Exposure to environmental heavy metals may pose a risk factor for developing preeclampsia (PE) modified through intervention. This case-control study aimed to investigate the association between serum heavy metal concentrations and PE in pregnant women and whether hormones served as mediating factors in the impact of heavy metals on PE. From October 2020 to 2022, 160 patients with PE and 160 pregnant women with normal deliveries were recruited at Dongguan Songshan Lake Central Hospital. Serum concentrations of manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), lead (Pb), β-human chorionic gonadotropin (β-hCG), progesterone (P), estradiol (E2), testosterone (T), cortisol (Cort), and cortisone (Cor) were measured. Logistic, restricted cubic splines, weighted quantile sum and multivariate linear regression models were employed to account for different aspects and explore the relationships among heavy metals, hormones, and PE. Mediation model analysis was performed to assess the role of hormones in mediation. The median concentrations of Mn, E2, and Cort were lower in the PE group than in the control group. The median concentrations of Cu, Zn, β-hCG, and T were higher in the PE than in the control. Mn, E2, and Cort showed negative associations with PE, while Cu, Zn, β-hCG, and T demonstrated positive associations, as determined through logistic regression. Mn, Cu, and Zn displayed linear dose-response relationships with PE. Zn and Cu had high weights in the positive association model of mixed heavy metal exposure with PE. The mediation analysis revealed that serum E2, P, T, Cort, and Cort/Cor might be potential mediators of the association between heavy metals (Mn, Cu, and Zn) and PE.

BACKGROUND: The causal association and biological mechanism linking serum 25-hydroxyvitamin D to stroke risk lacks epidemiological evidence.
OBJECTIVE: This study aimed to investigate the association between 25(OH)D concentration and stroke risk as well as the potential mediating factors.
METHODS: The community-based prospective community-based cohort study, the Chin-Shan Community Cardiovascular Cohort, was conducted from 1990 to December 2011, with external validation using a two-sample Mendelian randomization (MR) study.
METHODS: A total of 1,778 participants with serum 25-hydroxyvitamin D data were enrolled.
METHODS: In the CCCC observational study, the outcome was ascertained as stroke, while in the two-sample MR study, it was defined as ischemic stroke. Causal effects were estimated using restricted cubic spline analysis, COX proportional hazard ratios, mediation analysis, and two-sample MR.
RESULTS: Over 12 years (21,598 person-years) of follow-up, 163 participants (9.17%) developed stroke. Higher 25(OH)D concentrations were associated with lower stroke risk (hazard ratio: 0.64; 95% confidence interval, 0.43-0.96) after full-model adjustments. Mediation analysis showed a significant association between 25(OH)D concentration and stroke risk mediated by hypertension in unadjusted models (mediation percentage 23.3%, p=0.008) that became non-significant in full models (mediation percentage, 15.5%; p=0.072). Two-sample MR confirmed a significant inverse association between genetically determined 25(OH)D and stroke risk (IVW OR: 0.92; 95% CI: 0.85-0.99; p=0.036). However, hypertension had an insignificant mediating role in the Mendelian randomization study.
CONCLUSIONS: Higher 25(OH)D levels are linked to reduced stroke risk, potentially mediated by hypertension. Prioritizing blood pressure management may improve stroke prevention in 25(OH)D-deficient patients.

BACKGROUND: The \"Healthy Mother Healthy Baby\" (HMHB) study is a phase three, single-blind randomized clinical trial conducted at Holy Family Hospital (HFH) in association with Rawalpindi Medical University (RMU). We aimed to examine the mediators of a specialized psychosocial approach based on Cognitive Behavioural Therapy principles, targeting pregnant women experiencing anxiety. The HMHB intervention was effective in treating perinatal anxiety symptoms and preventing future depressive episodes.
METHODS: The trial randomized participants into two arms: the HMHB intervention or Enhanced Usual Care (EUC), following World Health Organization guidelines. The HMHB intervention comprised strategies to strengthen social support networks, improving mother-baby bonding and strategies to deal with interpersonal conflicts, economic challenges, and societal gender preferences using cognitive and behavioural techniques and culturally resonant illustrations. Participants underwent rigorous data collection at three pivotal timepoints: baseline, third trimester, and 6-weeks postnatal. The primary outcome was anxiety symptom severity scores using the Hospital Anxiety and Depression Scale (HADS) at 6-weeks post-childbirth. Four potential mediators - social support, behavioural activation, perceived stress, and pregnancy experience - were assessed in the third trimester of pregnancy.
RESULTS: A total of 1200 participants were randomized to the HMHB and EUC arms. In the six-week follow-up time point, 379 participants remained in the EUC group, and 387 continued in the HMHB group. Post-intervention, HMHB participants displayed significant improvements in postnatal anxiety and depression scores. Mediation analyses revealed social support and pregnancy hassles as significant mediators of the intervention\'s effect on postnatal anxiety outcomes, while only social support emerged as a significant mediator for depression outcomes.
CONCLUSIONS: The HMHB intervention showed promising results in improving anxiety and depression scores among pregnant women. Significant mediation effects suggest the importance of targeting social support and managing pregnancy-related hassles for optimal intervention effectiveness.

BACKGROUND: Remnant cholesterol (RC) reportedly contributes to the development of diabetes mellitus. However, evidence on the relationship between maternal RC and the risk of developing gestational diabetes mellitus (GDM) during pregnancy is limited. This study aimed to assess the relationship between maternal RC and GDM risk during early pregnancy, and explore the potential pathways involved in the relationship between RC levels and GDM risk.
METHODS: From 2018 to 2021, a prospective birth cohort study was designed and carried out in China. The associations of maternal RC and other lipid parameters with GDM risk were estimated using logistic regression models and restricted cubic splines. Subgroup analyses were performed stratified by prepregnancy body mass index (pre-BMI), maternal age and gravidity. Mediation analyses were conducted to explore the mediating effect of some related factors on the relationship between RC levels and the risk of GDM.
RESULTS: A total of 33,018 pregnant women were included. The median RC level was 0.47 ± 0.20 mmol/L. The prevalence of GDM was 15.19%. As RC quartiles increased, the incidence of GDM increased substantially, reaching 19.24% for the highest quartile of RC (P < 0.001). Maternal RC in the first trimester was positively correlated with GDM risk (OR: 2.254, 95% CI: 1.943-2.615). Compared to the lowest RC quartile, higher RC quartiles were correlated with an increased risk of GDM, and the ORs (95% CIs) for Q3 and Q4 were 1.208 (1.101-1.325) and 1.489 (1.364-1.626), respectively. Moreover, a linear dose-response relationship was found for this association (P for all < 0.001, P for nonlinearity > 0.05) and was consistent across subgroups with different pre-BMIs, maternal ages and gravidities (all P values for interactions > 0.05). Furthermore, the correlation between RC level and GDM risk was partially mediated by pre-BMI (9.20%) and blood glucose level (-11.1%).
CONCLUSIONS: Higher maternal RC levels in the early stage of pregnancy was positively associated with an increased risk of developing GDM. This association was partially mediated by pre- BMI and blood glucose levels.

BACKGROUND: Previous studies have shown that physical activity (PA) and leisure sedentary behaviors (LSB, including leisure television watching) are linked to gastroesophageal reflux disease (GERD). However, the associations between PA/LSB and GERD remain controversial. In this study, we aimed to reveal whether these associations reflect causal relationships and reveal the potential mechanisms of these relationships using bidirectional and two-step Mendelian randomization (MR) analyses.
METHODS: We obtained genome-wide association study (GWAS) summary statistics for PA/LSB, four common risk factors (including cigarettes smoked per day, alcoholic drinks per week, triglycerides, total cholesterol) and GERD from published GWASs. A bidirectional MR analysis was performed to identify causal relationships between PA/LSB and GERD. Then, a series of sensitivity analyses were performed to verify the robustness of the results. Finally, a mediation analysis via two-step MR was conducted to investigate any effects explained by common risk factors in these relationships.
RESULTS: Genetically predicted per 1-SD increase in leisure time television watching significantly increased the risk of GERD in the bidirectional MR analysis (OR = 1.33; 95% CI: 1.14-1.56; P = 2.71 × 10- 4). Sensitivity analyses successfully verified the robustness of the causal relationship. Further mediation analysis showed that this effect was partly mediated by increasing cigarettes smoked per day, with mediated proportions of 18.37% (95% CI: 11.94-39.79%).
CONCLUSIONS: Our findings revealed a causal relationship between leisure television watching and an increased risk of GERD, notably, the causal effect was partially mediated by cigarettes smoked per day. These findings may inform prevention and management strategies directed toward GERD.

OBJECTIVE: This study explored the mediating effect of diabetes on the relationship between nonalcoholic fatty liver disease (NAFLD) and atherosclerotic cardiovascular disease (ASCVD).
METHODS: In this prospective community cohort study, 82 975 participants were enrolled, with the primary outcome being the incidence of new-onset ASCVD. Using the Cox proportional hazards model, the hazard ratio (HR) and 95% confidence interval (CI) for ASCVD occurrence were computed between NAFLD and non-NAFLD groups. The correlation between NAFLD and diabetes was assessed using a binary logistic regression model, and that between NAFLD, diabetes and ASCVD using a mediation model.
RESULTS: During follow-up, 9471 ASCVD cases were observed. Compared with individuals without NAFLD, those with NAFLD showed an increased ASCVD risk (HR: 1.424; 95% CI: 1.363-1.488; P < 0.001). Stratifying NAFLD based on metabolic subphenotypes revealed a higher ASCVD risk in the NAFLD combined with diabetes subgroup than in the non-NAFLD subgroup (HR: 1.960; 95% CI: 1.817-2.115; P < 0.001). NAFLD was positively associated with baseline diabetes (odds ratio: 2.983; 95% CI: 2.813-3.163; P < 0.001). Furthermore, NAFLD severity was positively correlated with diabetes risk. Mediation analysis indicated that diabetes partially mediated the effect of NAFLD on ASCVD incidence, accounting for 20.33% of the total effect.
CONCLUSIONS: NAFLD is an independent predictor of increased ASCVD risk, which may be slightly mediated by diabetes in patients with NAFLD. Evaluating NAFLD and diabetes may be crucial in the early screening and prevention of ASCVD.

BackgroundHepatitis C virus (HCV) infection is a systemic disease. However, the relative contribution of intrahepatic and extrahepatic diseases to mediating HCV-induced mortality is unclear, albeit critical in resource allocation for reducing preventable deaths. To this end, this study comprehensively quantified the extent to which intrahepatic and extrahepatic diseases mediate HCV-induced mortality.MethodsA community-based cohort study with >25 years of follow-up was conducted in Taiwan. HCV infection was profiled by antibodies against HCV and HCV RNA in participants\' serum samples. The cohort data were linked to Taiwan\'s National Health Insurance Research Database to determine the incidences of potential mediating diseases and mortality. We employed causal mediation analyses to estimate the mediation effects of HCV on mortality in relation to the incidences of 34 candidate diseases.ResultsIn 18,972 participants with 934 HCV infection, we observed that 54.1% of HCV-induced mortality was mediated by intrahepatic diseases, such as liver cirrhosis and liver cancer, and 45.9% of mortality was mediated by extrahepatic diseases. The major extrahepatic mediating diseases included septicemia (estimated proportion of HCV-induced mortality mediated through the disease: 25.2%), renal disease (16.7%), blood/immune diseases (12.2%), gallbladder diseases (9.7%), and endocrine diseases (9.6%). In women, hypertension (20.0%), metabolic syndrome (18.9%), and type 2 diabetes (17.0%) also mediated HCV-induced mortality. A dose-response relationship of HCV viral load was further demonstrated for the mediation effect.ConclusionBoth intrahepatic and extrahepatic manifestations mediated approximately a half of HCV-induced mortality. The mediation mechanisms are supported by a dose-response relationship of HCV viral load.

UNASSIGNED: While study approaches have been directly associated with students\' academic performance, learning environment factors may play a more indirect role. The aim of this study was (i) to assess learning environment factors as predictors of students\' average exam grades, and (ii) whether study approaches mediated associations between learning environment factors and exam grades.
UNASSIGNED: Three annual surveys (2017-2019) yielded data from a total of 263 Norwegian occupational therapy students. Learning environment factors were assessed with the Course Experience Questionnaire, and the Approaches and Study Skills Inventory for Students were used to assess study approaches. Linear regression analyses and mediation analyses were performed.
UNASSIGNED: Higher levels of \'student autonomy\' were directly associated with lower averaged grades whereas higher levels of \'appropriate workload\' were associated with higher averaged grades. There were statistically significant total indirect effects of \'clear goals\' and \'appropriate workload\' on grades; these effects occurred through the study approach variables. However, all learning environment variables showed one or more relationships with academic performance that was mediated by study approach variables.
UNASSIGNED: Learning environment variables appear to be complexly associated with academic performance, both directly and indirectly.

OBJECTIVE: This cross-sectional study aimed to explore the association between methyl mercury (MeHg) level and latent tuberculosis infection (LTBI) risk based on the data from National Health and Nutrition Examination Survey (NHANES 2011-2012).
METHODS: A total of 5243 participants with 20 variables were enrolled. The importance of these variables on TB infection was first ranked by XGBoost and Random Forest methods. Then the association between MeHg level and infection risk was evaluated by restricted cubic spline, threshold effect, and generalized linear regression analyses. We also explored the factors correlated with the difference in MeHg level and finally conducted a mediation analysis to assess the mediating effect of MeHg in LTBI.
RESULTS: 521 participants were experiencing the LTBI, and 12 variables showed the differences between infection and non-infection groups (all P < 0.05). Of them, MeHg presented the highest importance on the LTBI. Restricted cubic spline (RCS) next revealed a significant non-linear correlation of MeHg with LTBI (all P < 0.05). Adjusted regression models further indicated their independent association (all P < 0.05), and infection risk increased with the increase of MeHg (P for trend < 0.05). We also found a significant turning point, and their association was significantly observed when MeHg > 5.75 µg/L (P < 0.05). In addition, asthma history was related to the difference in MeHg levels between LTBI and non-LTBI groups. Mediation analysis found that MeHg level partially mediated the association of asthma and LTBI risk (all P < 0.05).
CONCLUSIONS: Our study identified MeHg as an independent risk factor for LTBI risk. Their causal relationship needs more investigation to verify.

UNASSIGNED: To investigate the impact of gut microbiota on osteoporosis and identify the mediating role of blood metabolites in this process.
UNASSIGNED: This two-sample Mendelian randomization (MR) study utilized summary level data from genome-wide association studies (GWAS). Gut microbiota GWAS data were obtained from the MiBio-Gen consortium meta-analysis (n=13,266), while osteoporosis summary statistics were sourced from the FinnGen consortium R9 release data (7300 cases and 358,014 controls). Metabolite data, including 1400 metabolites or metabolite ratios, were derived from a study involving 8,299 unrelated individuals. The primary MR method employed was the inverse variance weighted (IVW) method. Reverse MR analysis was conducted on bacteria causally associated with osteoporosis in forward MR. The gut microbiota with the smallest p-value was selected as the top influencing factor for subsequent mediation analysis. A two-step MR approach quantified the proportion of the blood metabolite effect on gut microbiota influencing osteoporosis. IVW and Egger methods were used to assess heterogeneity and horizontal pleiotropy.
UNASSIGNED: IVW estimates indicated a suggestive effect of family Christensenellaceae on osteoporosis (odds ratio(OR) = 1.292, 95% confidence interval(CI): 1.110-1.503, P =9.198 × 10-4). Reverse MR analysis revealed no significant causal effect of osteoporosis on family Christensenellaceae (OR = 0.947, 95% CI: 0.836-1.072, P =0.386). The proportion of the effect of family Christensenellaceae on osteoporosis mediated by circulating levels of 3,4-dihydroxybutyrate was 9.727%. No significant heterogeneity or horizontal pleiotropy was detected in the instrumental variables used for MR analysis.
UNASSIGNED: This study establishes a causal link between family Christensenellaceae and osteoporosis, with a minor proportion of the effect mediated by elevated circulating levels of 3,4-dihydroxybutyrate. Further randomized controlled trials (RCTs) are warranted to validate this conclusion.