i is doubled, and τ(ik) represents the nominal value of the ignition delay. Therefore, a positive sensitivity value indicates that the ignition delay increases when the rate of reaction i is doubled.Brute force sensitivity analysis is performed through constant-volume adiabatic simulations. The percent sensitivity is defined according to the following equation :(14)%SenIn our study, we selected Honnet’s n-decane mechanism  as origiThe newly obtained detailed mechanism, which originally consisted of 75 species and 373 reactions, underwent reduction to generate the skeletal mechanism using the DRGEP method. This was followed by further elimination of unimportant reactions. During the skeletal reduction process, the ignition delay time was chosen as the target parameter and validation simulations were performed over a wide range of initial conditions. These conditions included varying pressures from 1 to 10 atm, equivalence ratios ranging from 0.5 to 2.0, and initial temperatures spanning from 1000 K to 1600 K. The fuel, oxygen, and nitrogen were selected as the initial components for the mechanism reduction.By adjusting the threshold value, ε, a series of skeletal mechanisms of different sizes were generated. After careful analysis, a threshold value of 0.20 was selected as the criterion, as it resulted in a reduced skeletal mechanism with 32 species. By eliminating unimportant elementary reactions from the aforesaid 32-species mechanism, a final skeletal mechanism consisting of 32 species and 73 reactions was obtained. The error in predicting the ignition delay remained within an acceptable range (30%) for this reduced skeletal mechanism.2 = OH + O, which exhibits the largest inhibiting effect among all the reactions. Conversely, the reaction NXC10H22 + H = SXC10H21 + H exhibits the largest positive sensitivity value in the results derived from the skeletal mechanisms. Additionally, reactions involving HO2, H, OH, and CH3 radicals also play significant roles in the combustion properties of n-decane at high temperatures.Sensitivity analysis provides insights into the impact of reactions on the concentration of a specific species. To illustrate the key reactions in the skeletal mechanism influencing the ignition delay time during high-temperature combustion of n-decane, sensitivity analysis was performed for the ignition delay time in an n-decane/air mixture at different equivalence ratios, as shown in 2, NXC3H7, PXCH2, PXC7H15, PXC5H11, SXC10H21, HCCO, HCO, TXCH2, O, C2H3, CH3O, H, and OH. Through the QSSA reduction, a final reduced mechanism with 18 species and 14 lumped global steps was obtained. When compared to the detailed mechanism, the maximum relative error in predicting ignition delay for the reduced mechanism is 18% and the average ignition error is 16.54%.The 32-species skeletal mechanism obtained earlier underwent further reduction using the QSSA method. The first step in QSSA-based reduction is to identify the QSS species. To achieve this, a criterion based on CSP was applied to the obtained reduced mechanism. This criterion was carried out at temperatures of 1000 K, 1200 K, 1400 K, and 1600 K, pressures of 1.0 atm and 10 atm, and equivalence ratios of 1.0 and 2.0. Based on this criterion, 14 species were identified as QSS species. These species are SXROTo further verify the performance of both the skeletal mechanism and the 18-species reduced mechanism, comprehensive comparisons were conducted between the simulation results obtained using the detailed mechanism and those obtained using the reduced mechanism. The direct comparisons encompassed various aspects and conditions, providing a thorough evaluation of the accuracy and predictive capability of the reduced mechanism in capturing the combustion behavior.internal combustion engines, as it heavily influences the combustion and emission characteristics. Therefore, in this section, the newly developed skeletal mechanism and reduced mechanism are validated against available experimental ignition delay data or corresponding simulation results obtained from the detailed mechanism. Modeling simulations were conducted with SENKIN using the CHEMKIN II program [The ignition delay of a fuel/air mixture holds significant importance in  program .Furthermore, as shown in To further illustrate the accuracy of species concentrations in auto-ignition, a comparison of the species profiles in auto-ignition simulations is presented in In Extinction is another important combustion property to validate chemical kinetic mechanisms and is also very important for kerosene combustion in jet engines. In The present study developed a reduced n-decane mechanism consisting of 18 species and 14 lumped global reactions using the DRGER and QSSA methods, which strike a good balance between the size and accuracy of the mechanism. Then, the resulting reduced mechanism was rigorously validated against the detailed mechanism across a wide range of operation conditions to ensure its accuracy. These modeling simulation findings indicate that the reduced mechanisms, particularly the 18-species reduced mechanism, effectively capture the essential combustion behavior, such as the temperature profiles observed in the detailed mechanism. Aforementioned results show that as the size of the mechanism decreases, its performance in combustion simulations gradually becomes worse.


Collapsed across the anchor scheme, there were decreases in torque  and NME . There were no significant (p > 0.577) changes for EMG AMP. For the PTQ, there were no differences (p > 0.05) between anchor schemes. There were, however, inter-individual differences in the response scores. The current findings indicated that performance fatigability was likely due to peripheral fatigue (based on NME), not central fatigue (based on EMG AMP). Furthermore, the use of a PTQ may serve as a simple tool to assess the contributions of perceived sensations to task termination.The present study examined the effect of anchor schemes on the time to task failure (TTF), performance fatigability, neuromuscular responses, and the perceived sensations that contributed to task termination following the sustained, isometric forearm flexion tasks. Eight women completed sustained, isometric forearm flexion tasks anchored to RPE = 8 (RPEFT) and the torque (TRQFT) that corresponded to RPE = 8. The subjects performed pre-test and post-test maximal isometric contractions to quantify performance fatigability and changes in electromyographic amplitude (EMG AMP) and neuromuscular efficiency (NME). In addition, the subjects completed a post-test questionnaire (PTQ) to quantify the contributions of perceived sensations to task termination. Repeated measure ANOVAs were used to assess the mean differences for TTF, performance fatigability, and neuromuscular responses. Wilcoxon Signed Rank Tests were used to assess the differences between anchor schemes for the average values from the PTQ item scores. For TTF, the RPEFT was longer than the TRQFT (174.9 ± 85.6 vs. 65.6 ± 68.0 s;  Perceived fatigability refers to an increase in the subjective perception of fatigue that emerges during a sustained task and is affected by factors related to the psychophysiological state of the individual, including perceptions of effort, pain, or discomfort, as well as motivation, affective valence , mood, expectations, and/or executive function  [The study of fatigue has become increasingly specialized with a variety of definitions and divisions in research outcomes. The multiple definitions of fatigue have complicated the ability to characterize performance-related and/or psychophysiological responses during a fatiguing task. Therefore, Kluger et al.  and Enokhaviors) ,2,3.It has been suggested  that theGiven the unique nature of the RPE-Clamp model, recent studies have examined the interactions among factors associated with performance fatigability and perceived fatigability, during ,8,9 and Exercise-induced adjustments to the neuromuscular system are often assessed by examining the time domain of the EMG signal. It has been suggested ,15 that While a number of studies ,24,25,26An a priori G*Power3 analysis determined that a minimum of 6 subjects were required to demonstrate mean differences between 2 dependent groups using repeated-measures ANOVAs, based on an effect size of  = 0.551 , a power = 0.551  women , and all subjects completed a Health History Questionnaire and signed a written informed consent prior to testing.125) to reflect the point in the range of motion that approximated maximal isometric torque production [The subjects visited the laboratory on three separate occasions  separated by 24 to 96 h. The initial visit was an orientation session where demographic information was recorded, and the subjects were familiarized with the standardized warm-up, the testing protocol, and the Omnibus-Resistance Exercise 0–10 (OMNI-RES) ,19,20 anoduction .125. The subjects were then familiarized to the OMNI-RES scale [125 as well as 2 repetitions of 3 s isometric forearm flexion maximal voluntary isometric contractions (MVICs) at EJ125 to set a perceptual anchor corresponding to RPE = 10. Finally, the subjects performed a brief (approximately 1 min), sustained, isometric task anchored to RPE = 8 at EJ125 to become familiarized with the testing and anchoring procedures. Finally, the subjects were familiarized to the post-test questionnaire (PTQ) and read the standardized PTQ instructions , age, height, and body mass of the subjects were recorded. In addition, the subjects were oriented to their testing position on the upper body exercise table (UBXT) of the calibrated isokinetic dynamometer  with the lateral epicondyle of the humerus of the dominant arm aligned with the lever arm of the dynamometer at EJES scale ,19,20 anES scale   was performed at EJ125 (RPEFT). During the sustained isometric task, the subjects were unaware of torque and elapsed time to avoid pacing strategies [During test visit 1, the subjects were positioned in accordance with the Cybex II user’s manual on the UBXT with the lateral epicondyle of the humerus of the dominant arm aligned with the lever arm of the dynamometer at EJ warm-up , followerategies . During rategies ,39. Furt125. Following the MVIC trials, the subjects performed a sustained, isometric forearm flexion task anchored to the torque (TRQFT) produced during the first 1 s of the RPEFT. This was conducted so that both fatiguing tasks began at the same initial torque value. During the TRQFT, the target torque was displayed on a computer screen to allow the subjects to track their torque output throughout the sustained, isometric task. The TRQFT was sustained to task failure, which was defined as the time point at which the subjects could no longer maintain the target torque despite strong verbal encouragement. Upon task failure, the task was terminated and the TTF was recorded. Immediately after task failure, 2 repetitions of 3 s post-test MVICs were performed in a manner identical to the pre-test MVICs, and the PTQ was completed. Strong verbal encouragement was provided for all MVIC trials.During test visit 2, the positioning on the UBXT and arm alignment for the subjects were identical to test visit 1. Once positioned, the subjects performed the standardized warm-up , followeThe PTQ  was provDuring the testing visit, bipolar (30 mm center-to-center) EMG electrodes  were attached to the BB of the dominant arm based on the recommendations of the Surface Electromyography for the Non-Invasive Assessment of Muscles . A refert-test was used to examine the mean differences between anchor schemes (RPEFT vs. TRQFT) for the TTF values. The mean differences for the pre-test and post-test MVIC, EMG AMP, and NME values by anchor scheme were determined with a 2 (time: pre-test vs. post-test) × 2 (anchor scheme: RPEFT vs. TRQFT) repeated measures ANOVA. Finally, to determine the mean differences between the average values for the five item  6-point scale PTQ, the Wilcoxon Signed Rank Test [t-tests. Effect size was reported as t-tests, respectively. A p-value ≤ 0.05 was considered statistically significant and all the data were reported as mean ± SD. All calculations and statistical analyses were carried out in IBM SPSS v. 28 .In Ref. , a depenank Test  was utilp = 0.006, d = 1.363) greater than the TRQFT (174.9 ± 85.6 vs. 65.6 ± 68.0 s). For MVIC, there was no significant  greater than the post-test MVIC values (23.7 ± 5.5 vs. 17.9 ± 5.1 N·m), and that the pre-test MVIC values from the RPEFT visit were significantly  greater than the pre-test MVIC values from the TRQFT visit (21.9 ± 5.9 vs. 19.6 ± 4.9 N·m). For EMG AMP, there was no significant  greater than the post-test NME (1.00 ± 0.00 vs. 0.76 ± 0.15).The results for the TTF, MVIC, EMG AMP, and NME values are presented in Z = −1.000, p = 0.317), FM fatigue , HM fatigue , loss of motivation , or loss of focus . The frequency of responses for each item is presented in Five separate Wilcoxon Signed Rank Tests were used to examine the average differences between the RPEFT and TRQFT for the five-item response scores. There were no significant differences between the RPEFT and TRQFT response scores for BB fatigue , extracellular potassium (K+), and magnesium (Mg) [+) in the interstitial space [These results indicated that there were no fatigue-induced changes in EMG AMP  followinium (Mg) ,64,65,66ium (Mg) . Alternaal space  that caual space ,68. It hal space  that cenal space ,48, theral space , as wellThe five PTQ items in the present study were designed to assess the locations and magnitudes of perceived sensations that potentially contributed to reaching the STL and, therefore, terminating the fatiguing tasks . The perA potential limitation of the present study was the inability of the sample size to detect significant mean differences for EMG AMP. Furthermore, it has been suggested  that exeIn summary, the present study examined the influence of an anchor scheme (RPEFT vs. TRQFT) on changes in performance fatigability and neuromuscular responses, as well as PTQ responses that represented factors associated with perceived fatigability that contributed to the decision to terminate the task. The present findings indicated that the RPEFT had a longer TTF versus the TRQFT, which was likely due to the ability to consciously derecruit motor units and reduce torque. Furthermore, there were similar fatigue-induced decreases in MVIC following the RPEFT and TRQFT, which may have indicated that subjects reached the same individual STL for both tasks. In addition, given the lack of changes in EMG AMP following the RPEFT and TRQFT, we postulated that this may have reflected no change in muscle excitation associated with central fatigue and that it was due to peripheral fatigue that resulted in excitation–contraction coupling failure as evidenced by decreased NME. Finally, although the PTQ responses indicated no mean differences between the anchor schemes, there were substantial interindividual differences in the responses. It was hypothesized that the perceived sensations from the BB, FM, and HM likely reflected peripheral sensory feedback via group III/IV afferent neurons. For loss of motivation and loss of focus, we hypothesized that these items were likely mediated by a single or a combination of peripheral and central factors involved with feedback and/or feedforward processes in higher brain centers. The present findings provide a foundation for future studies to assess the contributing performance-related factors and psychological factors to the decision to terminate the task. Additional studies should assess other psychological factors, such as overall perceived fatigue, affective valence, and pain perception, to determine if they contribute to the decision to terminate a task anchored to RPE or torque. Future studies should also utilize the interpolated twitch and potentiated twitch amplitude techniques, along with MMG MPF, and, potentially, decomposition techniques to examine the relative contributions of central and peripheral mechanisms to MVIC loss following sustained tasks anchored to a constant RPE and torque.


Body weight, height, waist circumference, as well as systolic and diastolic blood pressure were measured. Weekly food consumption patterns were assessed using 1 day 24 h dietary recall (24HR), 1 day weighed food record (WFR), and 5 day food tally. Linear programming (LP) analysis using WHO Optifood software was used to identify problem nutrients and develop FBRs. The identified nutrient gaps were inserted in the nutrient-dense menu for the worksite canteen. Obesity, central obesity, and hypertension were reported in 64.5%, 48.4%, and 3.2% of the workers. Calcium, folate, total PUFA, n-6 PUFA, and dietary fiber were identified as problem nutrients. The FBRs can improve the intake of problem nutrients from 20% of recommended nutrient intake (RNI) in the nonoptimized diet to 50–70% RNI in the optimized diet, while controlling the intake of sodium and saturated fat within an acceptable range. The remaining nutrient gaps  were inserted into the 14-day modified canteen snack menu. This study provides initial evidence that a combination of FBRs and a modified canteen menu can optimize the diet of the workers. Further studies assessing the effectiveness of the developed FBRs and modified menus are needed.The objective of this study is to identify problem nutrients and to develop food-based recommendations (FBRs) and nutrient-dense menus based on the nutrient gaps. This study was conducted among male workers ( The workplace meal program is an important investment in malnutrition, obesity, and chronic disease prevention . RecentlCompared to general workers, there is an increased risk for obesity, high blood pressure, high fasting blood glucose, and high cholesterol level among workers in oil and gas settings ,8, due tOil and gas industries invested in worksite wellness programs designed to improve employees’ overall health and well-being, including food and nutrition ,15,16. Hn-6 fatty acid, zinc, iron, and fiber) [To improve the quality of workers’ diets, linear programming (LP) can be used to find the optimal combination of daily food patterns for a specific population under various constraints. In LP, the goal is to meet energy and nutrient requirements while keeping the constraints, i.e., minimizing deviation from existing diets and  low cost ,20. In gd fiber) .n-3 and n-6 polyunsaturated fatty acids (PUFAs), Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), and dietary fiber, while at the same time controlling the intake of sodium, total fat, and saturated fat within the acceptable levels.The LP approach in this study will be applied to the worker dietary pattern to identify the problem nutrient, find the optimal combination of daily foods reflected as food-based recommendations (FBRs), and a nutrient-dense canteen menu to improve the dietary quality of oil and gas workers who are predominantly overweight and have dyslipidemia. The nutrients of interest to be optimized were Using a cross-sectional study design, a dietary survey using a 1-day weighed food record, 24 h dietary recall, and 5-day food tally were conducted at the oil and gas worksite between February and March 2020. The cost of food per 100 g edible portion was obtained from the worksite canteen procurement.This study was conducted in East Kalimantan Province, Indonesia. The province was chosen as it recorded the highest availability of oil and gas worksites. There were 12 sites located in East Kalimantan from a total of 82 sites across the country . RecruitThe site of oil and gas was generally divided into two types based on the geographical location, which could be onshore (land-based) or offshore (platform located at the sea) . CompareFood was provided by the company in the worksite canteen in a free-flow buffet style. This covers the mealtime of breakfast, lunch, dinner, and coffee breaks for the offshore site, but only breakfast on the onshore site. Lunch and dinner on the onshore site were pre-ordered with three choices: (1) traditional Indonesian cuisine, (2) western, and (3) plant-based menu. Supper could be requested for night-shift workers at both sites. The worker was restricted from eating any food outside the canteen; however, since the onshore site was surrounded by residential areas, they could easily go out to eat in nearby food stalls or make a delivery order, unlike the isolated offshore setting.Participants were male oil and gas employees aged 30–49 years old with at least one year duration of employment and were working on shift for at least one week before the 7-day dietary survey. Workers diagnosed with a history of cardiovascular and/or chronic kidney diseases were excluded.A list of all workers was obtained from each company’s health clinic. A total of 104 workers were eligible for this study, 52 workers were on shift, and from those 17 workers stayed less than seven days during data collection periods. In total, 35 oil and gas workers were recruited. Four respondents were excluded from the analysis due to incomplete record days (2) and under-reporting (2). Finally, 31 subjects were included in the analysis, consisting of 13 offshore workers and 18 onshore workers.Information on socio-demographic characteristics, sleep duration, and smoking habits was collected by the enumerators through face-to-face interviews. Participants were asked to record their activities using Bouchard physical activity records on two non-consecutive working days and one day during the weekend. The activity was recorded based on the intensity category with a score in the range of 1–9, with a higher score indicating a heavier intensity. The metabolic equivalent (MET) values were calculated, and average MET values were used to estimate physical activity level (PAL) . The resTwo repeated measurements of body weight, body height, waist circumference, and systolic and diastolic blood pressure were measured, and the average value was used in the analysis. The body weight was measured using the SECA 876 weighing scale and recorded to the nearest 0.1 kg. SECA 206 mechanical measuring tape was used to measure the height to the nearest 0.1 cm. Waist circumference was measured using a SECA 201 measuring tape to the nearest 0.1 cm. Systolic and diastolic blood pressure were measured using a digital sphygmomanometer. All measurements were taken by trained field enumerators with the standard procedure following the protocol of the WHO STEPwise approach to non-communicable disease risk factor surveillance .Weekly food consumption was assessed using 1 day 24 h dietary recall (24HR), 1 day weighed food record (WFR), and 5 day food tally. The assessment of 24HR was conducted on the first day of data collection, the multiple-pass approach was chosen to reduce the recall bias ,29. RespThe details of food preparation were observed directly at the company’s kitchen, and documentation of food recipes was recorded and confirmed with the head chef and/or nutritionist. The salt intake was recorded together with WFR, including (1) the weight of salt and sauces added at the cooking steps and salt added by the worker at the table, (2) salt from processed food obtained from the food label, and (3) in case of eating outside the canteens, salt reference value from Indonesian Ministry of Health was used to calculate the estimated salt absorption for all condiments ,32. DataInformation on the food availability and cost was obtained from the document of delivery order of the worksite canteen to the local supplier. The price was averaged between onshore and offshore companies. Data are expressed as cost  per 100 g edible portion.www.panganku.org) [https://fdc.nal.usda.gov/) [Food nutrient values were obtained from the Indonesian Food Composition Table (nku.org) , except da.gov/)  with watda.gov/) .Nutrient requirements were acquired from Indonesian Recommended Nutrient Intake (RNI) for males aged 30–49 years old . The rec2) is used [Energy requirement was calculated using the equations for estimating Basal Metabolic Rate (BMR) from body weight for males ages 30–49 years old available in the Optifood application multiplied by PAL. The physical activity level of active or moderately active was chosen given the occupational activities of oil and gas workers . Ideal b is used . Based op-value < 0.05 level.Data were entered using EpiData version 3.1. One week’s food consumption data , 1 day weighed food record (WFR), and 5 day food tally) were prepared using the NutriSurvey program. Statistical analyses were completed with the IBM SPSS Statistic version 21. Data are presented as mean ± SD for normally distributed variables and the median (Q1–Q3) for non-normally distributed variables. Statistical significance was determined at a Summary statistics from the one-week food consumption data , 1 d weighed food record (WFR), and 5 day food tally), including a list of foods consumed, food serving sizes, and frequency of consumption, were used to define the linear programming model parameters. Food groups and sub-groups were classified based on the Optifood classification. The final LP model parameter consists of foods consumed by at least 5% of workers and nutrient-dense foods consumed by <5% of the worker but has the potential to be promoted for consumption. Food serving size was defined as the median serving size of each food item . The minimum and maximum frequency were defined as the 5th and 95th percentile for each food item, food sub-group, and food group, respectively. All data were imported into the WHO Optifood Software (version 4.0.14.0).All three Optifood modules were used during the LP analysis. Module I was operated to verify whether the solution was feasible to develop realistic diet models within the actual dietary data.Module II (Draft recommendation) was used to identify the two best diets for achieving nutrient goals. This includes (1) one best diet within the population’s average food pattern (FP), and (2) one best diet with a larger range of food patterns that may deviate from average intake but still within the observed value, called no food pattern (NFP). Problem nutrients and potential nutrient-dense food items, food subgroups, and food groups to be promoted were identified through this module to help design alternative sets of FBRs. Problem nutrients were defined as nutrients that did not fully satisfy the RNI in the two best diets.In Module III (Test recommendation), linear programming was used to compare alternative sets of FBRs for nutritional adequacy and cost. During the LP analysis, original slots for the 14 nutrients available in the software were modified with the inclusion of SFAs, PUFAs, omega 6, omega 3, EPA + DHA, fiber, and sodium. The nutrients that were replaced included iron, zinc, thiamine, riboflavin, niacin, vitamin B-6, and vitamin A RE, which were found to be adequate in this population of male oil and gas workers.Two series of analyses were conducted using the Optifood software tool. In the first series of analyses, the actual portion size was used for the LP input model parameter. Considering that dietary fiber consumption was reported as very low in this population, the second series of analysis includes the prescribed portion.The FBR which (1) had the highest %RNI worst-case scenario for protein, calcium, vitamin C, folate, vitamin B-12, vitamin A RAE, PUFAs, omega 6, omega 3, EPA + DHA, and fiber, (2) did not exceed ≥100% RNI of total fat, SFAs, and sodium, and (3) had the lowest cost was selected as the final FBR . There wEthical approval was obtained from the Ethical Committee of the Faculty of Medicine, Universitas Indonesia No 182/UN2.F1/ETIK/PPM.00.02/2020 issued on 20 February 2020. All participants signed the written informed consent.Characteristics of the study groups are presented in p < 0.05) and diastolic blood pressure  as compared to the onshore counterparts. All the respondents had 12 h long working hours with a 14/14 schedule. Twenty workers (64.5%) were categorized as obese (BMI ≥ 25 kg/m2). The average body mass index (BMI) was 25.4 ± 3.2 kg/m2 and 15 workers (48.4%) had central obesity. Twenty-one of thirty-one workers did not have adequate sleep. The physical activity levels (PALs) of 48.4%, 25.8%, and 25.8% of the workers fell into the sedentary, moderate, and vigorous PALs, respectively.The offshore worker reported a higher total cholesterol level  and saturated fat . Higher cholesterol intake was observed in the offshore group .Including foods consumed by at least 5% of the workers plus the nutrient-dense foods in each offshore and onshore group, 173 and 176 food items identified among each group, respectively. Combined food items between groups resulted in 201 food items, which consisted of 15 food groups and 55 food subgroups, and their weekly frequency of consumption was presented in p < 0.01). The most consumed fruits were watermelon and papaya (81% for each). Higher weekly consumption of processed meat was reported in the offshore group . Side dishes were cooked using palm oil, margarine, and coconut oil with a median frequency of added fat consumption 32 times per week (4–5 times daily). Salt was the most consumed food in the spices and herbs group with a frequency of 14–42 times/week (2–6 times daily). Salt was used as seasoning mainly when cooking animal products, legumes, and vegetables. Aside from mealtime, the respondents consumed snacks during break time. The snacks provided in the canteen consist of pancakes, pastries, cakes, fruits, and one-dish meals. Sweetened bakery products were consumed by 13–35% of the workers. The median weekly consumption of added sugar was 12 times per week with a median portion size of 7 g.Offshore workers consumed fruits less frequently  but could be achieved in the best-case scenario (Module III). Total PUFAs, n-6 PUFAs, and dietary fiber were categorized as absolute problem nutrients.Given the similar issues experienced by offshore and onshore oil and gas workers, including excess body weight, high intake of total fat, saturated fat, and sodium, as well as low intake of dietary fiber, the LP analysis was performed with combined food lists and food patterns. n-6 PUFAs, and dietary fiber were categorized as absolute problem nutrients. This scheme did not increase the cost of the food and resulted in fewer problem nutrients compared to the actual portion size. This scheme was selected to be tested in Module III to identify the alternative sets of FBRs.The second run on whole LP analysis was performed using the prescribed portion size. Using this scenario, dietary fiber was identified as a partial problem nutrient, and on the other hand, total PUFAs, n-6 PUFAs, and dietary fiber, the best diet developed by LP significantly increased %RNI from the baseline non-optimized diet. The gaps between 65% of RNI with minimized %RNI in the selected FBR were inserted into the nutrient-dense canteen snack menu. The list of the 14-day modified canteen snack menu, nutrient content, and cost are presented in Box 1Recommended messages of food-based recommendationsAt least 5 servings/week of whole grain productsConsume 3 main meals in a day consisting of grain foods, including:At least 8 servings/week of fish, including 4 servings/week of MackerelAt least 5 servings/week of poultryConsume 2 servings/day of meat, fish, or poultry, including:Consume 1–2 serving/day of legume, nuts, or seedsAt least 7 servings/week of dark green leafy vegetableConsume 2.5 servings/day of vegetables, including:At least 5 servings/week of vitamin C sources fruitConsume 1.5 servings/day of fruits, including:Limit fried food or foods cooked with margarine, butter, and coconut milk to a maximum of 3 servings/dayLimit the usage of added salt to a maximum of ½ teaspoon/dayRecommended portion size/serving1 serving of brown rice milled = 100 g (cooked weight)1 serving of fish = 75 g (wet weight)1 serving of meat/poultry = 40 g (wet weight)1 serving of tempeh = 50 g (cooked weight)1 serving of peanut = 20 g (wet weight)1 serving of vegetables = 100 g (wet weight)1 serving of fruits = 80 g (wet weight)1 serving of vegetable oil/butter/margarine = 5 g1 serving of coconut milk = 30 g½ teaspoon of salt = 1 gn-6 PUFAs, and dietary fiber as problem nutrients in the diet of oil and gas workers. Furthermore, we also addressed the remaining nutrient gaps by modifying the canteen snack menu. The findings from this preliminary study show that the combination of both FBRs and a modified canteen menu has great potential to ensure workers’ nutrient adequacy.To the best of our knowledge, this study is the first to identify the problem nutrients and develop FBRs using the LP approach for a specific population of oil and gas workers. The LP analyses identified calcium, folate, total PUFAs, 2), i.e., 64.5%. This was comparable to the previous studies in oil and gas workers in Indonesia and Italy, i.e., 49.5% and 62.4% [The present study observed a high prevalence of overweight and obesity among oil and gas workers . Some observed issues related to the food provision and cooking methods in the canteen were overuse of oil, salt, and sauces; most side dishes were prepared using deep-fried cooking, stir-fried with ketchup, cooked with coconut milk, or with butter and margarine. Snack was mainly cake and bakery which may contribute to the higher intake of saturated fat and sugar. We found only one study reporting dietary patterns of offshore workers in Norwegians which found that meat, vegetables, fresh fruits, seafood (shellfish), French fries, eggs, cream, and ice cream were important components of the diet of workers. The study highlighted that their diet pattern may contribute to the development of CVD among oil and gas workers .The above findings strengthen the statement that, in workplaces where employees’ meals are provided by the company, a poor design of the meals may lead to negative consequences for their health. Food-based recommendations developed in this study can be beneficial to improve the food provision since they were developed from the actual weekly dietary patterns of the workers. LP analysis found that PUFAs, omega 6, and dietary fiber were absolute problem nutrients. These nutrients were known to be associated with dyslipidemia and metabolic syndrome (MetS) ,46,47,48n-3 PUFAs. The consumption of a minimum of eight servings per week of any type with half of it being fatty fish may contribute to ≥50% of RNI for n-3 PUFAs, EPA, and DHA (FBRs #1).Using the LP approach, the final FBRs can achieve the recommended intake of vitamin C, omega 3, EPA + DHA, folate, vitamin B12, vitamin A, and omega 3 intakes for males aged 30–49 years old. Adherence to these FBRs will also ensure the intake of sodium and saturated fat within the recommended value. However, after increasing the intake of problem nutrients from about 20% RNI in the non-optimized diet to 50–70% RNI in the optimized diet, it was still below 65% RNI of PUFAs, omega 6, calcium, and dietary fiber (nutrient gaps). We therefore use these nutrient gaps to guide the modification of the canteen menu, i.e., the ingredients and the amounts. For example, although the fiber intakes of the workers were very low, some choices of whole grains were available in the canteen such as brown rice, oatmeal, and muesli. Therefore, the FBRs promoted the consumption of whole grain products a minimum of 5 times/week. This can increase the %RNI of dietary fiber from 9.2% to 23.5% in the worst-case scenario. Another example is shifting the type of fish to fatty fish as a source of While previous LP studies suggested fortification and supplementation to fill the nutrient gaps  ,49, the To date, the LP analysis using Optifood software has been primarily used to address undernutrition problems in infants and young children or women of reproductive age and adolescent girls ,49,50. Tn = 104), which showed 77.4% overweight and obesity prevalence. Further intervention studies are needed to test the effectiveness of FBR promotion and nutrient-dense menu to reduce overweight/obesity and dyslipidemia amongst oil and gas workers.The main limitation of this study was its relatively small sample. Nevertheless, the respondents included in this study have similar characteristics to all workers based on the 2019 medical records (The oil and gas workers reported poor dietary patterns including a high intake of total fat, saturated fat, and sodium, with a low intake of dietary fiber that may contribute to overweight and dyslipidemia. This study showed that a combination of FBRs and a modified canteen menu have great potential to optimize the diet of the workers. Further studies assessing the effectiveness of the developed FBRs and modified canteen menus to prevent overweight/obesity in workplace settings are needed.


This study aimed to identify the current risk factors for coronavirus disease 2019 severity and examine its association with medication use.We used data from a large United States electronic health record database to conduct an anonymized cohort study of 171,491 patients with coronavirus disease 2019. The study was conducted from January 1, 2020, to August 27, 2021. Data on age, race, sex, history of diseases, and history of medication prescriptions were analyzed using the Cox proportional hazards model analysis to calculate hazard ratios for hospitalization and severe risk.P < 0.001) and critical care . In contrast, patients with hyperlipidemia had a reduced risk. However, patients with hyperlipidemia who were not taking statins had a significantly increased risk of hospitalization . Sodium-glucose cotransporter-2 inhibitors, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, glucocorticoids, and statins significantly reduced the risk of hospitalization and critical care. The risk of hospitalization and critical care increased in patients of all ethnicities with type 2 diabetes. The factors that significantly increased the risk of hospitalization in all regions were older age, hypertension, chronic obstructive pulmonary disease, and cardiovascular disease.Factors that increased the risk of hospitalization and critical care were age ≥ 65 years, male sex, type 2 diabetes, hypertension, interstitial pneumonia, and cardiovascular disease. In particular, age ≥ 65 years significantly increased the risk of hospitalization (hazard ratio, 2.81 ; This study identified factors that increase or reduce the risk of severe coronavirus disease. The provision of appropriate drug treatment and modification of lifestyle-related risk factors may reduce coronavirus disease severity. Studies on the risk factors for severe coronavirus disease 2019 (COVID-19) have been conducted worldwide in patients with varying demographic characteristics. Older age, male sex, obesity, and certain diseases such as hypertension and diabetes have been reported as risk factors for severe disease . SeveralSeveral studies have shown that drug therapy for the underlying disease is not associated with a substantial increase in the risk of COVID-19 severity, suggesting that metformin, sodium-glucose cotransporter-2 (SGLT2) inhibitors, and beta blockers may improve the conversion , 9. TherThis study used medical and pharmacy claims data and electronic medical records from the Healthjump database  provided by the COVID-19 Research Database Consortium. All personal information in this database is anonymized. The Healthjump configuration tables consist of demographic (patient background), diagnosis (diagnosis name), medication, and procedure (treatment) data variables. Data were extracted by SQL using Snowflake .2 or BMI > 50 kg/m2; or (4) had suspected COVID-19, but no confirmed diagnosis. Data obtained from the EHR included date of diagnosis, race , ethnicity , region , hospitalization and critical care status, age, sex, and BMI . In addition, data on history of diseases that are considered to be significant risk factors for COVID-19 severity  and prescription history (whether or not prescribed in the year prior to diagnosis) of drugs to treat these conditions were included. This analysis was conducted based on the methodology used in previous studies [From January 1, 2020, to August 27, 2021, in the United States, 171,491 patients who had (1) a diagnosis of COVID-19  and (2) were aged 20 years or older were included in this study. Patients were excluded if they (1) were younger than 20 years of age; (2) had missing race and sex; (3) had a body mass index (BMI) ≤ 15 kg/m studies , 13.https://www.census.gov). The District of Columbia  is not part of any state, but is considered Southern; therefore, it was classified as Southern in this study.Each state was classified into four regions according to the United States Census Bureau regional classifications  fourth edition (CPT-4) codes and Healthcare Common Procedure Coding System (HCPCS) codes used for reimbursement in the United States were used as references. Patients with a code of hospitalization  were defined as hospitalized, those with a code of critical care  were defined as critical care, and patients without either of the above codes were defined as having no admission. The oldest code was used in place of the CPT4 and HCPCS codes, for diagnosis in cases where the same code or codes before and after diagnosis were consecutive or overlapping.We used these codes for analysis if the patient had these codes for less than 30 days after being diagnosed with COVID-19. Sub-analyses were conducted for each region in the United States and race, with the objective of determining characteristics by race and region.P ≤ 0.2. The significance level for multivariate analysis was set at P < 0.05. The same analysis was performed for hospitalization and critical care by race and region.Statistical analyses were performed using STATA 16.0 . Risk factors for hospitalization and critical care were analyzed using Cox proportional hazards model analysis, and hazard ratios (HRs) were calculated. Univariate analysis was performed with the extracted codes (presence or absence) set as the independent variables; multivariate analysis was performed for factors with 2. The number of hospitalized patients and those who received critical care services were 5,812 (3.4%) and 1,704 (1.0%), respectively. The number of patients by race was White, 92,184 (53.8%); Black, 21,052 (12.3%); and Asian, 1,440 (0.8%). The number of patients per region was 19,909 in the Northeast (11.6%), 10,612 in the Midwest (6.2%), 100,574 in the South (58.6%), and 40,299 in the West (23.5%).The clinical characteristics of the patients, number of patients with each disease, and number of patients using each drug for each disease are shown in Table P < 0.001) and critical care . In contrast, SGLT2 inhibitors, ACE inhibitors, ARBs, glucocorticoids, and statins significantly reduced the risk of hospitalization and critical care. In our analysis, hyperlipidemia also significantly reduced the risk of hospitalization and critical care .The results of the multivariate analysis based on the univariate results for the risks of hospitalization and critical care are shown in Fig. As the risk was reduced in patients with hyperlipidemia, a detailed analysis was performed.P < 0.001) for hospitalization in patients not prescribed statins. Patients with hyperlipidemia who were not taking statins had a significantly increased risk of hospitalization   inhibitors, and glinides. Differences in sample size may have affected the results. Khunti et al. reported that they found no association between patients using glinide preparations and COVID-19-related deaths . To deteIn contrast, there are reports that sulfonylurea, which significantly lowered the HR for hospitalization, has no effects on mortality due to COVID-19 . We beliAmong antihypertensive drugs, ACE inhibitors and ARBs significantly reduced the HR. Both of these agents are involved in the renin-angiotensin system and have mechanisms that inhibit the action of angiotensin II. These drugs have been reported to upregulate ACE2, the infection receptor for COVID-19 , and couAmong the drugs used to treat respiratory diseases, steroids resulted in a significantly lower HR. Yochai et al. reported that inhaled steroids exert anti-inflammatory effects in the lungs and reduce ACE2 and transmembrane protease, serine 2 expression in bronchial epithelial cells . This su2 stimulants also significantly reduced the HR for critical care. Yamaya et al. reported that in cold coronavirus (HCoV-229E), β2-stimulants suppressed viral receptor expression in cells [Betain cells . FurtherExcluding patients who were prescribed statins resulted in a significantly higher HR for hospitalization in patients with hyperlipidemia, but no significant difference in the HR for critical care. Previous studies have suggested that hyperlipidemia is associated with severe COVID-19 . PatientIn elderly men, diabetes and cardiovascular disease tended to increase the HRs in both region-specific and race-specific analyses. In contrast, ACE inhibitors tended to lower the HR. These could be risk factors for severe disease or factors that reduce the risk of severe disease, regardless of the region of residence or race.The analysis by region showed a large variation in the number of patients, and it was not possible to determine the characteristics of differences in the risk factors for severe disease in different regions. In the race-specific analysis, non-Hispanic Black and Hispanic patients showed different trends from the other groups.Risks of hospitalization and critical care were highest among non-Hispanic Black patients. non-Hispanic Black patients have been reported to be at significantly higher risk of death from COVID-19 than non-Hispanic White patients or Asian patients , suggestIn addition, a unique feature of the results for non-Hispanic Black patients was that the item that most significantly reduced the HR for hospitalization was a SGLT2 inhibitor. Other racial groups did not show significant differences in SGLT2 inhibitor use, with only non-Hispanic Black patients exhibiting significantly lower results. Clements et al. reported that Black individuals with diabetes have a higher incidence of chronic kidney disease (CKD) comorbidity . ChronicHypertension was detected as a COVID-19 severity factor in the overall multivariate analysis; however, when analyzed by race, a no significant association was found Hispanic and non-Hispanic Asian patients. No significant association was observed in non-Hispanic Asian patients due to the small population size. Hispanic individuals have a lower prevalence of hypertension in the United States than do White and Black individuals. Hispanic individuals have been reported to have lower mortality rates from cardiovascular diseases than that of White individuals, suggesting that Hispanic persons differ from other racial groups in their risk for cardiovascular diseases . TherefoThe present study has some limitations. First, the underlying diseases of the patients were extracted based on their EHRs and did not reflect the stage or progression of their disease. Second, only diagnosed infections were included in the analysis; therefore, the impact of reinfection was not considered. Non-symptomatic infections that were not included in the database were also excluded. Third, although it was necessary to investigate the impact of vaccination to improve the accuracy of the data, missing information prevented identification of patients who were not vaccinated. Furthermore, vaccinations are administered rapidly at venues and pharmacies, making it difficult to link the information in this database. Fourth, this study did not examine the effects of malignancy, cerebrovascular disease, CKD, human immunodeficiency virus infection, immunodeficiency, immunosuppressive drugs, pediatric disease, or pregnancy. Fifth, because drug information in this case was analyzed based on the drug prescription history, it was not possible to determine whether a drug was actually administered to the patient. Finally, we did not examine the impact of multiple risk factors for severe disease or factors that reduce the risk of severe disease. Additionally, the present analysis was not conducted separately for each specific drug or disease management status. Further studies are needed to determine which patients are more likely or less likely to develop severe disease.One significant contribution of our study is the examination of ethnicity and race as risk factors for COVID-19 severity. We provide new findings regarding disparities in hospitalization and ICU admission rates among racial and regional groups within the US population. However, it is essential to note that our analysis may not cover all possible configurations of ethnicity and race in the United States, and the results should be interpreted with caution. In a cohort analysis of 171,491 COVID-19-positive patients from a large United States electronic health record (EHR) database, we observed that several factors increased the risk of hospitalization and critical care. These factors included age ≥ 65 years, male sex, type 2 diabetes, hypertension, interstitial pneumonia, and cardiovascular disease. In contrast, we found that certain medications, such as SGLT2 inhibitors, ACE inhibitors, ARBs, glucocorticoids, and statins, significantly reduced the risk of hospitalization and critical care. Furthermore, our study revealed that type 2 diabetes increased the risk of hospitalization and critical care across all ethnicities. Additionally, age ≥ 65 years, hypertension, COPD, and cardiovascular disease significantly increased the risk of hospitalization in all regions of the United States. These findings underscore the importance of appropriate drug therapy and management of lifestyle-related diseases in reducing the severity of COVID-19.