New genetic loci link adipose and insulin biology to body fat distribution

The association between serum albumin levels and metabolic syndrome based on the NHANES and two sample Mendelian randomization study

Previous studies have shown that serum albumin levels are associated with a greater risk of metabolic syndrome (MetS). However, it is unclear whether this association is causal or only influenced by confounding factors, so further investigation is needed to determine the causal relationships. Researchers selected participants with serum albumin, metabolic syndrome, and related covariates from the National Health and Nutrition Examination Survey (NHANES) database for a total of 14,036 individuals, including 5483 individuals with MetS and 8553 individuals without MetS. The association of serum albumin levels with metabolic syndrome and its components was estimated using weighted multivariable logistic regression, with its nonlinearity being examined by restricted cubic spline (RCS) regression. Bidirectional two-sample Mendelian randomization (MR) analysis was performed using Genome-Wide Association Study (GWAS) data on serum albumin and MetS to assess the causal relationship between serum albumin levels and MetS and its components. The primary MR analyses were performed via an inverse variance weighting (IVW) approach. In addition, several sensitivity analyses were performed to assess the robustness of the results. The STROBE-MR checklist for the reporting of MR studies was used in this study. After confounder adjustment, when the serum albumin levels were analyzed as a continuous variable, the multivariable logistic analysis revealed a significant association between it and metabolic syndrome (OR: 1.032, 95% CI: 1.012-1.052). When the serum albumin levels were used as categorical variables, the adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for metabolic syndrome across higher serum albumin levels quartiles were 0.981 (0.842-1.143), 1.290 (1.115-1.492), and 1.244 (1.064-1.454) compared to the lowest quartile, respectively. In the forward MR study, the IVW method revealed that genetic predicted increased levels of serum albumin were positively correlated with metabolic syndrome (OR: 1.149, 95% CI: 1.016-1.299) and its components, including hypertension (OR: 1.130, 95% CI: 1.013-1.260) and triglycerides (OR: 1.343, 95% CI: 1.209-1.492). In the reverse MR study, the IVW method showed no significant causal relationship between MetS, hypertension, fasting blood glucose and HDL-C with serum albumin levels. The results from the NHANES and MR analysis have revealed a causal relationship between serum albumin levels and both metabolic syndrome and hypertension, indicating that elevated levels of serum albumin are a risk factor for these conditions. Our results provide new biomarkers for preventive and therapeutic strategies for metabolic syndrome.

Genetic Links Between Metabolic Syndrome and Osteoarthritis: Insights From Cross-Trait Analysis

CONTEXT

Previous observational studies have indicated a bidirectional association between metabolic syndrome (MetS) and osteoarthritis (OA). However, it remains unclear whether these bidirectional associations reflect causal relationships or shared genetic factors, and the underlying biological mechanisms of this association are not fully understood.

OBJECTIVE

We aimed to explore the genetic connection between MetS and OA using genome-wide association study (GWAS) summary data.

METHODS

Leveraging summary statistics from GWAS conducted by the UK Biobank and the Glucose and Insulin-related Traits Consortium (MAGIC), we performed global genetic correlation analyses, genome-wide cross-trait meta-analyses, and a bidirectional two-sample Mendelian randomization analyses using summary statistics from GWAS to comprehensively assess the relationship of MetS and OA.

RESULTS

We first detected an extensive genetic correlation between MetS and OA (rg = 0.393, P = 1.52 × 10-18), which was consistent in 4 MetS components, including waist circumference, triglycerides, hypertension, and high-density lipoprotein cholesterol and OA with rg ranging from -0.229 to 0.490. We then discovered 32 variants jointly associated with MetS and OA through Multi-Trait Analysis of GWAS (MTAG). Co-localization analysis found 12 genes shared between MetS and OA, with functional implications in several biological pathways. Finally, Mendelian randomization analysis suggested genetic liability to MetS significantly increased the risk of OA, but no reverse causality was found.

CONCLUSION

Our results illustrate a common genetic architecture, pleiotropic loci, as well as causality between MetS and OA, potentially enhancing our knowledge of high comorbidity and genetic processes that overlap between the 2 disorders.

Association between Healthy Eating Index-2015 total and metabolic associated fatty liver disease in Americans: a cross-sectional study with U.S. National Health and Nutrition Examination Survey

Background

Utilizing the National Health and Nutrition Examination Survey (NHANES) dataset to investigate the relationship between dietary quality, as assessed by the Healthy Eating Index-2015 (HEI-2015), and the prevalence of metabolic associated fatty liver disease (MAFLD) among adults in the United States, our analysis revealed that an increased dietary quality was significantly correlated with a reduced risk of MAFLD in the American population.

Method

The NHANES dataset, encompassing the years 2017-2018 and comprising 3,557 participants, was incorporated into our analytical framework. Weighted multivariate linear regression model was performed to assess the linear relationship between the HEI-2015 and MAFLD. Dietary intake data were derived from two 24-h dietary recall interviews conducted as part of NHANES.

Results

Following multivariable adjustment, the weighted multivariable linear regression models demonstrated a negative correlation between the HEI-2015 total scores and the risk of MAFLD. The weighted logistic regression models revealed that each unit of increased HEI-2015 total value was associated with a 1.2% (95% CI: 0.9%, 1.5%; P < 0.001) decrease in the risk of f MAFLD. Upon categorization of the HEI-2015 scores into quartiles, the odds ratios (ORs) for the association between the risk of MAFLD and the quartile scores of HEI-2015, in comparison to the baseline quartile, were 0.945 (95% CI: 0.852-1.047; P = 0.279), 0.834 (95% CI: 0.750-0.927; P < 0.001), and 0.723 (95% CI: 0.646-0.811; P < 0.001), respectively. When participants were stratified by age and sex, subgroup analyses showed a similar trend. This pattern was also evident in the smooth curve fitting (SCF) and weighted generalized additive model (GAM).

Conclusion

Elevated dietary quality, as assessed by the total and component food scores of the HEI-2015, was significantly correlated with a diminished risk of MAFLD among participants in the NHANES survey featured in this investigation.

Mediators of the association between nut consumption and cardiovascular diseases: a two-step mendelian randomization study

Previous observational studies have reported inconsistent associations between nut consumption and cardiovascular diseases (CVD). This study aims to identify the causal relationship between different types of nuts consumption and CVD, and to quantify the potential mediating effects of cardiometabolic factors. We utilized Genome-Wide Association Study (GWAS) data to assess the causal effects of nut consumption on CVD using two-sample Mendelian randomization (MR) and a two-step MR analysis. The inverse variance weighted (IVW) method indicated that processed (salted or roasted) peanuts were potentially and positively associated with ischaemic heart disease (IHD) (OR 1.4866; 95%CI 1.0491-2.1065). No causal relationships were found between nuts consumption and other CVD outcomes, including atrial fibrillation, angina, coronary atherosclerosis, coronary heart disease, IHD, myocardial infarction, subarachnoid hemorrhage, intracerebral haemorrhage and stroke. Both MR-Egger and median-based methods yielded similar results to IVW. Furthermore, in the two-step MR analysis, fasting insulin, low-density lipoprotein cholesterol and fasting blood glucose were identified as mediators in the potential causal relationship between processed peanuts and IHD, explaining 16.98%, 6.38% and 4.91% of the mediation, respectively. In total, these mediators accounted for 28.27% of the association between salted or roasted peanuts and IHD.

Systematic functional characterization of non-coding regulatory SNPs associated with central obesity

Central obesity is associated with higher risk of developing a wide range of diseases independent of overall obesity. Genome-wide association studies (GWASs) have identified more than 300 susceptibility loci associated with central obesity. However, the functional understanding of these loci is limited by the fact that most loci are in non-coding regions. To address this issue, our study first prioritized 2,034 single-nucleotide polymorphisms (SNPs) based on fine-mapping and epigenomic annotation analysis. Subsequently, we employed self-transcribing active regulatory region sequencing (STARR-seq) to systematically evaluate the enhancer activity of these prioritized SNPs. The resulting data analysis identified 141 SNPs with allelic enhancer activity. Further analysis of allelic transcription factor (TF) binding prioritized 20 key TFs mediating the central-obesity-relevant genetic regulatory network. Finally, as an example, we illustrate the molecular mechanisms of how rs8079062 acts as an allele-specific enhancer to regulate the expression of its targeted RNF157. We also evaluated the role of RNF157 in the adipogenic differentiation process. In conclusion, our results provide an important resource for understanding the genetic regulatory mechanisms underlying central obesity.

Adipose tissue eQTL meta-analysis highlights the contribution of allelic heterogeneity to gene expression regulation and cardiometabolic traits

Complete characterization of the genetic effects on gene expression is needed to elucidate tissue biology and the etiology of complex traits. In the present study, we analyzed 2,344 subcutaneous adipose tissue samples and identified 34,774 conditionally distinct expression quantitative trait locus (eQTL) signals at 18,476 genes. Over half of eQTL genes exhibited at least two eQTL signals. Compared with primary eQTL signals, nonprimary eQTL signals had lower effect sizes, lower minor allele frequencies and less promoter enrichment; they corresponded to genes with higher heritability and higher tolerance for loss of function. Colocalization of eQTLs with genome-wide association study (GWAS) signals for 28 cardiometabolic traits identified 1,835 genes. Inclusion of nonprimary eQTL signals increased discovery of colocalized GWAS-eQTL signals by 46%. Furthermore, 21 genes with ≥2 colocalized GWAS-eQTL signals showed a mediating gene dosage effect on the GWAS trait. Thus, expanded eQTL identification reveals more mechanisms underlying complex traits and improves understanding of the complexity of gene expression regulation.

Anatomy, Histology, and Embryonic Origin of Adipose Tissue: Insights to Understand Adipose Tissue Homofunctionality in Regeneration and Therapies

Preadipocytes are formed during the 14th and 16th weeks of gestation. White adipose tissue, in particular, is generated in specific areas and thereby assembles after birth, rapidly increasing following the propagation of adipoblasts, which are considered the preadipocyte cell precursors. The second trimester of gestation is a fundamental phase of adipogenesis, and in the third trimester, adipocytes, albeit small may be present within the main deposition areas. In the course of late gestation, adipose tissue develops in the foetus and promotes the synthesis of large amounts of uncoupling protein 1, in similar quantities relative to differentiated brown adipose tissue. In mammals, differentiation occurs in two functionally different types of adipose cells: white adipose cells resulting from lipid storage and brown adipose cells from increased metabolic energy consumption. During skeletogenesis, synovial joints develop through the condensation of mesenchymal cells, which forms an insertional layer of flattened cells that umlaut skeletal elements, by sharing the same origin in the development of synovium. Peri-articular fat pads possess structural similarity with body subcutaneous white adipose tissue; however, they exhibit a distinct metabolic function due to the micro-environmental cues in which they are embedded. Fat pads are an important component of the synovial joint and play a key role in the maintenance of joint homeostasis. They are also implicated in pathological states such as osteoarthritis.In this paper we explore the therapeutic potential of adipocyte tissue mesenchymal precursor-based stem cell therapy linking it back to the anatomic origin of adipose tissue.

Multivariable MR Can Mitigate Bias in Two-Sample MR Using Covariable-Adjusted Summary Associations

Genome-wide association studies (GWAS) are hypothesis-free studies that estimate the association between polymorphisms across the genome with a trait of interest. To increase power and to estimate the direct effects of these single-nucleotide polymorphisms (SNPs) on a trait GWAS are often conditioned on a covariate (such as body mass index or smoking status). This adjustment can introduce bias in the estimated effect of the SNP on the trait. Two-sample Mendelian randomisation (MR) studies use summary statistics from GWAS estimate the causal effect of a risk factor (or exposure) on an outcome. Covariate adjustment in GWAS can bias the effect estimates obtained from MR studies conducted using covariate adjusted GWAS data. Multivariable MR (MVMR) is an extension of MR that includes multiple traits as exposures. Here we propose the use of MVMR to correct the bias in MR studies from covariate adjustment. We show how MVMR can recover unbiased estimates of the direct effect of the exposure of interest by including the covariate used to adjust the GWAS within the analysis. We apply this method to estimate the effect of systolic blood pressure on type-2 diabetes and the effect of waist circumference on systolic blood pressure. Our analytical and simulation results show that MVMR provides unbiased effect estimates for the exposure when either the exposure or outcome of interest has been adjusted for a covariate. Our results also highlight the parameters that determine when MR will be biased by GWAS covariate adjustment. The results from the applied analysis mirror these results, with equivalent results seen in the MVMR with and without adjusted GWAS. When GWAS results have been adjusted for a covariate, biasing MR effect estimates, direct effect estimates of an exposure on an outcome can be obtained by including that covariate as an additional exposure in an MVMR estimation. However, the estimated effect of the covariate obtained from the MVMR estimation is biased.

The causal association between body composition and 25-hydroxyvitamin D levels: A bidirectional Mendelian randomization analysis

Observational studies and meta-analyses have indicated a notable correlation between obesity and vitamin D deficiency, yet the causal relationship between the 2 remains contentious. This study employed a bidirectional Mendelian randomization (MR) analysis to explore the interrelation between obesity-associated body metrics: specifically body mass index (BMI), waist-to-hip ratio (WHR), body fat percentage (BFP), whole-body fat percentage (WHF), and 25-hydroxyvitamin D (25(OH)D) levels. Instrumental variables for BMI, WHR, BFP, whole body fat mass (WFM), and 25(OH)D were carefully selected based on predefined thresholds. The association between these metrics and 25(OH)D levels was assessed using the TwoSampleMR package in R 4.2.3. Analysis methods included inverse variance weighted (IVW), MR Egger regression, weighted median, weighted mode, and simple mode. Sensitivity analyses were conducted employing the TwoSampleMR and MR-PRESSO software packages in R 4.2.3 to evaluate heterogeneity and multiplicity of findings. All 4 body components exhibited statistically significant causal associations with decreased 25(OH)D levels: BMI (IVW: odds ratio [OR] = 0.912, 95% confidence interval [CI]: 0.888-0.937, P < .001), WHR (IVW: OR = 0.927, 95% CI: 0.882-0.975, P = .003), BFP (IVW: OR = 0.883, 95% CI: 0.867-0.899, P < .001), and WFM (IVW: OR = 0.850, 95% CI: 0.829-0.872, P < .001). However, no statistically significant inverse causative association was observed between these body components and 25(OH)D levels. Sensitivity analyses revealed no substantial heterogeneity or pleiotropy, ensuring robustness of the findings. This study substantiates a significant causal link between 4 obesity-related body components and decreased 25(OH)D levels, excluding reverse causality.

Association between walking pace and heart failure: A Mendelian randomization analysis

BACKGROUND AND AIM

The relationship between walking pace and heart failure (HF) has been recognized, yet the directionality and underlying mediating risk factors remain unclear.

METHODS AND RESULTS

This study utilized bidirectional two-sample Mendelian randomization (MR) with genome-wide association studies (GWAS) summary statistics to assess the causal relationships between walking pace and HF. Additionally, we employed a two-step Multivariable Mendelian Randomization (MVMR) to explore potential mediating factors. We further validated our findings by conducting two-sample MR with another available GWAS summary data on heart failure. Results indicated that genetically predicted increases in walking pace were associated with a reduced risk of HF (odds ratio (OR), 0.589, 95% confidence interval (CI): 0.417-0.832). Among the considered mediators, the waist-to-hip ratio (WHR) accounts for the largest proportion of the effect (45.7%, 95% CI: 13.2%, 78.2%). This is followed by type 2 diabetes at 24.4% (95% CI: 6.7%, 42.0%) and triglycerides at 18.6% (95% CI: 4.5%, 32.7%). Furthermore, our findings reveal that genetically predicted HF risk (OR, 0.975, 95% CI: 0.960-0.991) is associated with a slower walking pace. Validated findings were consistent with the main results.

CONCLUSIONS

In conclusion, MR analysis demonstrates that a slow walking pace is a reliable indicator of an elevated risk of HF, and the causal relationship is bidirectional. Interventions focusing on waist-to-hip ratio, type 2 diabetes, and triglycerides may provide valuable strategies for HF prevention in individuals with a slow walking pace.

Genetics of female and male reproductive traits and their relationship with health, longevity and consequences for offspring

Substantial shifts in reproductive behaviors have recently taken place in many high-income countries including earlier age at menarche, advanced age at childbearing, rising childlessness and a lower number of children. As reproduction shifts to later ages, genetic factors may become increasingly important. Although monogenic genetic effects are known, the genetics underlying human reproductive traits are complex, with both causal effects and statistical bias often confounded by socioeconomic factors. Here, we review genome-wide association studies (GWASs) of 44 reproductive traits of both female and male individuals from 2007 to early 2024, examining reproductive behavior, reproductive lifespan and aging, infertility and hormonal concentration. Using the GWAS Catalog as a basis, from 159 relevant studies, we isolate 37 genes that harbor association signals for four or more reproductive traits, more than half of which are linked to rare Mendelian disorders, including ten genes linked to reproductive-related disorders: FSHB, MCM8, DNAH2, WNT4, ESR1, IGSF1, THRB, BRWD1, CYP19A1 and PTPRF. We also review the relationship of reproductive genetics to related health and behavioral traits, aging and longevity and the effect of parental age on offspring outcomes as well as reflecting on limitations, open questions and challenges in this fast-moving field.

Relationship between socioeconomic status and stroke: An observational and network Mendelian randomization study

BACKGROUND

The relationship between socioeconomic status (SES) and stroke remains controversial, and the underlying mediator is unclear. This study aimed to assess the causal relationship of SES with stroke and its subtypes and to identify potential modifiable risk factors responsible for this relationship.

METHODS

The study included 372,437 participants from the UK Biobank. Over an average period of 12.13 years, 6,457 individuals (2.7 %) were recorded as having experienced a stroke. Cox proportional hazards model was used to determine the relationship between SES (average annual household income before tax and age at the end of full-time education) and stroke, ischemic stroke, and hemorrhagic stroke. Two-sample Mendelian randomization (MR) was employed to assess the causal relationship between SES and stroke and its subtypes. Furthermore, network MR was utilized to evaluate the potential mediating role of modifiable risk factors for stroke in this causal relationship.

RESULTS

After adjusting for factors such as sociodemographic characteristics, health behaviors, health status, and past medical history, participants in the second highest income group showed the lowest risk of stroke, with a hazard ratio (HR) of 0.780 (95 % confidence interval [CI]: 0.702-0.866), and for ischemic stroke, the HR was 0.701 (95 % CI: 0.618-0.795). Those who completed full-time education at the latest age group(>18 years) had the lowest risk of stroke (HR: 0.906, 95 % CI: 0.830-0.988) and ischemic stroke (HR: 0.897, 95% CI: 0.811-0.992). MR analysis showed that higher income and education were both associated with a lower risk of stroke (income: inverse-variance-weighted odds ratio [ORIVW] =0.796, 95 % CI: 0.675-0.940, education: ORIVW = 0.631, 95 % CI: 0.557-0.716) and ischemic stroke (income: ORIVW = 0.813, 95 % CI: 0.684-0.966, education: ORIVW = 0.641, 95 % CI: 0.559-0.735). Additionally, hypertension had the highest mediating effect on this relationship. It accounted for 57.12 % of the effect of income on stroke, 51.24 % on ischemic stroke, and 27 % and 24 % for education.

CONCLUSION

Higher SES was associated with a lower risk of stroke and ischemic stroke, and hypertension had the highest mediating effect on this causal relationship. The results have significant public health implications, emphasizing the importance of early intervention to reduce the risk of stroke in low SES populations.

Relationship between pelvic floor muscle function and insulin resistance among non-diabetic females: a 3d ultrasound evaluation

BACKGROUND

To use the three-dimensional (3D) ultrasound for assessment of pelvic floor muscle function in non-diabetic females with insulin resistance (IR), and to evaluate its functional relationship with insulin levels.

METHODS

From October 2022 to November 2023, 216 non-diabetic females with insulin-resistant (IR group) and 118 normal females (control group) were sequentially recruited from our hospital for our study. The 3D ultrasound was used to assess the levator hiatus in resting state for all females regarding diameter lines, perimeters and areas; as well as the Valsalva manoeuvre (VM). The t-test and linear regression model were used to analyse the collected data.

RESULTS

The analysis indicates that there were significant differences in the resting state of the levator hiatus between the IR and the control groups (14.8 ± 5.8 cm2 and 11.6 ± 2.7 cm2, p < 0.05); and in the VM (18.2 ± 6.3 cm2 and 13.4 ± 3. 4 cm2, p < 0.05). In addition, the anterior-posterior (AP) diameters of the hiatus on VM were significantly increased in the IR group (40.0 ± 4.7 mm and 33.0 ± 4.4 mm, p < 0.05). With insulin levels as the dependent variable, multivariate regression analysis shows that insulin levels were significantly correlated with the levator hiatus area on VM (p < 0.05) and waist circumference (p < 0.05). The pelvic organ descent on VM in the IR group was significant (p < 0.05).

CONCLUSIONS

The areas of resting state levator hiatus and on VM were significantly larger in the IR than that in the control groups. In addition, the position of the pelvic organ on VM in the IR group was significantly descended. The insulin levels were correlated with the pelvic floor muscle function.

Causal effect of waist-to-hip ratio on non-alcoholic fatty liver disease: a mendelian randomization study

Objective

This study aimed to explore the potential causal association between waist-to-hip ratio (WHR) and the risk of non-alcoholic fatty liver disease (NAFLD) via the Mendelian randomization (MR) approach.

Methods

Genetic variation data pertaining to WHR served as instrumental variables, while genome-wide association study data for NAFLD constituted the outcome event. Primarily, the random-effects inverse-variance weighted (IVW) method was utilized, supplemented by MR Egger, weighted median, simple mode, and weighted mode analyses. Sensitivity analysis entailed the "leave-one-out" approach, with the IVW results forming the foundational basis for this study.

Results

This analysis included a total of 28 valid single nucleotide polymorphisms (SNPs). IVW analysis indicated an increased risk of NAFLD associated with WHR (OR = 1.61; 95% CI: 1.08-2.41; P = 0.02). Furthermore, MR-Egger regression analysis revealed the absence of horizontal pleiotropy among the included SNPs, albeit with some sample heterogeneity. Lastly, the "leave-one-out" sensitivity analysis demonstrated that no individual SNP significantly influenced the estimated causal association.

Conclusion

This study furnishes indicative evidence of a causal link between waist-to-hip ratio and the risk of NAFLD occurrence.

Association Between the Weight-Adjusted Waist Index and OSA Risk: Insights from the NHANES 2017-2020 and Mendelian Randomization Analyses

Background

Obesity is a significant risk factor for obstructive sleep apnea (OSA). The weight-adjusted-waist index (WWI) reflects weight-independent centripetal obesity. Our study aims to evaluate the relationship between WWI and OSA.

Methods

The data used in the current cross-sectional investigation are from the National Health and Nutrition Examination Survey (NHANES), which was carried out between 2017 and 2020. We utilized weighted multivariable-adjusted logistic regression to evaluate the relationship between WWI and the risk of OSA. In addition, we applied various analytical methods, including subgroup analysis, smoothing curve fitting, threshold effect analysis and the receiver operating characteristic (ROC) curve. To further explore the relationship, we conducted a MR study using genome-wide association study (GWAS) summary statistics. We performed the main inverse variance weighting (IVW) method along with other supplementary MR methods. In addition, a meta-analysis was conducted to provide an overall evaluation.

Results

WWI was positively related to OSA with the full adjustment [odds ratio (OR)=1.14, 95% confidence interval (95% CI): 1.06-1.23, P<0.001]. After converting WWI to a categorical variable by quartiles (Q1-Q4), compared to Q1 the highest WWI quartile was linked to an obviously increased likelihood of OSA (OR=1.26, 95% CI: 1.06-1.50. P=0.01). Subgroup analysis revealed the stability of the independent positive relationship between WWI and OSA. Smoothing curve fitting identified a saturation effect of WWI and OSA, with an inflection point of 11.62. In addition, WWI had the strongest prediction for OSA (AUC=0.745). Sensitivity analysis was performed to verify the significantly positive connection between WWI and stricter OSA (OR=1.18, 95% CI: 1.05-1.32, P=0.005). MR meta-analysis further supported our results (OR=2.11, 95% CI: 1.94-2.30, P<0.001). Sensitivity analysis confirmed the robustness and reliability of these findings.

Conclusion

WWI was significantly associated with the risk of OSA, suggesting that WWI could potentially serve as a predictor for OSA.

The association between metabolic syndrome and lung cancer risk: a Mendelian randomization study

Metabolic syndrome (MetS) is closely linked to cancer development, with emerging evidence suggesting its association with pulmonary carcinoma. However, causal relationships remain unclear due to observational study limitations. Employing Mendelian randomization, we investigated the causal link between MetS and lung cancer (LC) susceptibility. The data utilized in this study were obtained from the publicly available genetic variation summary database. The causal relationship was assessed using the inverse variance weighting method (IVW), weighted median method, and MR-Egger regression. A sensitivity analysis was carried out to confirm the robustness of the findings. Furthermore, risk factor analyses were conducted to explore potential mediators. Utilizing various analyses, MetS demonstrated a significant positive association with LC (OR, 1.22; 95% CI, 1.09-1.37, p = 7.57 × 10- 4), lung squamous cell carcinoma (LUSC) (OR, 1.47; 95%, 1.23-1.75, p = 2.22 × 10- 5), and small cell lung cancer (SCLC) (OR, 1.76; 95% CI, 1.37-2.26, p = 8.20 × 10- 6) but not lung adenocarcinoma (LUAD) (OR, 1.08; 95% CI, 0.94-1.24, p = 0.28). Risk factor analyses indicated that smoking, alcohol, body mass index, education, and type 2 diabetes might mediate the association. This study genetically validates and reinforces the evidence of MetS increasing the incidence of LC, including both LUSC) and SCLC, especially among individuals with abdominal obesity. It provides valuable insights for the development of lung cancer prevention strategies and directions for future research.

The extracellular vesicle transcriptome provides tissue-specific functional genomic annotation relevant to disease susceptibility in obesity

We characterized circulating extracellular vesicles (EVs) in obese and lean humans, identifying transcriptional cargo differentially expressed in obesity. Since circulating EVs may have broad origin, we compared this obesity EV transcriptome to expression from human visceral adipose tissue derived EVs from freshly collected and cultured biopsies from the same obese individuals. Using a comprehensive set of adipose-specific epigenomic and chromatin conformation assays, we found that the differentially expressed transcripts from the EVs were those regulated in adipose by BMI-associated SNPs from a large-scale GWAS. Using a phenome-wide association study of the regulatory SNPs for the EV-derived transcripts, we identified a substantial enrichment for inflammatory phenotypes, including type 2 diabetes. Collectively, these findings represent the convergence of the GWAS (genetics), epigenomics (transcript regulation), and EV (liquid biopsy) fields, enabling powerful future genomic studies of complex diseases.

Gene-environment interactions in the influence of maternal education on adolescent neurodevelopment using ABCD study

Maternal education was strongly correlated with adolescent brain morphology, cognitive performances, and mental health. However, the molecular basis for the effects of maternal education on the structural neurodevelopment remains unknown. Here, we conducted gene-environment-wide interaction study using the Adolescent Brain Cognitive Development cohort. Seven genomic loci with significant gene-environment interactions (G×E) on regional gray matter volumes were identified, with enriched biological functions related to metabolic process, inflammatory process, and synaptic plasticity. Additionally, genetic overlapping results with behavioral and disease-related phenotypes indicated shared biological mechanism between maternal education modified neurodevelopment and related behavioral traits. Finally, by decomposing the multidimensional components of maternal education, we found that socioeconomic status, rather than family environment, played a more important role in modifying the genetic effects on neurodevelopment. In summary, our study provided analytical evidence for G×E effects regarding adolescent neurodevelopment and explored potential biological mechanisms as well as social mechanisms through which maternal education could modify the genetic effects on regional brain development.

Increased NOX-dependent ROS production and proportionally enhanced antioxidant response in white adipose tissue of male rats

Objective

This study aimed to investigate the redox balance in subcutaneous and retroperitoneal fat pads of male and female Wistar rats.

Materials and methods

The study analyzed the activity and gene expression of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, along with the production of NADPH oxidases dependent on H2O2 and gene expression of NOX1, NOX2, and NOX4.

Results

The retroperitoneal fat pad in males compared with females had greater NOX2 and NOX4 expression, along with higher superoxide dismutase activity. Additionally, their subcutaneous fat pad had greater NOX4 expression and higher intracellular H2O2 production, together with greater expression and activity of both superoxide dismutase and catalase.

Conclusion

The white adipose tissue of male rats had greater reactive oxygen species (ROS) production compared with that of female rats, but also a proportionally greater antioxidant response. These findings are important for ongoing investigations into how sex differences may be linked to the development of metabolic diseases and the unique susceptibilities of each sex.

Waist-to-hip ratio and nonalcoholic fatty liver disease: a clinical observational and Mendelian randomization analysis

Background

Obesity often coincides with non-alcoholic fatty liver disease (NAFLD), yet a significant portion of NAFLD patients exhibit normal body mass index (BMI) but have abdominal obesity. Recognizing this discrepancy, we aimed to delve deeper into this phenomenon through observational studies coupled with two-sample Mendelian randomization (MR) analysis, with waist-to-hip ratio (WHR) serving as the indicator for abdominal obesity. Our objective was to ascertain whether WHR correlates with an increased risk of NAFLD development.

Methods

This study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 to examine the association between WHR and NAFLD through weighted multivariate logistic regression models. On this basis, subgroup analyses were performed to further explore the correlation between WHR and NAFLD. Subsequently, a two-sample MR analysis was conducted using genome-wide association studies (GWAS) data to investigate the potential causal relationship between WHR and NAFLD. Sensitivity analyses were also employed to ensure the robustness of our findings.

Results

A total of 3,732 eligible participants were included in the analysis. Weighted multivariable-adjusted logistic regression models revealed a positive association between WHR and the risk of NAFLD (Q2vsQ1: OR = 1.94 [95% CI: 1.55-2.44]; Q3vsQ1: OR = 2.08 [95% CI: 1.51-2.85]; Q4vsQ1: OR = 3.70 [95% CI: 2.13-6.43], p < 0.05). The results of the subgroup analysis suggested that there was an interaction in the correlation between WHR and NAFLD in normal weight, overweight, and obese populations (p < 0.05). The RCS curves indicated that there was a nonlinear relationship between WHR and NAFLD in populations with BMI in the normal versus obese categories. Furthermore, MR analysis provided additional support for the causal relationship between WHR and NAFLD. Using inverse variance weighting (IVW), the MR analysis yielded an OR of 2.062 (95% CI: 1.680-2.531, p<0.05). Consistent results were obtained with the other four MR methods, all supporting the same direction of causality. Sensitivity analyses were performed to assess the robustness of the findings (p > 0.5), further reinforcing the reliability of the observed associations.

Conclusion

WHR elevation heightens the susceptibility to NAFLD.

In silico and functional analysis identifies key gene networks and novel gene candidates in obesity-linked human visceral fat

OBJECTIVE

Visceral adiposity is associated with increased proinflammatory activity, insulin resistance, diabetes risk, and mortality rate. Numerous individual genes have been associated with obesity, but studies investigating gene regulatory networks in human visceral obesity have been lacking.

METHODS

We analyzed gene regulatory networks in human visceral adipose tissue (VAT) from 48 and 11 Chinese patients with and without obesity, respectively, using gene coexpression and gene regulatory network construction from RNA-sequencing data. We also conducted RNA interference-based functional tests on selected genes for effects on adipocyte differentiation.

RESULTS

A scale-free gene coexpression network was constructed from 360 differentially expressed genes between VAT samples from patients with and without obesity (absolute log fold change > 1, false discovery rate [FDR] < 0.05), with edge probability > 0.8. Gene regulatory network analysis identified candidate transcription factors associated with differentially expressed genes. A total of 15 subnetworks (communities) displayed altered connectivity patterns between obesity and nonobesity networks. Genes in proinflammatory pathways showed increased network connectivity in VAT samples with obesity, whereas the oxidative phosphorylation pathway displayed reduced connectivity (enrichment FDR < 0.05). Functional screening via RNA interference identified genes such as SOX30, SIRPB1, and OSBPL3 as potential network-derived candidates influencing adipocyte differentiation.

CONCLUSIONS

This approach highlights the network architecture in human obesity, identifies novel candidate genes, and generates new hypotheses regarding network-assisted gene regulation in VAT.

LCoRL Regulates Growth and Metabolism

Genome-wide association studies (GWAS) in humans and livestock have identified genes associated with metabolic traits. However, the causality of many of these genes on metabolic homeostasis is largely unclear due to a lack of detailed functional analyses. Here we report ligand-dependent corepressor-like (LCoRL) as a metabolic regulator for body weight and glucose homeostasis. Although GWAS data show that LCoRL is strongly associated with body size, glucose homeostasis, and other metabolic traits in humans and livestock, functional investigations had not been performed. We generated Lcorl knockout mice (Lcorl-/-) and characterized the metabolic traits. We found that Lcorl-/- pups are born smaller than the wild-type (WT) littermates before reaching normal weight by 7 to 9 weeks of age. While aging, Lcorl-/- mice remain lean compared to WT mice, which is associated with a decrease in daily food intake. Glucose tolerance and insulin sensitivity are improved in Lcorl-/- mice. Mechanistically, this stunted growth is linked to a reduction of circulating levels of IGF-1. The expression of the genes downstream of GH signaling and the genes involved in glucose and lipid metabolism are altered in the liver of Lcorl-/- mice. Furthermore, Lcorl-/- mice are protected against a high-fat diet challenge and show reduced exercise capacity in an exercise stress test. Collectively, our results are congruent with many of the metabolic parameters linked to the Lcorl locus as reported in GWAS in humans and livestock.

A methodology for gene level omics-WAS integration identifies genes influencing traits associated with cardiovascular risks: the Long Life Family Study

The Long Life Family Study (LLFS) enrolled 4953 participants in 539 pedigrees displaying exceptional longevity. To identify genetic mechanisms that affect cardiovascular risks in the LLFS population, we developed a multi-omics integration pipeline and applied it to 11 traits associated with cardiovascular risks. Using our pipeline, we aggregated gene-level statistics from rare-variant analysis, GWAS, and gene expression-trait association by Correlated Meta-Analysis (CMA). Across all traits, CMA identified 64 significant genes after Bonferroni correction (p ≤ 2.8 × 10-7), 29 of which replicated in the Framingham Heart Study (FHS) cohort. Notably, 20 of the 29 replicated genes do not have a previously known trait-associated variant in the GWAS Catalog within 50 kb. Thirteen modules in Protein-Protein Interaction (PPI) networks are significantly enriched in genes with low meta-analysis p-values for at least one trait, three of which are replicated in the FHS cohort. The functional annotation of genes in these modules showed a significant over-representation of trait-related biological processes including sterol transport, protein-lipid complex remodeling, and immune response regulation. Among major findings, our results suggest a role of triglyceride-associated and mast-cell functional genes FCER1A, MS4A2, GATA2, HDC, and HRH4 in atherosclerosis risks. Our findings also suggest that lower expression of ATG2A, a gene we found to be associated with BMI, may be both a cause and consequence of obesity. Finally, our results suggest that ENPP3 may play an intermediary role in triglyceride-induced inflammation. Our pipeline is freely available and implemented in the Nextflow workflow language, making it easily runnable on any compute platform ( https://nf-co.re/omicsgenetraitassociation ).

How Real-World Data Can Facilitate the Development of Precision Medicine Treatment in Psychiatry

Precision medicine has the ambition to improve treatment response and clinical outcomes through patient stratification and holds great potential for the treatment of mental disorders. However, several important factors are needed to transform current practice into a precision psychiatry framework. Most important are 1) the generation of accessible large real-world training and test data including genomic data integrated from multiple sources, 2) the development and validation of advanced analytical tools for stratification and prediction, and 3) the development of clinically useful management platforms for patient monitoring that can be integrated into health care systems in real-life settings. This narrative review summarizes strategies for obtaining the key elements-well-powered samples from large biobanks integrated with electronic health records and health registry data using novel artificial intelligence algorithms-to predict outcomes in severe mental disorders and translate these models into clinical management and treatment approaches. Key elements are massive mental health data and novel artificial intelligence algorithms. For the clinical translation of these strategies, we discuss a precision medicine platform for improved management of mental disorders. We use cases to illustrate how precision medicine interventions could be brought into psychiatry to improve the clinical outcomes of mental disorders.

Aging reveals a sex-dependent susceptibility of sarcospan-deficient mice to cardiometabolic disease

Numerous genes including sarcospan (SSPN) have been designated as obesity-susceptibility genes by human genome-wide association studies. Variants in the SSPN locus have been linked with sex-dependent obesity-associated traits; however, this association has not been investigated in vivo. To delineate the role SSPN plays in regulating metabolism with potential to impact cardiac function, we subjected young and aged global SSPN-deficient (SSPN-/-) male and female mice to obesogenic conditions (60% fat diet). We hypothesized that loss of SSPN combined with metabolic stress would increase susceptibility of mice to cardiometabolic disease. Baseline and end-point assessments of several anthropometric parameters were performed including weight, glucose tolerance, and fat distribution of mice fed control (CD) and high-fat (HFD) diet. Doppler echocardiography was used to monitor cardiac function. White adipose and cardiac tissues were assessed for inflammation by histological, gene expression, and cytokine analysis. Overall, SSPN deficiency protected both sexes and ages from diet-induced obesity, with a greater effect in females. SSPN-/- HFD mice gained less weight than wild-type (WT) cohorts, while SSPN-/- CD groups increased weight. Furthermore, aged SSPN-/- mice developed glucose intolerance regardless of diet. Echocardiography showed preserved systolic function for all groups; however, aged SSPN-/- males exhibited significant increases in left ventricular mass (CD) and signs of diastolic dysfunction (HFD). Cytokine analysis revealed significantly increased IL-1α and IL-17Α in white adipose tissue from young SSPN-/- male mice, which may be protective from diet-induced obesity. Overall, these studies suggest that several sex-dependent mechanisms influence the role SSPN plays in metabolic responses that become evident with age.NEW & NOTEWORTHY Young and aged sarcospan (SSPN)-deficient mice were examined to assess the role of SSPN in obesity and cardiometabolic disease. Both sexes displayed a "leaner" phenotype in response to high-fat diet (HFD). Notably, several sex differences were identified in aged SSPN-deficient mice: 1) females developed glucose intolerance (control and HFD) and 2) males exhibited increased left ventricular mass (control) and diastolic dysfunction (HFD). Therefore, we conclude that SSPN exerts a sex-dependent influence on obesity-associated diseases.

A Mendelian randomization study on causal relationship between metabolic factors and abnormal spermatozoa

Background

Male infertility is a global health problem. There is an increasing attention on the association of metabolic status with spermatogenesis. However, the impacts of metabolic factors on semen parameters are still unclear. To provide evidence for developing appropriate interventions on disease screening and prevention, we performed a Mendelian randomization (MR) analysis to assess causality between various metabolic factors and abnormal spermatozoa.

Methods

We conducted a two-sample MR study to appraise the causal effects of 16 metabolic factors (including indexes of metabolic traits, glucose metabolism, lipid profile, adipokines, uric acid and metabolic diseases) on abnormal spermatozoa from genome-wide association studies (GWASs). Filtering with strict criteria, eligible genetic instruments closely associated with each of the factors were extracted. We employed inverse variance weighted for major analysis, with supplement MR methods including MR-Egger and weighted median. Heterogeneity and pleiotropy tests were further used to detect the reliability of analysis.

Results

After rigorous quality control in this MR framework, we identified that body fat percentage [odds ratio (OR) =1.49, 95% confidence interval (CI): 1.01-2.20, P=0.046] and resistin (OR =1.55, 95% CI: 1.11-2.19, P=0.01) were causally associated with a higher risk of abnormal spermatozoa. In terms of other indexes of metabolic traits, glucose metabolism, serum lipid profile and uric acid and metabolic diseases including type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD), no causal effects were observed (P>0.05).

Conclusions

Our MR analysis provides robust evidence that body fat percentage and resistin are risk factors for abnormal spermatozoa, suggesting implications of identifying them for potential interventions and clinical therapies in male infertility. Further investigation in larger-scale GWASs on subgroups of abnormal spermatozoa will verify impacts of metabolic factors on spermatogenesis.

A growth curve model to estimate longitudinal effects of parental BMI on Indonesian children's growth patterns

The global surge in childhood obesity is also evident in Indonesia. Parental body mass index (BMI) values were found to be one of the major determinants of the increasing prevalence of childhood obesity. It is uncertain if parental BMI during their offspring's childhood significantly affects their children's BMI trajectories into adulthood. We aimed to investigate the influence of parental BMI Z-scores on BMI trajectories of Indonesian school-aged children, with a focus on sex-specific effects. This study utilized data from the Indonesian Family Life Survey and tracked the same respondents over four time points, from wave 2 (1997-1998) to wave 5 (2014-2015). The sample of this study consisted of children aged 5-12 years in wave 2 for whom height and weight data were available. We utilized a two-level growth curve model to account for the hierarchical structure of the data, with time nested within individual children. Fathers' BMI Z-scores in wave 2 had a pronounced influence (β = 0.31) on female children's BMI Z-scores compared to the influence of mothers' BMI Z-scores (β = 0.17). Mothers' BMI Z-scores in wave 2 showed a stronger positive association with male children's BMI Z-scores (β = 0.22) than did the father's BMI Z-scores (β = 0.19). A significant interaction of fathers' BMI Z-scores and years of follow-up was found for male children. As male children's BMI Z-scores increased by year, this effect was stronger in those whose fathers' BMI Z-scores were at a higher level. In conclusion, we found that parental BMI values profoundly influenced their children's BMI trajectories.

Understanding the Genetic Landscape of Gestational Diabetes: Insights into the Causes and Consequences of Elevated Glucose Levels in Pregnancy

Background/Objectives: During pregnancy, physiological changes in maternal circulating glucose levels and its metabolism are essential to meet maternal and fetal energy demands. Major changes in glucose metabolism occur throughout pregnancy and consist of higher insulin resistance and a compensatory increase in insulin secretion to maintain glucose homeostasis. For some women, this change is insufficient to maintain normoglycemia, leading to gestational diabetes mellitus (GDM), a condition characterized by maternal glucose intolerance and hyperglycaemia first diagnosed during the second or third trimester of pregnancy. GDM is diagnosed in approximately 14.0% of pregnancies globally, and it is often associated with short- and long-term adverse health outcomes in both mothers and offspring. Although recent studies have highlighted the role of genetic determinants in the development of GDM, research in this area is still lacking, hindering the development of prevention and treatment strategies. Methods: In this paper, we review recent advances in the understanding of genetic determinants of GDM and glycaemic traits during pregnancy. Results/Conclusions: Our review highlights the need for further collaborative efforts as well as larger and more diverse genotyped pregnancy cohorts to deepen our understanding of the genetic aetiology of GDM, address research gaps, and further improve diagnostic and treatment strategies.

The Mediating Roles of Lung Function Traits and Inflammatory Factors on the Associations between Measures of Obesity and Risk of Lower Respiratory Tract Infections: A Mendelian Randomization Study

BACKGROUND

Identifying mediators between obesity-related traits and lower respiratory tract infections (LRTIs) would inform preventive and therapeutic strategies to reduce the burden of LRITs. We aimed to recognize whether lung function and inflammatory factors mediate their associations.

METHODS

We conducted a two-step, two-sample Mendelian randomization (MR) analysis. Two-sample MR was performed on (1) obesity-related traits (i.e., body mass index [BMI], waist circumference [WC], and waist-to-hip ratio [WHR]) and LRTIs (i.e., acute bronchitis, acute bronchiolitis, bronchiectasis, influenza, and pneumonia), (2) obesity-related traits and potential mediators, and (3) potential mediators and LRTIs. Next, two-step MR was applied to infer whether the mediation effects exist.

RESULTS

We found that C-reactive protein (CRP), interleukin-6 (IL-6), and forced expiratory volume in the first second (FEV1) mediated 32.59% (95% CI: 17.90%, 47.27%), 7.96% (95% CI: 1.79%, 14.14%), and 4.04% (95% CI: 0.34%, 7.74%) of the effect of BMI on pneumonia, and they mediated 26.90% (95% CI: 13.98%, 39.83%), 10.23% (95% CI: 2.72%, 17.73%), and 4.67% (95% CI: 0.25%, 9.09%) of the effect of WC on pneumonia, respectively. Additionally, CRP, forced vital capacity (FVC), and FEV1 mediated 18.66% (95% CI: 8.70%, 28.62%), 8.72% (95% CI: 1.86%, 15.58%), and 8.41% (95% CI: 2.77%, 14.06%) of the effect of BMI on acute bronchitis, and they mediated 19.96% (95% CI: 7.44%, 32.48%), 12.19% (95% CI: 2.00%, 22.39%), and 12.61% (95% CI: 2.94%, 22.29%) of the effect of WC on acute bronchitis, respectively.

CONCLUSIONS

Health interventions linked to reducing inflammation and maintaining normal lung function could help mitigate the risk of obesity-related LRTIs.

Genetically predicted frailty index and risk of chronic kidney disease

Previous findings have reported the association between frailty and chronic kidney disease. However, the causality remains ambiguous. This study aimed to determine whether frailty index is causally associated with chronic kidney disease. We obtained the frailty genome-wide association study (GWAS) data and chronic kidney disease GWAS data from the FinnGen R5 (total n = 216,743; case = 3902, control = 212,841) as the exposure and outcome, respectively. A two-sample Mendelian randomization (MR) analysis was primarily conducted using the inverse-variance weighted (IVW), weighted median and MR-Egger regression analyses. Multivariable MR analysis (MVMR) was conducted for additional adjustment. In the two-sample Mendelian randomization analyses, a total of 14 single nucleotide polymorphisms (SNPs) were recognized as effective instrumental variables. The IVW method showed evidence to support a causal association between frailty index and chronic kidney disease (beta = 1.270; 95% CI 0.608 to 1.931; P < 0.001). MR-Egger revealed a causal association between frailty index and chronic kidney disease (beta = 3.612; 95% CI 0.805 to 6.419; P = 0.027). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept =  - 0.053; P = 0.119). The weighted median approach and weighted mode method also demonstrated a causal association between frailty index and chronic kidney disease (beta = 1.148; 95% CI 0.278 to 2.019; P = 0.011; beta = 2.194; 95% CI 0.598 to 3.790; P = 0.018). Cochran's Q test and the funnel plot indicated no directional pleiotropy. MVMR analysis revealed that the causal association between frailty index and chronic kidney disease remained after adjusting for potential confounders, body-mass index, inflammatory bowel disease, waist-hip ratio, and C-reactive protein. Our study provides evidence of causal association between frailty and chronic kidney disease from genetic perspectives.

Genetic estimation of causalities between educational attainment with common digestive tract diseases and the mediating pathways

BACKGROUND

The association between education, intelligence, and cognition with digestive tract diseases has been established. However, the specific contribution of each factor in the pathogenesis of these diseases are still uncertain.

METHOD

This study employed multivariable Mendelian randomization (MR) to assess the independent effects of education, intelligence, and cognition on gastrointestinal conditions in the FinnGen and UK Biobank European-ancestry populations. A two-step MR approach was employed to assess the mediating effects of the association.

RESULTS

Meta-analysis of MR estimates from FinnGen and UK Biobank showed that 1- SD (4.2 years) higher education was causally associated with lower risks of gastroesophageal reflux (OR: 0.58; 95% CI: 0.50, 0.66), peptic ulcer (OR: 0.57; 95% CI: 0.47, 0.69), irritable bowel syndrome (OR: 0.70; 95% CI: 0.56, 0.87), diverticular disease (OR: 0.69; 95% CI: 0.61, 0.78), cholelithiasis (OR: 0.68; 95% CI: 0.59, 0.79) and acute pancreatitis (OR: 0.54; 95% CI: 0.41, 0.72), independently of intelligence and cognition. These causal associations were mediating by body mass index (3.7-22.3%), waist-to-hip ratio (8.3-11.9%), body fat percentage (4.1-39.8%), fasting insulin (1.4-5.5%) and major depression (6.0-12.4%).

CONCLUSION

Our findings demonstrate a causal and independent association between education and six common digestive tract diseases. Additionally, our study highlights five mediators as crucial targets for preventing digestive tract diseases associated with lower education levels.

Genetic causality between modifiable risk factors and the risk of rheumatoid arthritis: Evidence from Mendelian randomization

OBJECTIVES

Emerging research has investigated the potential impact of several modifiable risk factors on the risks of rheumatoid arthritis (RA), but the findings did not yield consistent results. This study aimed to comprehensively explore the genetic causality between modifiable risk factors and the susceptibility of RA risk using the Mendelian randomization (MR) approach.

METHODS

Genetic instruments for modifiable risk factors were selected from several genome-wide association studies at the genome-wide significance level (p < 5 × 10-8), respectively. Summary-level data for RA were sourced from a comprehensive meta-analysis. The causal estimates linking modifiable risk factors to RA risk were assessed using MR analysis with inverse variance weighting (IVW), MR-Egger, weighted, and weighted median methods.

RESULTS

After Bonferroni correction for multiple tests, we found the presence of causality between educational attainment and RA, where there were protective effects of educational attainment (college completion) (odds ratio [OR] = 0.50, 95% CI = 0.36, 0.69, p = 2.87E-05) and educational attainment (years of education) (OR = 0.93, 95% CI = 0.90, 0.96, p = 4.18E-06) on the lower RA risks. Nevertheless, smoking initiation was observed to be associated with increased RA risks (OR = 1.27, 95% CI = 1.09, 1.47, p = .002). Moreover, there was no indication of horizontal pleiotropy of genetic variants during causal inference between modifiable risk factors and RA.

CONCLUSIONS

Our study reveals the genetic causal impacts of educational attainment and smoking on RA risks, suggesting that the early monitoring and recognition of modifiable risk factors would be beneficial for the preventive counseling/treatment strategies for RA.

Identification of novel genes whose expression in adipose tissue affects body fat mass and distribution: an RNA-Seq and Mendelian Randomization study

Many studies have shown that abdominal adiposity is more strongly related to health risks than peripheral adiposity. However, the underlying pathways are still poorly understood. In this cross-sectional study using data from RNA-sequencing experiments and whole-body MRI scans of 200 participants in the EPIC-Potsdam cohort, our aim was to identify novel genes whose gene expression in subcutaneous adipose tissue has an effect on body fat mass (BFM) and body fat distribution (BFD). The analysis identified 625 genes associated with adiposity, of which 531 encode a known protein and 487 are novel candidate genes for obesity. Enrichment analyses indicated that BFM-associated genes were characterized by their higher than expected involvement in cellular, regulatory and immune system processes, and BFD-associated genes by their involvement in cellular, metabolic, and regulatory processes. Mendelian Randomization analyses suggested that the gene expression of 69 genes was causally related to BFM and BFD. Six genes were replicated in UK Biobank. In this study, we identified novel genes for BFM and BFD that are BFM- and BFD-specific, involved in different molecular processes, and whose up-/downregulated gene expression may causally contribute to obesity.

Genetic associations of birthweight, childhood, and adult BMI with metabolic dysfunction-associated steatotic liver disease: a Mendelian randomization

PURPOSE

The causal relationship between life course adiposity with metabolic dysfunction-associated steatotic liver disease (MASLD) is ambiguous. We aimed to investigate whether there is an independent genetic causal relationship between body size at various life course and MASLD.

METHODS

We performed univariable and multivariable Mendelian randomization (MR) to estimate the causal effect of body size at different life stages on MASLD (i.e., defined by the clinical comprehensive diagnosis from the electronic health record [HER] codes [ICD9/ICD10] or diagnostic phrases), including birthweight, childhood body mass index (BMI), adult BMI, waist circumference (WC), waist-to-hip ratio (WHR), body fat percentage (BFP).

RESULTS

In univariate analyses, higher genetically predicted lower birthweight (ORIVW = 0.61, 95%CI, 0.52 to 0.74), Childhood BMI ( ORIVW = 1.37, 95%CI, 1.12 to 1.64), and adult BMI (ORIVW = 1.41, 95%CI, 1.27 to 1.57) was significantly associated with subsequent risk of MASLD after Bonferroni correction. The MVMR analysis demonstrated compelling proof that birthweight and adult BMI had a direct causal relationship with MASLD. However, after adjusting for birthweight and adult BMI, the direct causal relationship between childhood BMI and MASLD disappeared.

CONCLUSION

For the first time, this MR elucidated new evidence for the effect of life course adiposity on MASLD risk, providing lower birthweight and duration of obesity are independent risk factors for MASLD. Our findings indicated that weight management during distinct time periods plays a significant role in the prevention and treatment of MASLD.

p53 target ANKRA2 cooperates with RFX7 to regulate tumor suppressor genes

The transcription factor regulatory factor X 7 (RFX7) has been identified as a tumor suppressor that is recurrently mutated in lymphoid cancers and appears to be dysregulated in many other cancers. RFX7 is activated by the well-known tumor suppressor p53 and regulates several other known tumor suppressor genes. However, what other factors regulate RFX7 and its target genes remains unclear. Here, reporter gene assays were used to identify that RFX7 regulates the tumor suppressor gene PDCD4 through direct interaction with its X-box promoter motif. We utilized mass spectrometry to identify factors that bind to DNA together with RFX7. In addition to RFX7, we also identified RFX5, RFXAP, RFXANK, and ANKRA2 that bind to the X-box motif in the PDCD4 promoter. We demonstrate that ANKRA2 is a bona fide direct p53 target gene. We used transcriptome analyses in two cell systems to identify genes regulated by ANKRA2, its sibling RFXANK, and RFX7. These results revealed that ANKRA2 functions as a critical cofactor of RFX7, whereas RFXANK regulates largely distinct gene sets.

Genetically Predicted Association of 91 Circulating Inflammatory Proteins with Multiple Sclerosis: A Mendelian Randomization Study

Previous studies have validated a close association between inflammatory factors and multiple sclerosis (MS), but their causal relationship is not fully profiled yet. This study used Mendelian randomization (MR) to investigate the causal effect of circulating inflammatory proteins on MS. Data from a large-scale genome-wide association study (GWAS) were analyzed using a two-sample MR method to explore the relationship between 91 circulating inflammatory proteins and MS. The inverse-variance-weighted (IVW) analysis was employed as the main method for evaluating exposures and outcomes. Furthermore, series of the methods of MR Egger, weighted median, simple mode, and weighted mode were used to fortify the final results. The results of the IVW method were corrected with Bonferroni (bon) and false discovery rate (fdr) for validating the robustness of results and ensuring the absence of heterogeneity and horizontal pleiotropy. The sensitivity analysis was also performed. The results of the forward MR analysis showed that higher levels of CCL25 were found to be associated with an increased risk of MS according to IVW results, OR: 1.085, 95% CI (1.011, 1.165), p = 2.42 × 10-2, adjusted p_adj_bon = 1, p_adj_fdr = 0.307. Similarly, higher levels of CXCL10 were found to be associated with an increased risk of MS, OR: 1.231, 95% CI (1.057, 1.433), p = 7.49 × 10-3, adjusted p_adj_bon = 0.682, p_adj_fdr = 0.227. In contrast, elevated levels of neurturin (NRTN) were associated with a decreased risk of MS, OR: 0.815, 95% CI (0.689, 0.964), p = 1.68 × 10-2, adjusted p_adj_bon = 1, p_adj_fdr = 0.307. Reverse MR analysis showed no causal relationship between MS and the identified circulating inflammatory cytokines. The effects of heterogeneity and level pleiotropy were further excluded by sensitivity analysis. This study provides new insights into the relationship between circulating inflammatory proteins and MS and brings up a new possibility of using these cytokines as potential biomarkers and therapeutic targets. The data in this study show that there are only weak associations between inflammatory molecules and MS risk, which did not survive bon and fdr correction, and the obtained p-values are quite low. Therefore, further studies on larger samples are needed.

Genetic and Modifiable Risk Factors for Postoperative Complications of Total Joint Arthroplasty: A Genome-Wide Association and Mendelian Randomization Study

Background: Total joint arthroplasty (TJA) is an orthopedic procedure commonly used to treat damaged joints. Despite the efficacy of TJA, postoperative complications, including aseptic prosthesis loosening and infections, are common. Moreover, the effects of individual genetic susceptibility and modifiable risk factors on these complications are unclear. This study analyzed these effects to enhance patient prognosis and postoperative management. Methods: We conducted an extensive genome-wide association study (GWAS) and Mendelian randomization (MR) study using UK Biobank data. The cohort included 2964 patients with mechanical complications post-TJA, 957 with periprosthetic joint infection (PJI), and a control group of 398,708 individuals. Genetic loci associated with postoperative complications were identified by a GWAS analysis, and the causal relationships of 11 modifiable risk factors with complications were assessed using MR. Results: The GWAS analysis identified nine loci associated with post-TJA complications. Two loci near the PPP1R3B and RBM26 genes were significantly linked to mechanical complications and PJI, respectively. The MR analysis demonstrated that body mass index was positively associated with the risk of mechanical complications (odds ratio [OR]: 1.42; p < 0.001). Higher educational attainment was associated with a decreased risk of mechanical complications (OR: 0.55; p < 0.001) and PJI (OR: 0.43; p = 0.001). Type 2 diabetes was suggestively associated with mechanical complications (OR, 1.18, p = 0.02), and hypertension was suggestively associated with PJI (OR, 1.41, p = 0.008). Other lifestyle factors, including smoking and alcohol consumption, were not causally related to postoperative complications. Conclusions: The genetic loci near PPP1R3B and RBM26 influenced the risk of post-TJA mechanical complications and infections, respectively. The effects of genetic and modifiable risk factors, including body mass index and educational attainment, underscore the need to perform personalized preoperative assessments and the postoperative management of surgical patients. These results indicate that integrating genetic screening and lifestyle interventions into patient care can improve the outcomes of TJA and patient quality of life.

Discrepancies between general and central obesity in arterial stiffness: observational studies and Mendelian randomization study

BACKGROUND

Obesity has been linked to arterial stiffness, while no consensus was reached on the association. We aimed to clarify the association of general and central obesity with arterial stiffness by combining observational studies and Mendelian randomization (MR) study.

METHODS

Two cross-sectional studies were performed in UK Biobank and Fuqing Cohort, respectively. Two-sample MR study was conducted using summary data of GWASs from GIANT consortium and UK Biobank. General obesity and central obesity were measured using body mass index (BMI) and waist circumference (WC), respectively. Arterial stiffness was measured by arterial stiffness index (ASI) in UK Biobank or branchial-ankle pulse wave velocity (baPWV) in Fuqing Cohort.

RESULTS

Two observational studies found a consistent positive association of BMI and WC with arterial stiffness when adjusting for age, sex, education, smoking, alcohol drinking, physical activity, and LDL cholesterol. However, when additionally adjusting for metabolic traits (i.e., systolic blood pressure, diastolic blood pressure, blood glucose, triglycerides, high-density lipoprotein cholesterol, and WC or BMI), the association with BMI changed to be inverse. As compared to the lowest quintile group, the adjusted ORs across groups of second to fifth quintile were 0.93, 0.90, 0.83, and 0.72 in UK Biobank and 0.88, 0.65, 0.63, and 0.50 in Fuqing Cohort. In contrast, the positive relationship with WC remained stable with the adjusted ORs of 1.23, 1.46, 1.60, and 1.56 in UK Biobank and 1.35, 1.44, 1.77, and 1.64 in Fuqing Cohort. MR analyses provided supportive evidence of the negative association with BMI (OR = 0.97, 95%CI = 0.94-1.00) and the positive association with WC (OR = 1.14, 95%CI = 1.08-1.20).

CONCLUSIONS

Observational and genetic analyses provide concordant results that central obesity is independently related to arterial stiffness, while the role of general obesity depends on metabolic status.

Genetic determinants of obesity in Korean populations: exploring genome-wide associations and polygenic risk scores

East Asian populations exhibit a genetic predisposition to obesity, yet comprehensive research on these traits is limited. We conducted a genome-wide association study (GWAS) with 93,673 Korean subjects to uncover novel genetic loci linked to obesity, examining metrics such as body mass index, waist circumference, body fat ratio, and abdominal fat ratio. Participants were categorized into non-obese, metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) groups. Using advanced computational methods, we developed a multifaceted polygenic risk scores (PRS) model to predict obesity. Our GWAS identified significant genetic effects with distinct sizes and directions within the MHO and MUO groups compared with the non-obese group. Gene-based and gene-set analyses, along with cluster analysis, revealed heterogeneous patterns of significant genes on chromosomes 3 (MUO group) and 11 (MHO group). In analyses targeting genetic predisposition differences based on metabolic health, odds ratios of high PRS compared with medium PRS showed significant differences between non-obese and MUO, and non-obese and MHO. Similar patterns were seen for low PRS compared with medium PRS. These findings were supported by the estimated genetic correlation (0.89 from bivariate GREML). Regional analyses highlighted significant local genetic correlations on chromosome 11, while single variant approaches suggested widespread pleiotropic effects, especially on chromosome 11. In conclusion, our study identifies specific genetic loci and risks associated with obesity in the Korean population, emphasizing the heterogeneous genetic factors contributing to MHO and MUO.

Analysis of sex-biased gene expression in a Eurasian admixed population

Sex-biased gene expression differs across human populations; however, the underlying genetic basis and molecular mechanisms remain largely unknown. Here, we explore the influence of ancestry on sex differences in the human transcriptome and its genetic effects on a Eurasian admixed population: Uyghurs living in Xinjiang (XJU), by analyzing whole-genome sequencing data and transcriptome data of 90 XJU and 40 unrelated Han Chinese individuals. We identified 302 sex-biased expressed genes and 174 sex-biased cis-expression quantitative loci (sb-cis-eQTLs) in XJU, which were enriched in innate immune-related functions, indicating sex differences in immunity. Notably, approximately one-quarter of the sb-cis-eQTLs showed a strong correlation with ancestry composition; i.e. populations of similar ancestry tended to show similar patterns of sex-biased gene expression. Our analysis further suggested that genetic admixture induced a moderate degree of sex-biased gene expression. Interestingly, analysis of chromosome interactions revealed that the X chromosome acted on autosomal immunity-associated genes, partially explaining the sex-biased phenotypic differences. Our work extends the knowledge of sex-biased gene expression from the perspective of genetic admixture and bridges the gap in the exploration of sex-biased phenotypes shaped by autosome and X-chromosome interactions. Notably, we demonstrated that sex chromosomes cannot fully explain sex differentiation in immune-related phenotypes.

Cholelithiasis and cholecystectomy increase the risk of gastroesophageal reflux disease and Barrett's esophagus

Background

Cholelithiasis or cholecystectomy may contribute to the development of gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC) through bile reflux; however, current observational studies yield inconsistent findings. We utilized a novel approach combining meta-analysis and Mendelian randomization (MR) analysis, to assess the association between them.

Methods

The literature search was done using PubMed, Web of Science, and Embase databases, up to 3 November 2023. A meta-analysis of observational studies assessing the correlations between cholelithiasis or cholecystectomy, and the risk factors for GERD, BE, and EACwas conducted. In addition, the MR analysis was employed to assess the causative impact of genetic pre-disposition for cholelithiasis or cholecystectomy on these esophageal diseases.

Results

The results of the meta-analysis indicated that cholelithiasis was significantly linked to an elevated risk in the incidence of BE (RR, 1.77; 95% CI, 1.37-2.29; p < 0.001) and cholecystectomy was a risk factor for GERD (RR, 1.37; 95%CI, 1.09-1.72; p = 0.008). We observed significant genetic associations between cholelithiasis and both GERD (OR, 1.06; 95% CI, 1.02-1.10; p < 0.001) and BE (OR, 1.21; 95% CI, 1.11-1.32; p < 0.001), and a correlation between cholecystectomy and both GERD (OR, 1.04; 95% CI, 1.02-1.06; p < 0.001) and BE (OR, 1.13; 95% CI, 1.06-1.19; p < 0.001). After adjusting for common risk factors, such as smoking, alcohol consumption, and BMI in multivariate analysis, the risk of GERD and BE still persisted.

Conclusion

Our study revealed that both cholelithiasis and cholecystectomy elevate the risk of GERD and BE. However, there is no observed increase in the risk of EAC, despite GERD and BE being the primary pathophysiological pathways leading to EAC. Therefore, patients with cholelithiasis and cholecystectomy should be vigilant regarding esophageal symptoms; however, invasive EAC cytology may not be necessary.

Association of education with cholelithiasis and mediating effects of cardiometabolic factors: A Mendelian randomization study

BACKGROUND

Education, cognition, and intelligence are associated with cholelithiasis occurrence, yet which one has a prominent effect on cholelithiasis and which cardiometabolic risk factors mediate the causal relationship remain unelucidated.

AIM

To explore the causal associations between education, cognition, and intelligence and cholelithiasis, and the cardiometabolic risk factors that mediate the associations.

METHODS

Applying genome-wide association study summary statistics of primarily European individuals, we utilized two-sample multivariable Mendelian randomization to estimate the independent effects of education, intelligence, and cognition on cholelithiasis and cholecystitis (FinnGen study, 37041 and 11632 patients, respectively; n = 486484 participants) and performed two-step Mendelian randomization to evaluate 21 potential mediators and their mediating effects on the relationships between each exposure and cholelithiasis.

RESULTS

Inverse variance weighted Mendelian randomization results from the FinnGen consortium showed that genetically higher education, cognition, or intelligence were not independently associated with cholelithiasis and cholecystitis; when adjusted for cholelithiasis, higher education still presented an inverse effect on cholecystitis [odds ratio: 0.292 (95%CI: 0.171-0.501)], which could not be induced by cognition or intelligence. Five out of 21 cardiometabolic risk factors were perceived as mediators of the association between education and cholelithiasis, including body mass index (20.84%), body fat percentage (40.3%), waist circumference (44.4%), waist-to-hip ratio (32.9%), and time spent watching television (41.6%), while time spent watching television was also a mediator from cognition (20.4%) and intelligence to cholelithiasis (28.4%). All results were robust to sensitivity analyses.

CONCLUSION

Education, cognition, and intelligence all play crucial roles in the development of cholelithiasis, and several cardiometabolic mediators have been identified for prevention of cholelithiasis due to defects in each exposure.

Bi-directional association of body size and composition with heart failure: A Mendelian randomization study

PURPOSE

The effect of obesity on the development of heart failure (HF) has received attention, and this study intends to further explore the bidirectional association between body size or composition and HF by using Mendelian Randomization (MR) approach.

DESIGN

We performed a two-sample bidirectional MR study to investigate the association between body size or composition and the risk of HF using aggregated data from genome-wide association studies. Univariable MR analysis was used to investigate the causal relationship, and multivariable MR analysis was used to explore the mediating role of general and central obesity in the relationship between body size or composition and HF.

RESULTS

This forward MR study found that body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), fat mass (FM) and fat-free mass (FFM) were risk factors for the development of HF with the strength of causal association BMI > FM > WC > FFM > WHR. After adjusting for BMI, the observed associations between the remaining indicators and heart failure attenuated to null. After adjusting for WC, only BMI (OR = 1.59, 95%CI: 1.32-1.92, P = 9.53E-07) and FM (OR = 1.39, 95%CI: 1.20-1.62, P = 1.35E-0.5) kept significantly related to the risk of HF. Reverse MR analysis showed no association of changes in body size or composition with the onset of HF.

CONCLUSION

The two-sample bidirectional MR study found that general obesity, measured by BMI, was an independent indicator of the development of HF, while other related indicators were associated with HF incidence dependent on BMI, besides, no association was observed between HF diagnosis and the body size or composites.

Investigating grey matter volumetric trajectories through the lifespan at the individual level

Adolescents exhibit remarkable heterogeneity in the structural architecture of brain development. However, due to limited large-scale longitudinal neuroimaging studies, existing research has largely focused on population averages, and the neurobiological basis underlying individual heterogeneity remains poorly understood. Here we identify, using the IMAGEN adolescent cohort followed up over 9 years (14-23 y), three groups of adolescents characterized by distinct developmental patterns of whole-brain gray matter volume (GMV). Group 1 show continuously decreasing GMV associated with higher neurocognitive performances than the other two groups during adolescence. Group 2 exhibit a slower rate of GMV decrease and lower neurocognitive performances compared with Group 1, which was associated with epigenetic differences and greater environmental burden. Group 3 show increasing GMV and lower baseline neurocognitive performances due to a genetic variation. Using the UK Biobank, we show these differences may be attenuated in mid-to-late adulthood. Our study reveals clusters of adolescent neurodevelopment based on GMV and the potential long-term impact.

Type 2 Diabetes, Circulating Metabolites, and Calcific Aortic Valve Stenosis: A Mendelian Randomization Study

Epidemiological studies have shown an association between type 2 diabetes (T2D) and calcific aortic valve stenosis (CAVS), but the potential causal relationship and underlying mechanisms remain unclear. Therefore, we conducted a two-sample and two-step Mendelian randomization (MR) analysis to evaluate the association of T2D with CAVS and the mediating effects of circulating metabolites and blood pressure using genome-wide association study (GWAS) summary statistics. The inverse variance weighted (IVW) method was used for the primary MR analysis, and comprehensive sensitivity analyses were performed to validate the robustness of the results. Our results showed that genetically predicted T2D was associated with increased CAVS risk (OR 1.153, 95% CI 1.096-1.214, p < 0.001), and this association persisted even after adjusting for adiposity traits in multivariable MR analysis. Furthermore, the two-step MR analysis identified 69 of 251 candidate mediators that partially mediated the effect of T2D on CAVS, including total branched-chain amino acids (proportion mediated: 23.29%), valine (17.78%), tyrosine (9.68%), systolic blood pressure (8.72%), the triglyceride group (6.07-11.99%), the fatty acid group (4.78-12.82%), and the cholesterol group (3.64-11.56%). This MR study elucidated the causal impact of T2D on CAVS risk independently of adiposity and identified potential mediators in this association pathways. Our findings shed light on the pathogenesis of CAVS and suggest additional targets for the prevention and intervention of CAVS attributed to T2D.

A scalable and robust variance components method reveals insights into the architecture of gene-environment interactions underlying complex traits

Understanding the contribution of gene-environment interactions (GxE) to complex trait variation can provide insights into disease mechanisms, explain sources of heritability, and improve genetic risk prediction. While large biobanks with genetic and deep phenotypic data hold promise for obtaining novel insights into GxE, our understanding of GxE architecture in complex traits remains limited. We introduce a method to estimate the proportion of trait variance explained by GxE (GxE heritability) and additive genetic effects (additive heritability) across the genome and within specific genomic annotations. We show that our method is accurate in simulations and computationally efficient for biobank-scale datasets. We applied our method to common array SNPs (MAF ≥1%), fifty quantitative traits, and four environmental variables (smoking, sex, age, and statin usage) in unrelated white British individuals in the UK Biobank. We found 68 trait-E pairs with significant genome-wide GxE heritability (p<0.05/200) with a ratio of GxE to additive heritability of ≈6.8% on average. Analyzing ≈8 million imputed SNPs (MAF ≥0.1%), we documented an approximate 28% increase in genome-wide GxE heritability compared to array SNPs. We partitioned GxE heritability across minor allele frequency (MAF) and local linkage disequilibrium (LD) values, revealing that, like additive allelic effects, GxE allelic effects tend to increase with decreasing MAF and LD. Analyzing GxE heritability near genes highly expressed in specific tissues, we find significant brain-specific enrichment for body mass index (BMI) and basal metabolic rate in the context of smoking and adipose-specific enrichment for waist-hip ratio (WHR) in the context of sex.

Mendelian randomization analyses clarify the effects of height on cardiovascular diseases

An inverse correlation between stature and risk of coronary artery disease (CAD) has been observed in several epidemiologic studies, and recent Mendelian randomization (MR) experiments have suggested causal association. However, the extent to which the effect estimated by MR can be explained by cardiovascular, anthropometric, lung function, and lifestyle-related risk factors is unclear, with a recent report suggesting that lung function traits could fully explain the height-CAD effect. To clarify this relationship, we utilized a well-powered set of genetic instruments for human stature, comprising >1,800 genetic variants for height and CAD. In univariable analysis, we confirmed that a one standard deviation decrease in height (~6.5 cm) was associated with a 12.0% increase in the risk of CAD, consistent with previous reports. In multivariable analysis accounting for effects from up to 12 established risk factors, we observed a >3-fold attenuation in the causal effect of height on CAD susceptibility (3.7%, p = 0.02). However, multivariable analyses demonstrated independent effects of height on other cardiovascular traits beyond CAD, consistent with epidemiologic associations and univariable MR experiments. In contrast with published reports, we observed minimal effects of lung function traits on CAD risk in our analyses, indicating that these traits are unlikely to explain the residual association between height and CAD risk. In sum, these results suggest the impact of height on CAD risk beyond previously established cardiovascular risk factors is minimal and not explained by lung function measures.

Systems genetics analysis of human body fat distribution genes identifies adipocyte processes

Excess abdominal fat is a sexually dimorphic risk factor for cardio-metabolic disease and is approximated by the waist-to-hip ratio adjusted for body mass index (WHRadjBMI). Whereas this trait is highly heritable, few causal genes are known. We aimed to identify novel drivers of WHRadjBMI using systems genetics. We used two independent cohorts of adipose tissue gene expression and constructed sex- and depot-specific Bayesian networks to model gene-gene interactions from 8,492 genes. Using key driver analysis, we identified genes that, in silico and putatively in vitro, regulate many others. 51-119 key drivers in each network were replicated in both cohorts. In other cell types, 23 of these genes are found in crucial adipocyte pathways: Wnt signaling or mitochondrial function. We overexpressed or down-regulated seven key driver genes in human subcutaneous pre-adipocytes. Key driver genes ANAPC2 and RSPO1 inhibited adipogenesis, whereas PSME3 increased adipogenesis. RSPO1 increased Wnt signaling activity. In differentiated adipocytes, MIGA1 and UBR1 down-regulation led to mitochondrial dysfunction. These five genes regulate adipocyte function, and we hypothesize that they regulate fat distribution.

Evaluating Sex-specific Differences in Abdominal Fat Volume and Proton Density Fat Fraction at MRI Using Automated nnU-Net-based Segmentation

Sex-specific abdominal organ volume and proton density fat fraction (PDFF) in people with obesity during a weight loss intervention was assessed with automated multiorgan segmentation of quantitative water-fat MRI. An nnU-Net architecture was employed for automatic segmentation of abdominal organs, including visceral and subcutaneous adipose tissue, liver, and psoas and erector spinae muscle, based on quantitative chemical shift-encoded MRI and using ground truth labels generated from participants of the Lifestyle Intervention (LION) study. Each organ's volume and fat content were examined in 127 participants (73 female and 54 male participants; body mass index, 30-39.9 kg/m2) and in 81 (54 female and 32 male participants) of these participants after an 8-week formula-based low-calorie diet. Dice scores ranging from 0.91 to 0.97 were achieved for the automatic segmentation. PDFF was found to be lower in visceral adipose tissue compared with subcutaneous adipose tissue in both male and female participants. Before intervention, female participants exhibited higher PDFF in subcutaneous adipose tissue (90.6% vs 89.7%; P < .001) and lower PDFF in liver (8.6% vs 13.3%; P < .001) and visceral adipose tissue (76.4% vs 81.3%; P < .001) compared with male participants. This relation persisted after intervention. As a response to caloric restriction, male participants lost significantly more visceral adipose tissue volume (1.76 L vs 0.91 L; P < .001) and showed a higher decrease in subcutaneous adipose tissue PDFF (2.7% vs 1.5%; P < .001) than female participants. Automated body composition analysis on quantitative water-fat MRI data provides new insights for understanding sex-specific metabolic response to caloric restriction and weight loss in people with obesity. Keywords: Obesity, Chemical Shift-encoded MRI, Abdominal Fat Volume, Proton Density Fat Fraction, nnU-Net ClinicalTrials.gov registration no. NCT04023942 Supplemental material is available for this article. Published under a CC BY 4.0 license.

Relationship of Fat Mass Ratio, a Biomarker for Lipodystrophy, With Cardiometabolic Traits

Familial partial lipodystrophy (FPLD) is a heterogenous group of syndromes associated with a high prevalence of cardiometabolic diseases. Prior work has proposed DEXA-derived fat mass ratio (FMR), defined as trunk fat percentage divided by leg fat percentage, as a biomarker of FPLD, but this metric has not previously been characterized in large cohort studies. We set out to 1) understand the cardiometabolic burden of individuals with high FMR in up to 40,796 participants in the UK Biobank and 9,408 participants in the Fenland study, 2) characterize the common variant genetic underpinnings of FMR, and 3) build and test a polygenic predictor for FMR. Participants with high FMR were at higher risk for type 2 diabetes (odds ratio [OR] 2.30, P = 3.5 × 10-41) and metabolic dysfunction-associated liver disease or steatohepatitis (OR 2.55, P = 4.9 × 10-7) in UK Biobank and had higher fasting insulin (difference 19.8 pmol/L, P = 5.7 × 10-36) and fasting triglycerides (difference 36.1 mg/dL, P = 2.5 × 10-28) in the Fenland study. Across FMR and its component traits, 61 conditionally independent variant-trait pairs were discovered, including 13 newly identified pairs. A polygenic score for FMR was associated with an increased risk of cardiometabolic diseases. This work establishes the cardiometabolic significance of high FMR, a biomarker for FPLD, in two large cohort studies and may prove useful in increasing diagnosis rates of patients with metabolically unhealthy fat distribution to enable treatment or a preventive therapy.

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