Genome-wide association studies and Mendelian randomization analyses for leisure sedentary behaviours

The impact of leisure sedentary behaviors on risk of chronic kidney disease, diabetes, and related complications: Mendelian randomization study

BACKGROUND

The causal relationship between leisure sedentary behaviors (LSBs) and chronic kidney disease, diabetes and related complications is still equivocal. In this study, we performed two-sample Mendelian randomization for declaring the potential causal association between LSBs and these diseases and summarized the causal estimates.

METHODS

In this study, we used GWAS summary statistics from the public database for exposures (LSB: television watching, computer use, and driving) and outcomes (chronic kidney diseases, diabetes mellitus, and related complications). To ensure reliable results for this study, we applied several methods including IVW, MR-Egger, and weighted median for the regression process; MR-Egger intercept test, Cochran's Q test, 'leave-one-out' analysis and MR-PRESSO test were used to detect horizontal pleiotropy and heterogeneity for sensitivity analysis.

RESULTS

Television watching was harmful of CKD (OR = 1.26, 95%CI 1.09-1.44; p = 0.0011), T2D (OR = 1.82, 95%CI 1.48-2.24; p = 1.67e - 08) and DM (OR = 2.26, 95%CI 1.75-2.93; p = 6.44e - 10). No horizontal pleiotropy was detected in MR-Egger intercept test (p value > 0.05) and there were no influential SNPs based on 'leave-one-out' analysis.

CONCLUSIONS

Mendelian randomization estimates in our study genetically predicted the causal effect between television watching and CKD, T2D, and DM. However, we cannot get the definitive causal effect of television watching and other related complications, further studies need to be done to explore the mechanism of action of sedentary behavior on the complications of diabetes and chronic kidney disease.

Uncovering covariance patterns across energy balance traits enables the discovery of new obesity-related genes

OBJECTIVE

Effective solutions to obesity remain elusive, partly owing to its root in a positive energy balance (EB), which stems from the interplay of numerous traits spanning body size and composition, diet, physical activity, and metabolic profile. Nevertheless, EB-contributing traits are typically studied in isolation. We integrate numerous EB-related traits measured in the UK Biobank to uncover the underlying patterns of EB and associated genes in study participants.

METHODS

We used sparse factor analysis to integrate traits and performed genome-wide association analyses on the integrated phenotypes to elucidate EB-related genes and metabolic pathways. We performed pleiotropy analyses on candidate single-nucleotide polymorphisms to uncover the genetic basis of EB.

RESULTS

We identified multiple genes and genomic regions associated with EB, including many that have previously not been directly associated with obesity measures (e.g., MIR5591, FNDC3B, ANAPC10, SULT1A1, AXIN1, SKIDA1, ERLIN1, DOCK7), which we validated using an independent subset of the UK Biobank dataset along with data from the Atherosclerosis Risk in Communities cohort. We found that the covariances in EB traits are primarily driven by genome-wide pleiotropic associations.

CONCLUSIONS

We offer new insight into EB patterns and the genetic basis of EB.

Genetic liability to sedentary behaviour and cardiovascular disease incidence in the FinnGen and HUNT cohorts

OBJECTIVE

Energy-saving sedentary behaviour may be an evolutionarily selected trait that is no longer advantageous. We investigated the associations between genetic liability to sedentary behaviour and the incidence of the most common cardiovascular disease (CVD).

METHODS

We constructed and validated a genome-wide polygenic score for leisure screen time (PGS LST) as a measure of genetic liability to sedentary behaviour. We performed survival analyses between higher PGS LST and register-based CVDs using the FinnGen cohort (N=293 250-333 012). Replication and exploratory analyses were conducted in an independent Norwegian Trøndelag Health Study (HUNT) cohort (N=35 289).

RESULTS

In FinnGen, each SD increase in PGS LST was associated with a higher risk of incident CVD (HR: 1.05 (95% CI 1.05 to 1.06)) (168 770 cases over 17 101 133 person-years). The magnitudes of association for the three most common CVDs were 1.09 ((95% CI 1.08 to 1.09), 1.06 ((95% CI 1.05 to 1.07) and 1.05 ((95% CI 1.04 to 1.06) for hypertensive disease, ischaemic heart disease and cerebrovascular disease, respectively. Those in the top decile of PGS LST had 21%, 35%, 26% and 19% higher risk of any CVD, hypertensive disease, ischaemic heart disease and cerebrovascular disease, respectively, than those in the bottom decile. Associations were replicated in HUNT and remained independent of covariates (socioeconomic status, body mass index and smoking) except for cerebrovascular disease. Besides direct effects, reduced physical activity served as a potential mediating pathway for the observed associations.

CONCLUSIONS

We found that genetic liability to sedentary behaviour is associated with incident CVD, although effect sizes with current PGS remained small. These findings suggest that genetic liability to sedentary behaviour is an under-recognised driver of common CVDs.

Placental weight as a predictor of future health: Insights from a large-scale genome-wide association study

INTRODUCTION

Placental weight has been associated with various adult-onset diseases, but the causal relationships and underlying mechanisms remain unclear.

METHODS

This two-sample Mendelian randomization (MR) study utilized genome-wide association study (GWAS) data from multiple independent cohorts, primarily of European ancestry. The analysis included over 1.8 million individuals for type 2 diabetes mellitus (T2DM) outcomes. Data from four independent cohorts were used for validation. The inverse variance-weighted method was used for primary analysis, with weighted median, weighted mode, and MR-Egger regression for sensitivity analyses.

RESULTS

Each standard deviation increase in genetically predicted placental weight was associated with T2DM (β = -0.109, 95 % CI: -0.184 to -0.034), basal cell carcinoma (β = 0.130, 95 % CI: 0.016 to 0.245), acute upper respiratory infections (β = -0.062, 95 % CI: -0.113 to -0.011), neurological diseases (β = -0.009, 95 % CI: -0.014 to -0.003), and endometrial cancer (β = -0.561, 95 % CI: -0.961 to -0.161). Placental weight also showed significant negative associations with blood glucose levels (β = -0.102, 95 % CI: -0.200 to -0.004). Mediation analyses revealed that dried fruit intake mediated 14.68 % of the total effect on T2DM risk, while immune cell phenotype analysis identified HLA DR on CD33dim HLA DR + CD11b + as a potential mediator in the causal pathway.

CONCLUSION

This study provides genetic evidence for a causal relationship between placental weight and T2DM risk, mediated partly through dietary habits and immune pathways. These findings suggest that early-life placental development may influence long-term metabolic health, highlighting the importance of prenatal care in preventing adult-onset diseases.

Mediating factors in the association between educational attainment and stroke: A mendelian randomization study

Background

Stroke is a common cardiovascular and cerebrovascular disease with high disability and mortality. Lower educational attainment has been reported to be associated with an increased risk of stroke, but it is unclear which pathways mediate this association.

Methods

Using genome-wide association studies (GWAS) based on European ancestry, we performed two-sample Mendelian randomization (MR) analyses to investigate the causal association of genetically estimated educational attainment with stroke and its subtypes. Then, we used mediation analyses to assess the extent to which seven cardiometabolic risk factors alone and in combination explain their effects.

Results

Genetically estimated educational attainment was negatively associated with the risk of any stroke (AS), any ischemic stroke (AIS), ischemic stroke subtypes (large artery stroke [LAS], cardioembolic stroke [CES], and small vessel stroke [SVS]), and hemorrhagic stroke subtypes (cerebral hemorrhage [ICH] and subarachnoid hemorrhage [SAH]). For individual mediating effects, type 2 diabetes, hypertension, hyperlipidemia, and smoking mediated the impact of education on AS, AIS, and ischemic stroke subtypes, while obesity, NAFLD, and alcohol consumption played no role. For combined mediation, the proportion of the association that cardiometabolic mediators explained ranged from 4% (95% CI: 2.72%-5.27%) for SVS to 38.73% (95% CI: 37.42%-40.05%) for LAS. Nevertheless, they did not account for any of the estimates for hemorrhagic stroke subtypes.

Conclusion

Higher educational attainment would have a protective effect on stroke and its subtypes, and cardiometabolic risk factors mediated part proportion of this association. Hence, patients with low education should pay more attention to managing cardiometabolic diseases to prevent stroke.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Mendelian randomization studies of risk and protective factors for osteoporosis: a systematic review and meta-analysis

Background

Mendelian randomization is believed to attenuate the biases inherent in observational studies, yet a meta-analysis of Mendelian randomization studies in osteoporosis has not been conducted thus far. This study aims to evaluate the connection between potential causal factors and the risk of osteoporosis by synthesizing evidence from Mendelian randomization studies.

Methods

The databases PubMed, Web of Science, and Embase were systematically searched for Mendelian randomization studies investigating factors influencing osteoporosis up to May 2024. Meta-analyses were conducted to assess the associations between various potential pathogenic factors and osteoporosis using Mendelian Randomization studies. The quality of the study was evaluated according to the Strengthening the Reporting of Observational Studies in Epidemiology via Mendelian Randomization (STROBE-MR) guidelines.

Results

A total of 706 potentially relevant articles were screened, resulting in the inclusion of 53 studies in the systematic review, of which 30 were eligible for the meta-analysis. The combined findings from these 30 studies revealed that rheumatoid arthritis, inflammatory bowel disease, sex hormone binding globulin, depression, non-alcoholic fatty liver disease, primary biliary cholangitis and asthma are associated with increased risk of osteoporosis, while basal metabolic rate and gut microbiota (NB1n) serves as a protective factor. However, the association between obesity, type 2 diabetes mellitus, metformin, ulcerative colitis, leisure sedentary behaviors, systemic lupus erythematosus, serum iron and osteoporosis was found to be nonsignificant.

Conclusion

In summary, our meta-analysis indicates that significant causal relationships with osteoporosis's onset and progression have been established for rheumatoid arthritis, inflammatory bowel disease, primary biliary cholangitis, non-alcoholic fatty liver disease, depression, sex hormone binding globulin, basal metabolic rate, gut microbiota (NB1n), and asthma.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier PROSPERO CRD42024540504.

The zinc-finger protein POGZ associates with Polycomb repressive complex 1 to regulate bone morphogenetic protein signaling during neuronal differentiation

Polycomb Repressive Complex 1 (PRC1) is a family of epigenetic regulators critical for mammalian development. Elucidating PRC1 composition and function across cell types and developmental stages is key to understanding the epigenetic regulation of cell fate determination. In this study, we discovered POGZ, a prominent Autism Spectrum Disorder (ASD) risk factor, as a novel component of PRC1.6, forming the PRC1.6-POGZ complex. Functional assays revealed that POGZ elicits transcriptional repression that is dependent on RING1B expression. Analysis of publicly available ChIP-Seq data showed that POGZ highly colocalizes with RING1B and HP1γ, two PRC1.6 components, at genes involved in multiple aspects of transcriptional regulation in the embryonic mouse cortex. Although Pogz knockout (KO) does not compromise stem cell pluripotency, Pogz ablation in neuronal progenitor cells (NPCs) led to widespread transcriptomic dysregulation with failed activation of key neuronal genes. Finally, we demonstrated that PRC1.6-POGZ regulates neuronal differentiation by repressing the bone morphogenetic protein (BMP) signaling pathway. These findings reveal a mechanism by which PRC1 and POGZ coordinate transcriptional regulation during neuronal differentiation, which offers insights into how disruptions in this pathway may contribute to neurodevelopmental disorders such as ASD.

Association between physical activity and sedentary behavior and gestational diabetes mellitus: a Mendelian randomization analysis

Introduction

The evidence of association between physical activity (PA), sedentary behavior (SB) and gestational diabetes mellitus (GDM) remains controversial in observational studies, this study aimed to generate new hypotheses between PA, SB and GDM.

Methods

Our study performed Mendelian randomization (MR) analysis to explore the effects of three types of PA (moderate physical activity (MPA), moderate to vigorous physical activity (MVPA), accelerometer-based physical activity (ABPA)), three types of SB (television watching (TV), leisure computer use (PC), driving (DR)) on GDM and the mediating effect of body mass index (BMI). The inverse variance weighted method was used for the major analysis.

Results

In univariate MR analysis, we found that genetically predicted TV and PC among SB were associated with GDM (OR = 1.61, 95%CI 1.21-2.14, P = 0.001; OR = 0.71, 95%CI 0.51-0.98, P = 0.037), whereas DR and MP were not (OR = 1.68, 95%CI 0.21-13.3, P = 0.623; OR = 1.20, 95%CI 0.87-1.65, P = 0.271). However, no association was found between physical activity and GDM: MPA (OR = 0.40, 95%CI 0.08-2.06, P = 0.273), MVPA (OR = 0.96, 95%CI 0.58-1.57, P = 0.861), and ABPA (OR = 0.99, 95%CI 0.90-1.09, P = 0.838). Multivariate MR analysis found DM (OR = 1.64, 95%CI 1.13-2.36, P = 0.008) and that BMI was a mediating factor with a 62% mediating effect.

Conclusions

This study proposes a new hypothesis for the association between TV and GDM, which is mediated by BMI, providing evidence for reducing the risk of GDM during pregnancy by reducing television watching time.

Causal Association Between Sedentary Behaviors and Health Outcomes: A Systematic Review and Meta-Analysis of Mendelian Randomization Studies

BACKGROUND

Different types of sedentary behavior are associated with several health outcomes, but the causality of these associations remains unclear.

OBJECTIVES

To conduct a systematic review and meta-analysis of Mendelian randomization (MR) studies investigating the associations between sedentary behaviors and health outcomes.

METHODS

A systematic search on PubMed, Embase, Web of Science, Scopus, and PsycINFO up to August 2023 was conducted to identify eligible MR studies. We selected studies that assessed associations of genetically determined sedentary behaviors and health outcomes. A meta-analysis was conducted to examine the causal associations when two or more MR studies were available. We graded the evidence level of each MR association based on the results of the main method and sensitivity analyses in MR studies.

RESULTS

A total of 31 studies with 168 MR associations between six types of sedentary behavior and 47 health outcomes were included. Results from meta-analyses suggested a total of 47 significant causal associations between sedentary behaviors and health outcomes. Notably, more leisure TV watching is robustly correlated with increased risks of myocardial infarction, coronary artery disease, all-cause ischemic stroke, and type 2 diabetes. Conversely, robust inverse associations were observed between leisure computer use and risks of rheumatoid arthritis, Alzheimer's disease, and gastroesophageal reflux disease.

CONCLUSION

These findings suggest that different types of sedentary behavior have distinct causal effects on health outcomes. Therefore, interventions should focus not only on reducing sedentary time but also on promoting healthier types of sedentary behavior.

PROSPERO REGISTRATION

CRD42023453828.

The potential association between sedentary behaviors and risk of temporomandibular disorders: evidence from Mendelian randomization analysis

The role of sedentary behaviors in temporomandibular disorders (TMD) has not been thoroughly investigated. This study aims to investigate the potential association between sedentary behaviors and TMD using Mendelian randomization (MR) analysis. The MR method was employed to assess the causal association between sedentary behaviors and the risk of TMD. Genetic variants associated with sedentary behaviors, such as watching TV (Television), using computers and driving, were used as instrumental variables (IVs). MR analysis was performed using inverse variance-weighted (IVW) and weighted median methods, alongside MR-Egger regression to assess pleiotropy and statistical heterogeneity. Furthermore, leave-one-out analyses were conducted to assess whether any single SNP (single nucleotide polymorphism) or subset of SNPs influenced the results. Our analysis identified a significant association between driving time and the risk of temporomandibular disorders (IVW: OR (Odd ratio) = 2.797, 95% CI (Confidence interval) = 1.148-6.811, p = 0.024; weighted median OR = 4.271, 95% CI = 1.226-14.871, p = 0.023). In contrast, no significant associations were observed between time spent watching TV and using a computer and TMD risk. The robustness of the findings was confirmed through sensitivity analyses, including leave-one-out analysis. This study provides evidence of a potential genetic link between prolonged driving and TMD risk, suggesting that individuals frequently engaged in long-duration driving should be monitored for TMD symptoms. Further research is warranted to explore the complex interactions between sedentary behaviors and TMD, incorporating longitudinal and comprehensive assessments.

The association among multiple-site chronic pain, sedentary behavior, and major depressive disorders: a mendelian randomization study

OBJECTIVE

Observational studies have reported that major depressive disorder (MDD) is associated with sedentary behavior (SB) and multiple chronic pain (MCP), but their associations remain unclear. Mendelian randomization analysis was used to assess the association.

METHODS

Single nucleotide polymorphisms (SNPs) associated with MCP, SB [time spent watching television (Tel), using a computer (Com), or driving (Dri)], and MDD were collected from genome-wide association studies and screened as instrumental variants with a threshold of 1 × 10 -5 . Mendelian randomization was performed to examine their associations. Sensitivity analyses were conducted to evaluate robustness.

RESULTS

MCP was associated with a higher risk of MDD [odds ratio (OR) inverse variance weighting (IVW)  = 1.88; 95% confidence interval (CI), 1.64-2.15; P  = 4.26 × 10 -8 ), and causally related to SB (Tel: OR IVW  = 1.23; 95% CI, 1.19-1.26; P  = 6.02 × 10 -38 ) (Dri: OR IVW  = 1.05; 95% CI, 1.03-1.08; P  = 3.92 × 10 -5 ). Causality of SB on MCP was detected for Tel (OR IVW  = 1.46; 95% CI, 1.39-1.53; P  = 1.40 × 10 -54 ) and Com (OR IVW  = 0.88; 95% CI, 0.83-0.93; P  = 2.50 × 10 -6 ). No association was observed for SB on MDD. There is currently insufficient evidence to support that leisure activities are a mediating factor in MCP-induced MDD.

CONCLUSION

There are complex relationships among MCP, SB, and MDD. More research and learning about potential relationships and mechanisms among these phenotypes should be supplied.

Genetic proxies for therapy of insulin drug targets and risk of osteoarthritis: a drug-target Mendelian randomization analysis

BACKGROUND

The potential effects of insulin therapy on osteoarthritis (OA) risk are poorly understood. This study aimed to explore the causal relationship between insulin therapy and OA.

METHODS

Mendelian randomization (MR) analysis was performed to examine the association between genetically proxied inhibition of insulin targets and the risk of overall, hip (HOA) and knee OA (KOA). We then performed univariable MR using summary statistics regarding insulin target genes derived from the DrugBank database. Data related to blood glucose reduction levels were used as a proxy for insulin levels. Two phenotypes, type 2 diabetes, and glycosylated hemoglobin levels, were selected as positive controls to confirm the direction and validity of the proxies. The OA datasets were derived from the UK Biobank cohort. Multivariable MR was adjusted for body mass index, sedentary behavior, cigarette smoking, frequency of alcohol intake, age, and genetic sex.

RESULTS

Genetically proxied insulin therapy was associated with an increased risk of overall OA [odds ratio (OR):1.2595; 95% confidence interval (CI):1.0810-1.4675] and HOA (OR:1.4218; 95%CI:1.1240-1.7985), which remained consistent across multiple MR methods. After adjusting for confounders, we found evidence supporting a significant causal link with a higher risk of overall OA and HOA. A further two-step MR analysis revealed no significant mediation effects from the six mediators in the associations.

CONCLUSION

There was a causal association between genetically proxied insulin therapy and a higher risk of OA, especially HOA.

A Mendelian randomization study on causal effects of leisure sedentary behavior on the risk of erectile dysfunction

BACKGROUND

Erectile dysfunction has been associated with leisure sedentary behavior in several epidemiological and observational studies. However, the interpretation of these findings is difficult due to residual confounding or reverse causality.

OBJECTIVES

To explore the causal association between leisure sedentary behavior and erectile dysfunction, and to explore the underlying mechanism using Mendelian randomization.

MATERIALS AND METHODS

In the present study, publicly available large-scale genome-wide association studies of leisure sedentary behaviors (television watching, computer use, and driving), erectile dysfunction, sex hormones (total testosterone, bioactive testosterone, estradiol, follicle-stimulating hormone, luteinizing hormone, prolactin, and sex hormone binding globulin), biomarkers of endothelial function (C reactive protein, E-selectin, and matrix metalloproteinase 7), and psychiatric symptoms (depression and anxiety) were used to perform two-sample Mendelian randomization analyses. The inverse variance weighting method was the main method used to estimate the association, and sensitivity analyses were also performed.

RESULTS

A greater risk of erectile dysfunction was significantly associated with a higher genetic susceptibility to leisure computer usage (odds ratio = 3.57; 95% confidence interval = 1.78-7.16; p < 0.001). No evidence was obtained to suggest that watching television or driving for leisure increased the risk of erectile dysfunction. No association was found between computer use and depression, anxiety, C reactive protein, E-selectin, matrix metalloproteinase 7, or other sex hormones, with the exception of follicle-stimulating hormone levels (odds ratio = 0.29; 95% confidence interval = 0.12-0.69; p = 0.01). No indication of heterogeneity or pleiotropy was identified by sensitivity analysis.

DISCUSSION

Extended computer usage for leisure raised the likelihood of developing erectile dysfunction, which may be associated to lower follicle-stimulating hormone levels; however, the role of endothelial dysfunction and psychological disorders in the development of erectile dysfunction should not be underestimated. Moderate physical activity may help to correct the dysfunction.

CONCLUSION

The present study offered substantial evidence for a positive causal association between computer use and the risk of erectile dysfunction. However, a definitive causal association needs to be established by further research.

Causal effect of physical activity and sedentary behavior on the risk of alcohol dependence: A bidirectional two-sample Mendelian randomization study

BACKGROUND

Alcohol dependence, influenced by physical activity (PA) and sedentary behavior, lacks clear causal clarity. This study aims to clarify causal relationships by estimating these effects using bidirectional two-sample Mendelian randomization (MR).

METHODS

A bidirectional multivariable two-sample MR framework was employed to assess the causal effects of PA and sedentary behavior on alcohol dependence. Summarized genetic association data were analyzed for four PA-related activity patterns-moderate to vigorous physical activity (MVPA), vigorous physical activity (VPA), accelerometer-based physical activity with average acceleration (AccAve), and accelerometer-based physical activity with accelerations greater than 425 milli-gravities (Acc425)-and three sedentary behavior patterns-sedentary, TV watching, and computer use. The study was expanded to include the examination of the relationship between sedentary behavior or PA and general drinking behavior, quantified as drinks per week (DPW). We obtained summarized data on genetic associations with four PA related activity patterns (MVPA, VPA, AccAve and Acc425) and three sedentary behavior related behavior patterns (sedentary, TV watching and computer use).

RESULTS

MR analysis found AccAve inversely associated with alcohol dependence risk (OR: 0.87; 95% CI: 0.80-0.95; p < 0.001), MVPA positively associated (OR: 2.86; 95%CI: 1.45-5.66; p = 0.002). For sedentary behavior and alcohol dependence, only TV watching was positively associated with the risk of alcohol dependence (OR: 1.43; 95%CI: 1.09-1.88; p = 0.009). No causal links found for other physical or sedentary activities. Reverse analysis and sensitivity tests showed consistent findings without pleiotropy or heterogeneity. Multivariate MR analyses indicated that while MVPA, AccAve and TV watching are independently associated with alcohol dependence, DPW did not show a significant causal relationship.

CONCLUSIONS

Our results suggest that AccAve is considered a protective factor against alcohol dependence, while MVPA and TV watching are considered risk factors for alcohol dependence. Conversely, alcohol dependence serves as a protective factor against TV watching. Only TV watching and alcohol dependence might mutually have a significant causal effect on each other.

Causal Relationship between Television Viewing Time, Cardiovascular Diseases, and Potential Mechanisms

BACKGROUND

As the predominant leisure-time sedentary behavior, television viewing was documented to increase cardiovascular diseases in observational studies, yet the causal relationship and potential mechanisms remain to be determined.

OBJECTIVES

To systematically investigate the causal relationship between television viewing time, cardiovascular diseases, and potential mechanisms.

METHODS

We conducted a two-sample Mendelian randomization (MR) analysis to estimate causal associations with cardiovascular diseases and biomarkers of cardiometabolic risk. The random inverse-variance weighted method was used as the primary estimate. To account for multiple comparisons, a Bonferroni correction p value for cardiovascular diseases and biomarkers of cardiometabolic risk was 0.0045 and 0.0024, respectively.

RESULTS

Genetically instrumented television viewing time was associated with higher risks of type 2 diabetes (odd ratio [OR]=2.51; 95% confidence interval [CI]: 1.89-3.33; p<0.00001), hypertension (OR=2.11; 95% CI: 1.67-2.66; p<0.00001), coronary heart disease (OR=1.53; 95% CI: 1.23-1.91; p=0.00015), and heart failure (OR=1.42; 95% CI: 1.18-1.70; p=0.00017). Suggestive evidence of harmful associations was also observed for peripheral artery disease (OR=1.58; 95% CI: 1.07-2.34; p=0.02253) and ischemic stroke (OR=1.34; 95% CI: 1.10-1.63; p=0.00328). Biomarkers of cardiometabolic risk, including interleukin 10, leptin, visceral adipose, abdominal subcutaneous adipose, liver fat, body mass index, waist circumference, triglycerides, and C-reactive protein, were increased. Systolic blood pressure, heart rate, low-density lipoprotein, and total cholesterol were potentially increased while high-density lipoprotein was decreased. However, television viewing time had no effect on venous thromboembolism or pulmonary embolism.

CONCLUSION

Television viewing time was causally associated with increased risks of cardiovascular diseases, which may be explained by metabolic and inflammatory mechanisms.

BACKGROUND

An overview of the effect of television viewing time on cardiovascular diseases and biomarkers of cardiometabolic risk.

Mediating pathways between attention deficit hyperactivity disorder and type 2 diabetes mellitus: evidence from a two-step and multivariable Mendelian randomization study

AIMS

Type 2 diabetes (T2D) is a global health burden, more prevalent among individuals with attention deficit hyperactivity disorder (ADHD) compared to the general population. To extend the knowledge base on how ADHD links to T2D, this study aimed to estimate causal effects of ADHD on T2D and to explore mediating pathways.

METHODS

We applied a two-step, two-sample Mendelian randomization (MR) design, using single nucleotide polymorphisms to genetically predict ADHD and a range of potential mediators. First, a wide range of univariable MR methods was used to investigate associations between genetically predicted ADHD and T2D, and between ADHD and the purported mediators: body mass index (BMI), childhood obesity, childhood BMI, sedentary behaviour (daily hours of TV watching), blood pressure (systolic blood pressure, diastolic blood pressure), C-reactive protein and educational attainment (EA). A mixture-of-experts method was then applied to select the MR method most likely to return a reliable estimate. We used estimates derived from multivariable MR to estimate indirect effects of ADHD on T2D through mediators.

RESULTS

Genetically predicted ADHD liability associated with 10% higher odds of T2D (OR: 1.10; 95% CI: 1.02, 1.18). From nine purported mediators studied, three showed significant individual mediation effects: EA (39.44% mediation; 95% CI: 29.00%, 49.73%), BMI (44.23% mediation; 95% CI: 34.34%, 52.03%) and TV watching (44.10% mediation; 95% CI: 30.76%, 57.80%). The combination of BMI and EA explained the largest mediating effect (53.31%, 95% CI: -1.99%, 110.38%) of the ADHD-T2D association.

CONCLUSIONS

These findings suggest a potentially causal, positive relationship between ADHD liability and T2D, with mediation through higher BMI, more TV watching and lower EA. Intervention on these factors may thus have beneficial effects on T2D risk in individuals with ADHD.

Genomic structural equation modeling reveals latent phenotypes in the human cortex with distinct genetic architecture

Genetic contributions to human cortical structure manifest pervasive pleiotropy. This pleiotropy may be harnessed to identify unique genetically-informed parcellations of the cortex that are neurobiologically distinct from functional, cytoarchitectural, or other cortical parcellation schemes. We investigated genetic pleiotropy by applying genomic structural equation modeling (SEM) to map the genetic architecture of cortical surface area (SA) and cortical thickness (CT) for 34 brain regions recently reported in the ENIGMA cortical GWAS. Genomic SEM uses the empirical genetic covariance estimated from GWAS summary statistics with LD score regression (LDSC) to discover factors underlying genetic covariance, which we are denoting genetically informed brain networks (GIBNs). Genomic SEM can fit a multivariate GWAS from summary statistics for each of the GIBNs, which can subsequently be used for LD score regression (LDSC). We found the best-fitting model of cortical SA identified 6 GIBNs and CT identified 4 GIBNs, although sensitivity analyses indicated that other structures were plausible. The multivariate GWASs of the GIBNs identified 74 genome-wide significant (GWS) loci (p < 5 × 10-8), including many previously implicated in neuroimaging phenotypes, behavioral traits, and psychiatric conditions. LDSC of GIBN GWASs found that SA-derived GIBNs had a positive genetic correlation with bipolar disorder (BPD), and cannabis use disorder, indicating genetic predisposition to a larger SA in the specific GIBN is associated with greater genetic risk of these disorders. A negative genetic correlation was observed between attention deficit hyperactivity disorder (ADHD) and major depressive disorder (MDD). CT GIBNs displayed a negative genetic correlation with alcohol dependence. Even though we observed model instability in our application of genomic SEM to high-dimensional data, jointly modeling the genetic architecture of complex traits and investigating multivariate genetic links across neuroimaging phenotypes offers new insights into the genetics of cortical structure and relationships to psychopathology.

Genetically-predicted effects of lifestyle factors on frailty: Evidence from Mendelian randomization study

OBJECTIVE

To evaluate the causal relationships between genetically predicted lifestyle factors and frailty using Mendelian randomization(MR).

METHODS

We extracted summary data from genome-wide association studies conducted among individuals of European ancestry, examining lifestyle factors such as smoking, alcohol consumption, physical activity, and sedentary behaviors. The outcomes were assessed using Fried Frailty Score (FFS) and Frailty Index (FI). We conducted 2-sample single-variable Mendelian randomization (SVMR) and multivariable Mendelian randomization (MVMR) to simultaneously assess the independent causal effects were primarily estimated using inverse variance weighted methods. Multiple sensitivity and validation analyzes were used.

RESULTS

The IVW analyzes indicated that smoking increased frailty risk (FFS: β = 0.107, 95 % CI = 0.057 to 0.156, P < 0.001; FI: β = 0.899, 95 % CI = 0.016 to 0.191, P = 0.020.), this effect was amplified in the MVMR analysis after adjusting for alcohol consumption. Strenuous sports or other exercise(SSOE) reduced frailty risk (FFS: β = -0.473, 95 % CI = -0.646 to -0.299, P < 0.001; FI: β = -0.423, 95 % CI = -0.692 to -0.154, P = 0.002). Vigorous and moderate-to-vigorous physical activities were significantly related to lower FFS, although no effects were observed on FI. Increased television watching was linked to higher frailty incidence (FFS: β = 0.227, 95 % CI = 0.197 to 0.257, P < 0.001; FI: β = 0.297, 95 % CI = 0.249 to 0.346, P < 0.001), the impact remained persistent in MVMR adjusting for driving and computer use.

CONCLUSION

This study suggests that modifications in smoking, alcohol consumption, and physical activity may help prevent or manage frailty.

Causal impacts of smoking on pain conditions and the mediating pathways: a mendelian randomization study

Smoking is a risk factor for multiple diseases. We performed mendelian randomization (MR) analyses to investigate the causal association of smoking initiation on pain conditions and the potential mediating pathways. Genetic associated with smoking initiation at the genome-wide significance level were selected as instrumental variables. Genetic associations with 10 pain conditions were derived from the FinnGen and UK Biobank study. Multivariable MR analysis was conducted to explore the mediation effects of depression, insomnia and sedentary behavior. A series of sensitivity analyses were conducted to assess the stability of our research findings. Genetic liability to smoking initiation was associated with an increased risk of angina pectoris, dorsalgia, low back pain, pain in limb, pain in joint, pain in thoracic spine and sciatica in both FinnGen and UK Biobank study. These causal associations were largely mediated by major depression (2.9- 39.5%), sedentary behavior (13.0- 31.2%), insomnia (10.3- 33.1%) and combination of all three mediators (30.2- 65.3%). The effects of smoking on outcomes were partly attenuated after adjusting for depression, sedentary behavior and insomnia respectively, and the direct effect of smoking initiation on pain was diminished toward null after adjusting for combined three mediators. These results were robust to sensitivity analyses. Our findings illustrated the causal effect of smoking and a broad range of pain conditions, and major depression, sedentary behavior and insomnia mediate many of these associations.

Investigating the Genetic Association of 40 Biochemical Indicators with Parkinson's Disease

The mechanisms of Parkinson's disease (PD) are not fully understood, which hinders the development of effective therapies. Research indicates that lower levels of biochemical indicators like bilirubin, vitamin D, and cholesterol may elevate the risk of PD. However, clinical studies on abnormal levels of biochemical indicators in PD patients' circulation are inconsistent, leading to ongoing debate about their association with PD. Here, we investigate the genetic correlation between 40 biochemical indicators and PD using a bidirectional two-sample Mendelian randomization (MR) approach to uncover potential causal relationships. Data from genome-wide association studies (GWAS) were utilized, with genetic variations from specific lineages serving as instrumental variables (IVs). The methodology followed the STROBE-MR checklist and adhered to the three principal assumptions of MR. Statistical analyses employed methods including inverse variance weighting (IVW), MR-Egger, weighted median, and weighted mode. Biochemical indicators including albumin, C-reactive protein (CRP), and sex hormone-binding globulin (SHBG) showed significant associations with PD risk. Elevated levels of albumin (OR = 1.246, 95% CI 1.006-1.542, P = 0.043) and SHBG (OR = 1.239, 95% CI 1.065-1.439, P = 0.005) were linked to higher PD risk. Conversely, increased CRP levels (OR = 0.663, 95% CI 0.517-0.851; P = 0.001) could potentially lower PD risk. The robustness of the results was confirmed through various MR analysis techniques, including assessments of directional pleiotropy and heterogeneity using MR-Egger intercept and MR-PRESSO methods. This study systematically reveals, for the first time at the genetic level, the relationship between 40 biochemical indicators and PD risk. Our research verifies the role of inflammation in PD and provides new genetic evidence, further advancing the understanding of PD pathogenesis. The study shows a positive correlation between albumin and SHBG with PD risk and a negative correlation between CRP and PD risk. This study identifies for the first time that SHBG may be involved in the onset of PD and potentially worsen disease progression.

Association between biological ageing and periodontitis: Evidence from a cross-sectional survey and multi-omics Mendelian randomization analysis

AIM

To investigate the relationship and potential causality between biological ageing and periodontitis.

MATERIALS AND METHODS

We obtained the National Health and Nutrition Examination Survey (NHANES) and genome-wide association study (GWAS) summary statistics as well as single-cell sequencing data. Multivariate regression analysis based on cross-sectional data, Mendelian randomization (MR) and multi-omics integration analysis were employed to explore the causal association and potential molecular mechanisms between biological ageing and periodontitis. Additionally, two-step MR mediation analysis explored the risk factors in biological ageing-mediated periodontitis.

RESULTS

We analysed data from 3189 participants in the NHANES data and found that higher biological age was associated with increased risk of periodontitis. MR analyses revealed causal associations between biological age measures and periodontitis risk. Frailty (odds ratio [OR] = 2.08, 95% confidence interval [CI]: 1.04-4.18, p = .039) and GrimAge acceleration (OR = 1.16, 95% CI: 1.01-1.32, p = .033) were causally associated with periodontitis risk, and these results were validated in a large-scale meta-periodontitis GWAS dataset. Additionally, the risk effects of body mass index, waist circumference and lifetime smoking on periodontitis were partially mediated by frailty and GrimAge acceleration.

CONCLUSIONS

Evidence from cross-sectional survey and MR analysis suggests that biological ageing increases the risk of periodontitis. Additionally, improving the associated risk factors can help prevent both ageing and periodontitis.

Causal associations of physical activity and leisure sedentary behaviors with age at onset of Huntington's disease: A mendelian randomization study

BACKGROUND

Huntington's disease (HD) is a neurodegenerative disorder for which effective therapies are currently lacking. Studies suggest that increasing physical activity (PA) and reducing leisure sedentary behavior (LSB) mitigate the progression of HD, but their causal relationship with the age at onset (AAO) of HD remains uncertain. To investigate this, we conducted the Two-sample Mendelian Randomization (MR).

METHODS

Exposure were retrieved from the UK BioBank's (UKB) Genome-Wide Association Study (GWAS). PA included accelerometer-based average PA, vigorous PA, self-reported moderate-to-vigorous PA (MVPA), and light do-it-yourself activity. LSB included television (TV) time, computer time, and driving time. Outcome came from the GWAS of the GEM-HD Consortium. We applied several MR methods such as inverse variance weighted (IVW), MR-Egger regression, weighted median (WM) for sensitivity analysis.

RESULTS

Increases in light PA (β = 8.53 years, 95 % CI = 10.64 to 44.09, P = 0.001) and accelerometer-based vigorous PA (β = 5.18, 95 % CI = 0.92 to 9.43, P = 0.017) delayed AAO of HD, while longer TV time was associated with earlier AAO of HD (β = -2.88 years, 95 % CI = -4.99 to -0.77, P = 0.007). However, other PA and LSB phenotypes did not significantly affect AAO of HD.

CONCLUSION

The study revealed a unidirectional causality between PA, LSB and the AAO of HD. Increasing PA and reducing TV time delay HD onset. Therefore, we recommend increasing physical activity and reducing sedentary behavior to delay the occurrence of motor symptoms for premanifest HD individuals.

Causal effects of sedentary behaviours on the risk of migraine: A univariable and multivariable Mendelian randomization study

BACKGROUND

Migraine is a common and burdensome neurological disorder. The causal relationship between sedentary behaviours (SBs) and migraine remains instinct. We aimed to evaluate the roles of SBs including watching TV, using computer and driving in the risk of migraine.

METHODS

We conducted a univariable and multivariable Mendelian randomization (MR) study based on summary datasets of large genome-wide association studies. The inverse variance weighted method was utilized as the primary analytical tool. Cochran's Q, MR-Egger intercept test, MR pleiotropy residual sum and outlier and leave-one-out were conducted as sensitivity analysis. Additionally, we performed a meta-analysis to combine the causal estimates.

RESULTS

In the discovery analysis, we identified causal associations between time spent watching TV and an increased risk of migraine (p = 0.015) and migraine without aura (MO) (p = 0.002). Such causalities with increasing risk of migraine (p = 0.005), and MO (p = 0.006) were further verified using summary datasets from another study in the replication analysis. There was no significant causal association found between time spent using computer, driving and migraine or its two subtypes. The meta-analysis and multivariable MR analysis also strongly supported the causal relationships between time spent watching TV and an increased risk of migraine (p = 0.0003 and p = 0.034), as well as MO (p < 0.0001 and p = 0.0004), respectively. These findings were robust under all sensitivity analysis.

CONCLUSIONS

Our study suggested that time spent watching TV may be causally associated with an increased risk of migraine, particularly MO. Large-scale and well-designed cohort studies may be warranted for further validation.

SIGNIFICANCE STATEMENT

This study represents the first attempt to investigate whether a causal relationship exists between SBs and migraine. Utilizing MR analysis helps mitigate reverse causation bias and confounding factors commonly encountered in observational cohorts, thereby enhancing the robustness of derived causal associations. Our MR analysis revealed that time spent watching TV may serve as a potential risk factor for migraine, particularly MO.

CD4+ Effective Memory T Cell Markers GBP2 and LAG3 Are Risk Factors for PTB and COVID-19 Infection: A Study Integrating Single-Cell Expression Quantitative Trait Locus and Mendelian Randomization Analyses

Observational studies indicate that variations in peripheral blood mononuclear cell (PBMC) subsets are associated with an increased risk of pulmonary tuberculosis (PTB) and coronavirus disease 2019 (COVID-19), but causal validation is lacking. Here, we combined single-cell expression quantitative trait locus (sc-eQTL) and two-sample mendelian randomization (MR) analyses to elucidate the causal relationship between PBMC subsets and the occurrence of PTB and COVID-19 and verified by RT-qPCR. We observed an increase in the CD4+ Effective Memory T Cell (CD4+ TEM) cluster in both PTB and COVID-19 patients according to the single-cell transcriptional landscape of PBMC. Through MR analysis using an inverse variance weighted (IVW) method, we found strong evidence of positive correlations between CD4+ TEM cell markers (GBP2, TRAV1-2, and ODF2L) and PTB, and between markers (LAG3 and SLFN5) and COVID-19, especially highlighted by lead eQTL-SNPs of GBP2 (rs2256752, p = 4.76321 × 10-15) and LAG3 (rs67706382, p = 6.16× 10-16). Similar results were observed in validation sets, and no pleiotropy was detected in sensitivity analyses including weighted median (WM), MR-Egger, MR-pleiotropy residual sum and outlier, and leave-one-out analyses (all p > 0.05). We visualized the colocalization of marker-eQTLs and markers of PTB and COVID-19 genome-wide association study (GWAS) associations. Based on CellChat analyses, monocytes communicated predominantly with CD4+ TEM cells positively expressing PTB markers (GBP2, TRAV1-2, and ODF2L) and COVID-19 markers (LAG3 and SLFN5) in both PTB and COVID-19. Our data suggest a causal effect between two key CD4+ TEM cell markers (GBP2 and LAG3) and the risk for PTB and COVID-19 infection. Our findings provide novel insights into the biological mechanism for PTB and COVID-19 infection, but future single-cell studies are necessary to further enhance understanding of this find.

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.

Physical activity, sedentary behavior, and risk of sepsis: a two-sample mendelian randomization study

Objective

This investigation aimed to explore the potential causal relationship between physical activity, sedentary behavior and the risk of sepsis.

Methods

Using a two-sample Mendelian randomization approach, this study evaluated the association between physical activity (including moderate to vigorous physical activity [MVPA], vigorous physical activity [VPA], and accelerometer assessed physical activity) and sedentary behaviors (including television watching, computer use, and driving) with the risk of sepsis. This assessment was based on whole-genome association study data from the UK Biobank and the FinnGen database. Causal inferences were estimated using inverse variance-weighted, weighted median, and MR-Egger methods. Sensitivity analyses were performed using Cochran's Q test, the MR-Egger intercept test, and the leave-one-out method.

Results

The risk of sepsis was significantly inversely associated with genetically predicted MVPA (odds ratio [OR] 0.47, 95% confidence interval [CI] 0.24-0.93, P = 0.0296) and VPA alone (OR 0.19, 95% CI 0.04-0.87, P = 0.0324). Conversely, prolonged driving time showed a significant positive association with the risk of sepsis (OR 3.99, 95% CI 1.40-11.40, P = 0.0097).

Conclusion

This study provides preliminary evidence of a causal relationship between MVPA and VPA and a reduced risk of sepsis, while prolonged sedentary behaviors such as driving are positively associated with an increased risk of sepsis. These findings provided essential scientific evidence for the development of effective sepsis prevention strategies.

Leisure television watching exerts a causal effect on gastroesophageal reflux disease: evidence from a two-step mendelian randomization study

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%).

CONCLUSION

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.

Engineering artificial cross-species promoters with different transcriptional strengths

As a fundamental tool in synthetic biology, promoters are pivotal in regulating gene expression, enabling precise genetic control and spurring innovation across diverse biotechnological applications. However, most advances in engineered genetic systems rely on host-specific regulation of the genetic portion. With the burgeoning diversity of synthetic biology chassis cells, there emerges a pressing necessity to broaden the universal promoter toolkit spectrum, ensuring adaptability across various microbial chassis cells for enhanced applicability and customization in the evolving landscape of synthetic biology. In this study, we analyzed and validated the primary structures of natural endogenous promoters from Escherichia coli, Bacillus subtilis, Corynebacterium glutamicum, Saccharomyces cerevisiae, and Pichia pastoris, and through strategic integration and rational modification of promoter motifs, we developed a series of cross-species promoters (Psh) with transcriptional activity in five strains (prokaryotic and eukaryotic). This series of cross species promoters can significantly expand the synthetic biology promoter toolkit while providing a foundation and inspiration for standardized development of universal components The combinatorial use of key elements from prokaryotic and eukaryotic promoters presented in this study represents a novel strategy that may offer new insights and methods for future advancements in promoter engineering.

Association between primary biliary cholangitis with diabetes and cardiovascular diseases: A bidirectional multivariable Mendelian randomization study

BACKGROUND AND AIMS

Primary biliary cholangitis (PBC) is an autoimmune disease often accompanied by multisystem damage. This study aimed to explore the causal association between genetically predicted PBC and diabetes, as well as multiple cardiovascular diseases (CVDs).

METHODS

Genome-wide association studies (GWAS) summary data of PBC in 24,510 individuals of European ancestry from the European Association for the Study of the Liver was used to identify genetically predicted PBC. We conducted 2-sample single-variable Mendelian randomization (SVMR) and multivariable Mendelian randomization (MVMR) to estimate the impacts of PBC on diabetes (N = 17,685 to 318,014) and 20 CVDs from the genetic consortium (N = 171,875 to 1,030,836).

RESULTS

SVMR provided evidence that genetically predicted PBC is associated with an increased risk of type 1 diabetes (T1D), type 2 diabetes (T2D), myocardial infarction (MI), heart failure (HF), hypertension, atrial fibrillation (AF), stroke, ischemic stroke, and small-vessel ischemic stroke. Additionally, there was no evidence of a causal association between PBC and coronary atherosclerosis. In the MVMR analysis, PBC maintained independent effects on T1D, HF, MI, and small-vessel ischemic stroke in most models.

CONCLUSION

Our findings revealed the causal effects of PBC on diabetes and 7 CVDs, and no causal relationship was detected between PBC and coronary atherosclerosis.

Sedentary behavior from television watching elevates GlycA levels: A bidirectional Mendelian randomization study

BACKGROUND

Current evidence linking sedentary behavior (SB), physical activity (PA), and inflammation raises questions about their causal relationships, prompting concerns about potential residual confounding or reverse causation.

METHODS

A bidirectional Mendelian randomization (MR) analysis was conducted. SB data (n = 408,815) from "computer use," "television watching," and "driving" were included. The PA data encompassed nine types of PA (n = 460,376) over the last four weeks and included data on the frequency of vigorous PA (n = 440,512) and moderate PA (n = 440,266) for over 10 min. Additionally, three genome-wide association study datasets (n = 64,949) on light, moderate, and vigorous exercise were included to minimize potential bias from changes in exercise intensity. Inflammation data included levels of C-reactive protein (CRP) (n = 575,531), glycoprotein acetyl (GlycA) (n = 115,082), interleukin (IL)-8, IL-6, IL-6 receptor (IL-6R), and soluble IL-6R (sIL-6R) (n = 35,278). All datasets represented participants of European ancestry.

RESULTS

Television watching as an SB showed significant positive causal effects on GlycA and CRP (inverse variance weighted (IVW), odds ratios (OR): 1.34, 95% confidence intervals (CI): 1.25-1.44, p = 3.570 × 10-17; IVW, OR: 1.21, 95% CI: 1.16-1.26, p = 1.500 × 10-19, respectively), with more robust evidence for GlycA. In the direction from inflammation to PA, a negative causal relationship between CRP and"number of days/week of moderate PA 10+ minutes"was observed (IVW, OR: 0.92, 95% CI: 0.89-0.96, p = 3.260 × 10-5). Sensitivity analyses were used to verify the robustness and reliability of the results. However, other initially observed associations ceased to be significant after controlling for obesity-related confounders.

CONCLUSION

Our MR analysis suggested a potential causal relationship between television watching and chronic low-grade inflammation, with more substantial evidence for GlycA. Additionally, different types of SB may have varying effects on inflammation. Obesity-related traits could partly or entirely influence the relationship between SB, PA, and inflammatory markers. Furthermore, Our findings indicate that SB is an independent risk factor for inflammation, separate from PA, and highlight the different mechanisms by which SB and PA affect disease.

Effects of walking on epigenetic age acceleration: a Mendelian randomization study

INTRODUCTION

Walking stands as the most prevalent physical activity in the daily lives of individuals and is closely associated with physical functioning and the aging process. Nonetheless, the precise cause-and-effect connection between walking and aging remains unexplored. The epigenetic clock emerges as the most promising biological indicator of aging, capable of mirroring the biological age of the human body and facilitating an investigation into the association between walking and aging. Our primary objective is to investigate the causal impact of walking with epigenetic age acceleration (EAA).

METHODS

We conducted a two-sample two-way Mendelian randomization (MR) study to investigate the causal relationship between walking and EAA. Walking and Leisure sedentary behavior data were sourced from UK Biobank, while EAA data were gathered from a total of 28 cohorts. The MR analysis was carried out using several methods, including the inverse variance weighted (IVW), weighted median, MR-Egger, and robust adjusted profile score (RAPS). To ensure the robustness of our findings, we conducted sensitivity analyses, which involved the MR-Egger intercept test, Cochran's Q test, and MR-PRESSO, to account for and mitigate potential pleiotropy.

RESULTS

The IVW MR results indicate a significant impact of usual walking pace on GrimAge (BETA = - 1.84, 95% CI (- 2.94, - 0.75)), PhenoAge (BETA = - 1.57, 95% CI (- 3.05, - 0.08)), Horvath (BETA = - 1.09 (- 2.14, - 0.04)), and Hannum (BETA = - 1.63, 95% CI (- 2.70, - 0.56)). Usual walking pace is significantly associated with a delay in epigenetic aging acceleration (EAA) (P < 0.05). Moreover, the direction of effect predicted by the gene remained consistent across RAPS outcomes and sensitivity MR analyses. There is a lack of robust causal relationships between other walking conditions, such as walking duration and walking frequency, on EAA (P > 0.05).

CONCLUSION

Our evidence demonstrates that a higher usual walking pace is associated with a deceleration of the acceleration of all four classical epigenetic clocks acceleration.

MRBEE: A bias-corrected multivariable Mendelian randomization method

Mendelian randomization (MR) is an instrumental variable approach used to infer causal relationships between exposures and outcomes, which is becoming increasingly popular because of its ability to handle summary statistics from genome-wide association studies. However, existing MR approaches often suffer the bias from weak instrumental variables, horizontal pleiotropy and sample overlap. We introduce MRBEE (MR using bias-corrected estimating equation), a multivariable MR method capable of simultaneously removing weak instrument and sample overlap bias and identifying horizontal pleiotropy. Our extensive simulations and real data analyses reveal that MRBEE provides nearly unbiased estimates of causal effects, well-controlled type I error rates and higher power than comparably robust methods and is computationally efficient. Our real data analyses result in consistent causal effect estimates and offer valuable guidance for conducting multivariable MR studies, elucidating the roles of pleiotropy, and identifying total 42 horizontal pleiotropic loci missed previously that are associated with myopia, schizophrenia, and coronary artery disease.

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.

Causal relationships of physical activity and leisure sedentary behaviors with COPD: A Mendelian randomization study

BACKGROUND

Chronic diseases such as chronic obstructive pulmonary disease (COPD) have been linked to low levels of physical activity (PA) and higher frequency of leisure sedentary behavior (LSB). The main causes of COPD include respiratory and peripheral muscle dysfunction, low levels of PA, and LSB which are associated with a higher risk of developing COPD. The attribution relationship between PA or LSB and COPD risk or COPD respiratory insufficiency is unclear. To explore this further, we conducted a Mendelian randomization (MR) study using a genotype-simulated randomized trial group to systematically evaluate the causal relationships of PA/LSB on COPD risk and respiratory insufficiency.

METHODS

The exposure data were obtained from large-scale genome-wide association studies (GWAS), including the PA dataset (N = 729,373) and LSB dataset (N = 1,109,337). The outcome data were derived from the Finn-Gen COPD dataset (N = 381,392). The causal effects were estimated with IVW1, MR-Egger, and WM2. Sensitivity analysis was conducted using Cochran's Q test, MR-Egger intercept test, MR-PRESSO3, leave-one-out analysis, and funnel plot to estimate the robustness of our findings.

RESULTS

Genetically predicted leisure television (TV) watching significantly increased the risk of COPD (OR = 2.4895, 95 % CI: 1.85259 to 3.34536; P = 1.44 × 10-9) and COPD respiratory insufficiency (OR = 2.55, 95 % CI: 1.53 to 4.27; P = 3.54 × 10-4). No casual effect of other PA or LSB phenotypes on COPD risk or respiratory insufficiency was observed.

CONCLUSION

Our study provides evidence that TV watching may increase the risk of COPD and its related respiratory insufficiency. These findings emphasized the importance of promoting regular physical exercise and reducing leisure sedentary behavior to prevent COPD.

Socioeconomic status, individual behaviors and risk for Lymphomas: a Mendelian randomization study

Background: The association of socioeconomic status and individual behavior (SES/IB) with human health is receiving increasing attention. However, the causal effects between SES/IB and lymphomas remain unclear. Methods: A two-sample Mendelian randomization (MR) study was used to assess the causal effects of 25 SES/IB traits (dietary habits, physical activity, smoking/drinking behaviors, sleeping behaviors, leisure sedentary behaviors, risky behaviors, and reproductive behaviors) on six distinct types of lymphomas, including Hodgkin lymphoma (HL), follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), mature T/NK-cell lymphomas, marginal zone B-cell lymphoma (MZL), and mantle cell lymphoma (MCL). The inverse variance weighted (IVW) method was the primary approach used for the MR analysis. A series of sensitivity analyses were also conducted to ensure the robustness of the findings. Results: Two-sample MR revealed six SES/IB traits causally associated with lymphomas, including relative fat intake, drive time, television watching time, computer use time, vigorous physical activity, and number of children ever born. After false discovery rate (FDR) correction, the causal associations between longer television watching time and DLBCL (OR: 4.048, 95% CI: 1.688 to 9.708, P fdr=0.009), and the number of children ever born with both FL (OR: 0.008, 95% CI: 1.412E-04 to 0.484, P fdr=0.021) and DLBCL (OR: 0.001, 95% CI:1.587E-05 to 0.081, P fdr=0.002) were identified. Conclusions: These findings suggest that certain lifestyle and behavioral factors have a measurable impact on specific lymphoma types.

Could the association between ozone and arterial stiffness be modified by fish oil supplementation?

BACKGROUND

Arterial stiffness (AS) is an important predicting factor for cardiovascular disease. However, no epidemiological studies have ever explored the mediating role of biomarkers in the association between ozone and AS, nor weather fish oil modified such association.

METHODS

Study participants were drawn from the UK biobank, and a total of 95,699 middle-aged and older adults were included in this study. Ozone was obtained from Community Multiscale Air Quality (CMAQ) model matched to residential addresses, fish oil from self-reported intake, and arterial stiffness was based on device measurements. First, we applied a double robust approach to explore the association between ozone or fish oil intake and arterial stiffness, adjusting for potential confounders at the individual and regional levels. Then, how triglycerides, apolipoprotein B (Apo B)/apolipoprotein A (ApoA) and non-high-density lipoprotein cholesterol (Non-HDL-C) mediate the relationship between ozone and AS. Last, the modifying role of fish oil was further explored by stratified analysis.

RESULTS

The mean age of participants was 55 years; annual average ozone exposure was associated with ASI (beta:0.189 [95%CI: 0.146 to 0.233], P < 0.001), and compared to participants who did not consume fish oil, fish oil users had a lower ASI (beta: 0.061 [95%CI: -0.111 to -0.010], P = 0.016). The relationship between ozone exposure and AS was mediated by triglycerides, ApoB/ApoA, and Non-HDL-C with mediation proportions ranging from 10.90% to 18.30%. Stratified analysis showed lower estimates on the ozone-AS relationship in fish oil users (P = 0.011).

CONCLUSION

Ozone exposure was associated with higher levels of arterial stiffness, in contrast to fish oil consumption, which showed a protective association. The association between ozone exposure and arterial stiffness was partially mediated by some biomarkers. In the general population, fish oil consumption might provide protection against ozone-related AS.

Modifiable Lifestyle, Sedentary Behaviors and the Risk of Frailty: A Univariate and Multivariate Mendelian Randomization Study

This research conducted a two-sample univariate and multivariate Mendelian Randomization (MR) analysis to explore the causal link between different types of leisure sedentary behavior (LSB) and frailty. Independent instrumental variables significantly associated with sedentary behaviors (p < 5 × 10-8) are obtained from a genome-wide association study (GWAS) of 422,218 individuals, and Frailty Index (FI) are derived from the latest GWAS dataset of 175,226 individuals. MR analysis is conducted using inverse variance weighting, MR-Egger, weighted median, simple mode, and weighted mode, supplemented by MRAPSS. Univariate MR revealed that sedentary behaviors such as watching television increased the risk of frailty (OR, 1.271; 95% CI: 1.202-1.345; p = 6.952 × 10-17), as sedentary driving behaviors are done (OR, 1.436; 95% CI: 1.026-2.011; p = 0.035). Further validation through APSS, taking into account cryptic relatedness, stratification, and sample overlap, maintained the association between television viewing and increased frailty risk (OR, 1.394; 95% CI: 1.266-1.534; p = 1.143 × 10-11), while the association with driving dissipated. In multivariate inverse variance weighted (IVW) analysis, after adjusting for C-reactive protein (CRP) levels, television Sedentary behavior (SB) inversely affected frailty (OR, 0.782; 95% CI: 0.724-0.845; p = 4.820 × 10-10). This study indicates that televisio SB significantly increases the risk of frailty, suggesting potential biological heterogeneity behind specific sedentary activities. This process may interact with inflammation, influencing the development of frailty.

Assessing the causal role of physical activity and leisure sedentary behaviours with chronic obstructive pulmonary disease: a Mendelian randomisation study

BACKGROUND

Observational studies show that patients with chronic obstructive pulmonary disease (COPD) tend to be sedentary during leisure time. Physical activity (PA) may reduce the risk of COPD, but the causal relationship is unclear. We used a Mendelian randomisation (MR) method to elucidate the association of leisure sedentary behaviours (LSB) and PA with lung function and COPD.

METHODS

Data on LSB (n=422 218), PA (n=608 595), COPD (n=299 929) and lung function (n=79 055) were obtained from the large-scale genome-wide association study. Causal inference used inverse variance-weighted, MR-Egger and weighted median. Sensitivity analysis was performed to assess heterogeneity and pleiotropy, and radial MR was used to distinguish outliers. The primary outcome was analysed by multifactorial MR adjusted for daily smoking.

RESULTS

The inverse variance weighted analysis indicated that increased moderate-to-vigorous PA (MVPA) is associated with higher levels of forced vital capacity (FVC) (beta=0.27, 95% CI 0.12 to 0.42; p=3.51×10-4). For each increment of 2.8 hours in television watching, the odds of COPD were 2.25 times greater (OR=2.25; 95% CI 1.84 to 2.75; p=2.38×10-15). For early-onset COPD, the odds were 2.11 times greater (OR=2.11; 95% CI 1.56 to 2.85; p=1.06×10-6), and for late-onset COPD, the odds were 2.16 times greater (OR=2.16; 95% CI 1.64 to 2.84; p=3.12×10-8). Similarly, the odds of hospitalisation for COPD were 2.02 times greater with increased television watching (OR=2.02; 95% CI 1.59 to 2.55; p=4.68×10-9). Television watching was associated with lower FVC (beta=-0.19, 95% CI -0.28 to -0.10; p=1.54×10-5) and forced expiratory volume in the 1 s (FEV1) (beta=-0.16, 95% CI -0.25 to -0.08; p=1.21×10-4) levels. The results remained significant after adjustment for smoking.

CONCLUSIONS

Our study suggests a potential association with LSB, particularly television watching, is associated with higher odds of COPD and lower indices of lung function as measured continuously, including FEV1 and FVC. Conversely, an increase in MVPA is associated with higher indices of lung function, particularly reflected in increased FVC levels.

Association between leisure sedentary behaviors and hypertension risk: A prospective cohort study and two-sample Mendelian randomization analysis in Europeans

OBJECTIVE

This study aimed to investigate the potential causal relationship between domain-specific sedentary behaviors (including television watching, computer use, and driving) and hypertension risk in European populations.

METHODS

Initially, we conducted a multivariable Cox regression analysis to evaluate the associations between domain-specific sedentary behaviors and the risk of developing hypertension using data from 261,829 hypertension-free participants in the UK Biobank. To validate the findings of observational analysis, we employed two-sample univariable mendelian randomization (UVMR) analysis utilizing summary statistics from genome-wide association study conducted on European populations. We then performed multivariable mendelian randomization (MVMR) analysis to account for the influence of the risk factors for hypertension.

RESULTS

In this prospective observational analysis, individuals who spent >3 h per day watching television had significantly higher risk of developing hypertension (HR = 1.24, 95% CI: 1.20-1.29, P < 0.001) compared to those who watched television for 0-1 h per day. The mendelian randomization analysis provided consistent evidence for a causal relationship between prolonged television watching time and hypertension risk (OR = 1.45, 95% CI: 1.25-1.69, P < 0.001; all PMVMR < 0.05) in both UVMR and MVMR results. No significant associations were found between computer use, driving behaviors and the risk of hypertension in either the observational or UVMR/MVMR analyses.

CONCLUSIONS

These findings provide evidence for a causal effect specifically linking higher television watching time to an increased risk of hypertension and indicate the potential effectiveness of reducing television viewing time as a preventive measure to mitigate the risk of hypertension.

Potential causal association between leisure sedentary behaviors and osteoporosis: A two-sample Mendelian randomization analysis

Previous observational studies have observed a correlation between sedentary behavior and osteoporosis. However, conclusions from these studies have been contradictory. To explore the potential causal relationship between sedentary behavior and osteoporosis, we conducted a Mendelian randomization analysis. A two-sample Mendelian randomization was adopted to explore the causal relationship of leisure sedentary behavior with osteoporosis. We employed 5 methods to estimate the causal associations between leisure sedentary behavior and osteoporosis. Univariable Mendelian randomization results provided evidence for the causal relationship of the time spent on computer-use with the bone mineral density estimated by heel quantitative ultrasound (eBMD) (inverse variance weighted [IVW]: β (95% confidence interval [CI]) - 0.150 (-0.270 to -0.031), P = .013; weighted median: β (95%CI) - 0.195 (-0.336 to -0.055), P = .006). Similar associations were observed in the driving forearm bone mineral density (FABMD) (IVW: β (95%CI) - 0.933 (-1.860 to -0.007), P = .048) and driving lumbar spine bone mineral density (IVW: β (95%CI) - 0.649 (-1.175 to -0.124), P = .015). However, we did not find a significant causal relationship between the time spent on watching TV and bone mineral density. Research showed that there was a causal relationship between the time spent on computer use and driving time and eBMD, FABMD, and lumbar spine bone mineral density.

Sedentary behavior, physical activity, sleep duration and obesity risk: Mendelian randomization study

BACKGROUND

Observational studies have suggested associations between sedentary behaviors (SB), physical activity (PA), sleep duration (SD), and obesity, but the causal relationships remain unclear.

METHODS

We used Mendelian randomization (MR) with genetic variation as instrumental variables (IVs) to assess the causality between SB/PA/SD and obesity. Genetic variants associated with SB/PA/SD were obtained from Genome-wide association study (GWAS), and obesity data came from FinnGen. The primary MR analysis used the instrumental variable weighted (IVW) method, with sensitivity tests including Cochran Q, MR-Egger intercepts, and MR-Radial. Expression Quantitative Trait Loci (eQTL) analysis was applied to identify significant genetic associations and biological pathways in obesity-related tissues.

RESULTS

The MR analysis revealed causal relationships between four SB-related lifestyle patterns and obesity. Specifically, increased genetic liability to television watching (IVW MR Odds ratio [OR] = 1.55, [95% CI]:[1.27, 1.90], p = 1.67×10-5), computer use ([OR] = 1.52, [95% CI]:[1.08, 2.13], p = 1.61×10-2), leisure screen time (LST) ([OR] = 1.62, [95% CI] = [1.43, 1.84], p = 6.49×10-14, and driving (MR [OR] = 2.79, [95% CI]:[1.25, 6.21], p = 1.23×10-2) was found to increase the risk of obesity. Our findings indicate that no causal relationships were observed between SB at work, sedentary commuting, PA, SD, and obesity. The eQTL analysis revealed strong associations between specific genes (RPS26, TTC12, CCDC92, NICN1) and SNPs (rs10876864, rs2734849, rs4765541, rs7615206) in both subcutaneous and visceral adipose tissues, which are associated with these SBs. Enrichment analysis further revealed that these genes are involved in crucial biological pathways, including cortisol synthesis, thyroid hormone synthesis, and insulin secretion.

CONCLUSIONS

Our findings support a causal relationship between four specific SBs (LST, television watching, computer use, driving) and obesity. These results provide valuable insights into potential interventions to address obesity effectively, supported by genetic associations in the eQTL and enrichment analysis. Further research and public health initiatives focusing on reducing specific SBs may be warranted.

Effects of common lifestyle factors on obstructive sleep apnea: precautions in daily life based on causal inferences

Background

This study aimed to evaluate the causal impact of common modifiable lifestyles on obstructive sleep apnea (OSA), which is beneficial for recommendations to prevent and manage OSA.

Method

Published genome-wide association study (GWAS) summary statistics were used to perform two-sample Mendelian randomization (MR). Variants associated with each exposure of smoking, drinking, and leisure sedentary behaviors at the genetic level were used as instrumental variables (IVs). Then, inverse-variance weighting (IVW) was considered the primary result for causality. Moreover, several complimented approaches were also included to verify the observed associations. MR-PRESSO and MR-Egger intercept were applied to test the horizontal pleiotropy. To assess heterogeneity, Cochran's Q test by IVW and MR-Egger were applied.

Results

Regular smoking history increased OSA risk in all applied approaches [OR (95% CI)IVW = 1.28 (1.12, 1.45), p = 1.853 × 10-4], while the causality of lifetime smoking index [OR (95% CI)IVW = 1.39 (1.00, 1.91), p = 0.048], alcohol intake frequency [outliers removed OR (95% CI)IVW = 1.26 (1.08, 1.45), p = 0.002], and coffee intake behavior [OR (95% CI)IVW = 1.66 (1.03, 2.68), p = 0.039] on OSA risk were not always consistent in other approaches. In addition, no robust causal associations were observed for the effect of sedentary leisure behaviors on OSA risk. In sensitivity analysis, we observed no sign of horizontal pleiotropy or heterogeneity.

Conclusion

Ever regularly smoking has a robust causal role in increasing OSA risk, which should be discouraged as precautions from developing OSA.

Potential causal associations between leisure sedentary behaviors, physical activity, sleep traits, and myopia: a Mendelian randomization study

BACKGROUND

Myopia is the most prevalent refractive error and a growing global health concern that significantly affects visual function. Researchers have recently emphasized considerably on the influence of lifestyle on myopia incidence and development. This study investigates the relationship between leisure sedentary behaviors (LSB)/physical activity (PA)/sleep traits and myopia.

METHODS

LSB, PA, and sleep trait-associated genetic variants were used as instrument variables in a Mendelian randomization (MR) study to examine their causal effects on myopia. Summary genome-wide association studies (GWASs) statistical data for LSB and PA were obtained from UK Biobank, and the data of sleep traits was obtained from UK Biobank, UK Biobank and 23andMe, and FinnGen. We used summary statistics data for myopia from MRC IEU. The MR analyses was performed using the inverse variance-weighted (IVW), MR-Egger, weighted median, and MR Pleiotropy RESidual Sum and Outlier methods.

RESULTS

Computer use was genetically predicted to increase the myopia risk [IVW odds ratio (OR) = 1.057; 95% confidence interval (CI), 1.038-1.078; P = 7.04 × 10- 9]. The self-reported moderate-to-vigorous physical activity (MVPA) (IVW OR = 0.962; 95% CI, 0.932-0.993; P = 1.57 × 10- 2) and television watching (IVW OR = 0.973; 95% CI, 0.961-0.985, P = 1.93 × 10- 5) were significantly associated with a lower myopia risk. However, genetically predicted sleep traits or accelerometer-measured physical activity had no significant associations with myopia.

CONCLUSION

Our results indicated that computer use is a risk factor for myopia, whereas television watching and MVPA may protect against myopia. These findings shed new light on possible strategies for reducing the prevalence of myopia.

Causal links between sedentary behavior, physical activity, and psychiatric disorders: a Mendelian randomization study

BACKGROUND

Studies suggest a correlation between excessive sedentary behavior, insufficient physical activity, and an elevated likelihood of experiencing psychiatric disorder. Nonetheless, the precise influence of sedentary behavior and physical activity on psychiatric disorder remains uncertain. Hence, the objective of this research was to investigate the possible causal relationship between sedentary behavior, physical activity, and the susceptibility to psychiatric disorder (depression, schizophrenia and bipolar disorder), utilizing a two-sample Mendelian randomization (MR) approach.

METHODS

Potential genetic instruments related to sedentary leisure behaviors were identified from the UK Biobank database, specifically a summary-level genome-wide association study (GWAS) involving 422,218 individuals of European descent. The UK Biobank database also provided the GWAS data for physical activity. Primary analysis was performed using inverse variance weighting (IVW) to assess the causal relationship between sedentary behavior, physical activity, and the risk of psychiatric disorder (depression, schizophrenia and bipolar disorder). Sensitivity analysis was conducted using Cochran's Q test, the MR-Egger intercept test, the MR-pleiotropy RESidual sum and outlier test, leave-one-out analysis, and funnel plot analysis.

RESULTS

According to the IVW analysis, there was a significant association between genetically predicted leisure television watching and an increased risk of depression (odds ratio [OR] = 1.027, 95% confidence interval [CI]: 1.001-1.053; P = 0.04). The IVW analysis also indicated that there was a decreased risk of depression associated with fraction accelerations of > 425 milligravities, as measured by accelerometers (OR = 0.951, 95%CI: 0.914-0.989; P = 0.013). The other MR methods obtained consistent but non-significant results in the same direction. However, there was no evidence of a causal association between genetic liability for moderate-to-vigorous physical activity, accelerometer-assessed physical activity, computer use, or driving and the risk of depression. Furthermore, IVW analysis has also found that driving has a slight effect in reducing the risk of schizophrenia (OR = 0.092, 95%CI: 0.010-0.827; P = 0.033), while leisure television viewing has a significant protective effect against the onset of bipolar disorder (OR = 0.719, 95%CI: 0.567-0.912; P = 0.006).

CONCLUSION

The study provides compelling evidence of a link between depression, bipolar disorder, and excessive TV watching. Furthermore, it suggests that higher accelerometer-assessed fraction accelerations of > 425 milligravities can serve as a genetic protective factor against depression. To mitigate the risk of developing depression, it is advisable to reduce sedentary activities, particularly television watching, and prioritize engaging in vigorous physical exercise.

Physical Activity, Sedentary Behavior, and Pancreatic Cancer Risk: A Mendelian Randomization Study

Pancreatic cancer is currently the seventh leading cause of cancer death worldwide. Understanding whether modifiable factors increase or decrease the risk of this disease is central to facilitating primary prevention. Several epidemiological studies have described the benefits of physical activity, and the risks associated with sedentary behavior, in relation to cancer. This study aimed to assess evidence of causal effects of physical activity and sedentary behavior on pancreatic cancer risk. We conducted a two-sample Mendelian randomization study using publicly available data for genetic variants associated with physical activity and sedentary behavior traits and genetic data from the Pancreatic Cancer Cohort Consortium (PanScan), the Pancreatic Cancer Case-Control Consortium (PanC4), and the FinnGen study for a total of 10 018 pancreatic cancer cases and 266 638 controls. We also investigated the role of body mass index (BMI) as a possible mediator between physical activity and sedentary traits and risk of developing pancreatic cancer. We found evidence of a causal association between genetically determined hours spent watching television (hours per day) and increased risk of pancreatic cancer for each hour increment (PanScan-PanC4 odds ratio = 1.52, 95% confidence interval 1.17-1.98, P = .002). Additionally, mediation analysis showed that genetically determined television-watching time was strongly associated with BMI, and the estimated proportion of the effect of television-watching time on pancreatic cancer risk mediated by BMI was 54%. This study reports the first Mendelian randomization-based evidence of a causal association between a measure of sedentary behavior (television-watching time) and risk of pancreatic cancer and that this is strongly mediated by BMI. Summary: Pancreatic cancer is a deadly disease that is predicted to become the second leading cause of cancer-related deaths by 2030. Physical activity and sedentary behaviors have been linked to cancer risk and survival. However, there is limited research on their correlation with pancreatic cancer. To investigate this, we used a Mendelian randomization approach to examine the genetic predisposition to physical activity and sedentariness and their relation to pancreatic cancer risk, while excluding external confounders. Our findings revealed a causal link between the time spent watching television and an increased risk of pancreatic cancer. Additionally, we determined that over half of the effect of watching television on pancreatic risk is mediated by the individual's BMI.

Causal associations between leisure sedentary behaviors and sleep status with frailty: insight from Mendelian randomization study

BACKGROUND

Observational studies have suggested that sedentary behaviors and sleep status are associated with frailty. However, it remains unclear whether these associations are causal.

METHODS

Using summary statistics from genome-wide association studies, we evaluated the causal effect of modifiable risk factors, including leisure sedentary behaviors and sleep status on the frailty index (FI) using two-sample univariable and multivariable Mendelian randomization (MR) analyses. Genetic correlations were tested between the correlated traits.

RESULTS

We identified potential causal associations between the time spent watching television (β = 0.26, 95% confidence interval [CI]: 0.21-0.31, P = 3.98e-25), sleep duration (β = -0.18, 95%CI: -0.26, -0.10; P = 6.04e-06), and daytime napping (β = 0.29, 95%CI: 0.18-0.41, P = 2.68e-07) and the FI based on the inverse-variance-weighted method. The estimates were consistent across robust and multivariate MR analyses. Linkage disequilibrium score regression detected a genetic correlation between the time spent watching television (Rg = 0.43, P = 6.46e-48), sleep duration (Rg = -0.20, P = 5.29e-10), and daytime napping (Rg = 0.25, P = 3.34e-21) and the FI.

CONCLUSIONS

Genetic predispositions to time spent watching television and daytime napping were positively associated with the FI, while sleep duration was negatively associated with the FI. Our findings offer key insights into factors influencing biological aging and suggest areas for interventions to promote healthy aging and slow down the aging process.

Smoking and BMI mediate the causal effect of education on lower back pain: observational and Mendelian randomization analyses

Objective

Low back pain (LBP) has been associated with education in previous observational studies, but the causality remains unclear. This study aims to assess the impact of education on LBP and to explore mediation by multiple lifestyle factors.

Design

Univariable Mendelian randomization (MR) was performed to examine the overall effect of education on LBP. Subsequently, multivariable MR was conducted to assess both the direct effect of education on LBP and the influence of potential mediators. Indirect effects were estimated using either the coefficient product method or the difference method, and the proportion of mediation was calculated by dividing the indirect effect by the total effect. The observational study utilized data from the NHANES database collected between 1999 and 2004, and included 15,580 participants aged 20 years and above.

Results

Increasing education by 4.2 years leads to a 48% reduction in the risk of LBP (OR=0.52; 95% CI: 0.46 to 0.59). Compared to individuals with less than a high school education, those with education beyond high school have a 28% lower risk of LBP (OR=0.72; 95% CI: 0.63 to 0.83). In the MR study, smoking accounts for 12.8% (95% CI: 1.04% to 20.8%) of the total effect, while BMI accounts for 5.9% (95% CI: 2.99% to 8.55%). The combined mediation effect of smoking and BMI is 27.6% (95% CI: 23.99% to 32.7%). In the NHANES study, only smoking exhibits a mediating effect, accounting for 34.3% (95% CI: 21.07% to 41.65%) of the effect, while BMI does not demonstrate a mediating role.

Conclusions

Higher levels of education provide a protective effect against the risk of LBP. Additionally, implementing interventions to reduce smoking and promote weight loss among individuals with lower levels of education can also decrease this risk.

Body composition, lifestyle, and depression: a prospective study in the UK biobank

BACKGROUND

Obesity has been related to depression and adhering healthy lifestyle was beneficial to lower the risk of depression; however, little is known about the relationship between body composition and fat distribution with depression risk and the influence of body composition and fat distribution on the association of lifestyle and depression. Therefore, we aimed to investigate whether body composition and fat distribution were associated with the adverse events of depression and the relationship between lifestyle and depression.

METHODS

We included 330,131 participants without depression at baseline in the UK Biobank (mean age, 56.9 years; 53.83% females). The assessment of depression was sourced from health outcomes across self-report, primary care, hospital inpatient data, and death data. Body composition was determined by bioelectrical impedance. Seven lifestyles (no current smoking, moderate alcohol consumption, regular physical activity, healthy diet, less sedentary behavior, healthy sleep pattern, and appropriate social connection) were used to generate a lifestyle score.

RESULTS

During a median of 11.7 years of follow-up, 7576 incident depression occurred. All the body composition measures were positively associated with depression risk, with the Hazard ratios (HR) for the uppermost tertile (T3) versus the lowest tertile (T1) ranging from 1.26 (95% CI: 1.15-1.39) for trunk fat-free mass (TFFM) to 1.78 (1.62-1.97) for leg fat percentage (LFP). In addition, we found significant interactions between fat mass-related indices, especially leg fat mass (LFM) (p = 1.65 × 10-9), and lifestyle score on the risk of depression, for which the beneficial associations of a healthy lifestyle with the risk of depression were more evident among participants with low body fat measurement.

CONCLUSIONS

High levels of body composition measures were associated with an increased depression risk. Adverse body composition measures may weaken the link between a healthy lifestyle and a reduced risk of depression.

Causal association of leisure sedentary behavior and cervical spondylosis, sciatica, intervertebral disk disorders, and low back pain: a Mendelian randomization study

Background

Some studies suggest sedentary behavior is a risk factor for musculoskeletal disorders. This study aimed to investigate the potential causal association between leisure sedentary behavior (LSB) (including television (TV) viewing, computer use, and driving) and the incidence of sciatica, intervertebral disk degeneration (IVDD), low back pain (LBP), and cervical spondylosis (CS).

Methods

We obtained the data of LSB, CS, IVDD, LBP, sciatica and proposed mediators from the gene-wide association studies (GWAS). The causal effects were examined by Inverse Variance Weighted (IVW) test, MR-Egger, weighted median, weighted mode and simple mode. And sensitivity analysis was performed using MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO) and MR-Egger intercept test. Multivariable MR (MVMR) was conducted to investigate the independent factor of other LSB; while two-step MR analysis was used to explore the potential mediators including Body mass index (BMI), smoking initiation, type 2 diabetes mellitus (T2DM), major depressive disorder (MDD), schizophrenia, bipolar disorder between the causal association of LSB and these diseases based on previous studies.

Results

Genetically associated TV viewing was positively associated with the risk of CS (OR = 1.61, 95%CI = 1.25 to 2.07, p = 0.002), IVDD (OR = 2.10, 95%CI = 1.77 to 2.48, p = 3.79 × 10-18), LBP (OR = 1.84, 95%CI = 1.53 to 2.21, p = 1.04 × 10-10) and sciatica (OR = 1.82, 95% CI = 1.45 to 2.27, p = 1.42 × 10-7). While computer use was associated with a reduced risk of IVDD (OR = 0.66, 95%CI = 0.55 to 0.79, p = 8.06 × 10-6), LBP (OR = 0.49, 95%CI = 0.40 to 0.59, p = 2.68 × 10-13) and sciatica (OR = 0.58, 95%CI = 0.46 to 0.75, p = 1.98 × 10-5). Sensitivity analysis validated the robustness of MR outcomes. MVMR analysis showed that the causal effect of TV viewing on IVDD (OR = 1.59, 95%CI = 1.13 to 2.25, p = 0.008), LBP (OR = 2.15, 95%CI = 1.50 to 3.08, p = 3.38 × 10-5), and sciatica (OR = 1.61, 95%CI = 1.03 to 2.52, p = 0.037) was independent of other LSB. Furthermore, two-step MR analysis indicated that BMI, smoking initiation, T2DM may mediate the causal effect of TV viewing on these diseases.

Conclusion

This study provides empirical evidence supporting a positive causal association between TV viewing and sciatica, IVDD and LBP, which were potentially mediated by BMI, smoking initiation and T2DM.