Causal relationship between physical activity, leisure sedentary behaviors and COVID-19 risk: a Mendelian randomization study

Exploring the causal effects of depression and antidepressants on COVID-19

BACKGROUND

While existing studies have suggested an increased risk of COVID-19 in patients with depression, the causal impact of MDD on the severity of COVID-19 remains to be validated. Additionally, the potential impact of antidepressant medication on the risk of COVID-19 is not known.

METHODS

In our study, we applied a Mendelian Randomization (MR) method, leveraging summary data from GWAS, to evaluate the potential causal effects of depression on three COVID-19 outcomes. Furthermore, we investigated the causal effects of antidepressants on COVID-19 outcomes. The COVID-19 datasets contain information on various stages of the disease, including SARS-CoV-2 infection (N = 2,597,856), hospitalized COVID-19 (N = 2,095,324), and critical COVID-19 (N = 1,086,211). Datasets for depression and antidepressants were comprised of 1,349,887 and 106,785 participants, respectively.

RESULTS

Employing the inverse variance-weighted (IVW) method, we show a causal association between depression and three COVID-19 outcomes. Specifically, we found that genetic liability to depression is linked to critical COVID-19 (OR: 1.28, 95 % CI: 1.13-1.46), hospitalized COVID-19 (OR: 1.23, 95 % CI: 1.13-1.34), and SARS-CoV-2 infection (OR: 1.06, 95 % CI: 1.02-1.10). Interestingly, the use of antidepressants was not associated with COVID-19, with the odds ratios for critical COVID-19 (OR: 1.05, 95 % CI: 0.88-1.26), hospitalization (OR: 1.01, 95 % CI: 0.90-1.13), and SARS-CoV-2 infection (OR: 1.03, 95 % CI: 0.99-1.08) indicating no causal impact.

CONCLUSION

Our study indicates that genetic liability to depression may increase the susceptibility to COVID-19 and its severe forms. The lack of causal effect of antidepressant use on COVID-19 implies antidepressant medication may counteract the detrimental effect of depression on COVID-19.

The gut microbiota-constipation connection: Insights from a two sample bidirectional Mendelian randomization study

OBJECTIVE

The dysbiosis of the gut microbiota has been implicated in various maladies. Research has identified an association between the dysbiosis of the gut microbiota and the risk of constipation, prompting this study to elucidate the potential causal relationship between gut microbiota imbalance with constipation through a two sample bidirectional Mendelian randomization (MR) study, shedding light on the genetic mechanisms underlying the connection between gut microbiota and constipation.

METHODS

The forward MR analysis aimed to scrutinize whether alterations in the composition and abundance of gut microbiota impact the risk of constipation, while the reverse MR analysis explored whether the genetic predisposition to constipation influences the abundance of gut microbiota. Genomic correlation data for the gut microbiota were sourced from the comprehensive statistics of the MiBioGen consortium. Genomic correlation data for constipation were obtained from the IEU database, encoded as the dataset ebi-a-GCST90018829. The correlation was assessed using various analytical techniques, including inverse variance weighting (IVW), Mendelian randomization-Egger regression (MR-Egger), and weighted median and mode methodologies. To ensure the robustness of the results, a meticulous sensitivity analysis was conducted, incorporating Cochran's Q test, MR-Egger intercept test, Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and a Leave-one-out analysis.

RESULTS

In the forward Mendelian randomization analyses, a negative correlation was discerned between the abundance of Coprococcus in the gut microbiota and the occurrence of constipation (IVW: OR = 0.74, 95 % CI = 0.64-0.86, p = 0.0001), whereas a positive correlation was observed between the abundance of Bacteroidetes in the gut microbiota and constipation (IVW: OR = 1.22, 95 % CI = 1.00-1.50, p = 0.04). In the forward Mendelian randomization analyses, we were unsuccessful in obtaining valid instrumental variables for scrutiny, and we deemed that constipation exerts no influence on the composition of the gut microbiota.

CONCLUSION

Genetic predisposition towards increased abundance of Coprococcus and decreased abundance of Bacteroidetes is correlated with a diminished susceptibility to constipation. This investigation showed that alterations in the gut microbiota precipitated the onset of constipation, rather than constipation inducing modifications in the microbial flora.

Inflammatory bowel disease and risk of autoimmune hepatitis: A univariable and multivariable Mendelian randomization study

OBJECTIVE

This study aimed to use Mendelian randomization (MR) to investigate the potential causal association between inflammatory bowel disease (IBD) and autoimmune hepatitis (AIH).

METHODS

Two-sample MR was performed to estimate the causal effect of IBD on AIH. The primary analysis employed the inverse variance weighted (IVW) method in univariable MR analysis, supplemented by additional methods including MR-Egger, weighted median, simple mode, and weighted mode. The p values were adjusted by FDR p-value adjustment. In the replication analysis, the primary IVW analysis was repeated and then pooled by meta-analysis. Sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out, and funnel plot analysis to evaluate the robustness of the MR findings. Additionally, multivariable MR (MVMR) was employed to estimate the direct causal effect of IBD on the risk of AIH.

RESULTS

In univariable MR analysis, a significant positive causal association was observed between IBD (both Crohn's disease (CD) or ulcerative colitis (UC)) and the risk of AIH (for CD and AIH, the IVW odds ratio (OR) = 1.10, 95% confidence interval (CI) = 1.00-1.16, P = 0.045, FDR P = 0.045; for UC and AIH, the IVW OR = 1.07, 95% CI = 1.00-1.13, P = 0.038, FDR P = 0.076). Furthermore, no significant positive correlation between IBD and the risk of AIH (OR = 1.13, 95% CI = 0.94-1.35, P = 0.194). Sensitivity analysis revealed no pleiotropic bias. MVMR analysis further confirmed the direct causal effect of CD or UC on the risk of AIH after adjusting for the common risk factors (cigarettes per day and osteoporosis). In the replication analysis, the positive causal association between UC and the risk of AIH remain significant (the IVW odds ratio (OR) = 1.32, 95% CI = 1.18-1.48, P = 2.90E-06). While no significant positive association was observed between CD or IBD and the risk of AIH in the replication analysis, a suggestive positive association between the identified risk factors (UC, CD, and IBD) and the risk of AIH was detected in the meta-analysis (OR = 1.09, 95% CI = 1.05-1.13, P<0.0001).

CONCLUSION

This MR study revealed a positive impact of the identified risk factors (CD, UC and IBD) on the risk of AIH within the European population.

Association between inflammatory factors and melanoma: a bidirectional Mendelian randomization study

PURPOSE

This study performed a bidirectional Mendelian randomization (MR) analysis to elucidate the causal relationships of C-reactive protein and 41 inflammatory regulators with melanoma, including data from UK Biobank, Cardiovascular Risk in Young Finns Study, and Cohorts for Inflammation Work Group.

METHODS

We selected the inverse variance weighting (IVW) to merge the estimated causal effects of multiple SNPs into a weighted average. To evaluate the heterogeneities of IVW, the Cochran Q statistic, and I2 index were used. What's more, several sensitivity analyses were employed, including IVW, MR-Egger, weighted median, and Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO).

RESULTS

With SNPs reaching P < 5 × 10-8, the analyses findings revealed that IL-16 had a significant positively association with genetically risk of melanoma (ORIVW: 1.05; 95% CI: 1.03-1.07; P < 0.001), and high levels of MCP1 (ORIVW: 1.13; 95% CI: 1.03-1.23; P = 0.01) were suggestively associated with melanoma susceptibility. What's more, TNF-β (ORIVW: 1.07; 95% CI: 1.01-1.13; P = 0.02) and IL-8 (ORIVW: 1.08, 95% CI: 1.01-1.16; P = 0.03) were demonstrated a positive association with the risk of melanoma under a less stringent cut-off (P < 5 × 10-6). Conversely, we found a facilitative effect of melanoma susceptibility on IP-10 and inhibitory effects on IL-6, IL-1b, and GRO-α.

CONCLUSION

The genetic evidence that we have uncovered indicates a potential association between the levels of specific inflammatory markers (IL-16, IL-8, MCP-1, and TNF-β) and the risk of melanoma. Further research is imperative to translate these findings into clinical applications.

The "supercompensation" effect of children's lockdown during COVID-19: based on the analysis of changes in physical activity, sleep, and psychology

OBJECTIVE

To investigate the "supercompensation" effect of preschoolers during the coronavirus disease 2019 lockdown by comparing the changes in physical activity (PA), psychological, and sleep indicators before and after the lockdown.

METHODS

A total of 127 children (aged 3-6 years) were recruited. Before and after the lockdown, the children's PA levels were measured using the ActiGraph GT3X+, and their psychological and sleep indicators were measured using the Strengths and Difficulties Questionnaire (SDQ) and Child Sleep Habit Questionnaire (CSHQ), respectively.

RESULTS

Regarding PA, the children's total physical activity, low-intensity physical activity, and medium-intensity physical activity (MVPA) were higher after the lockdown than before the lockdown, with significant differences in MVPA (p < 0.05). Regarding psychology, the children's SDQ and multidimensional scores were better after the lockdown than before the lockdown, with a significant difference in SDQ scores (p < 0.05). Regarding sleep, the children's CSHQ scores were better after the lockdown than before the lockdown, with a highly significant difference in CSHQ scores (p < 0.01).

CONCLUSION

After lockdown, children's PA, psychological, and sleep effects were "supercompensated." In particular, the PA of preschoolers before, during, and after the lockdown may show a "baseline-inhibition-supercompensation" process.

Genetic liability to elevated circulating IP-10, IFNγ and SCGFβ levels in relation to thoracic aortic aneurysm: A mendelian randomization study

Inflammation is associated with thoracic aortic aneurysm (TAA) but the effects of each circulating inflammatory factor on TAA remain unclear. In this study, we explored the relationship between circulating inflammatory factors and TAA risk using Mendelian randomization (MR) approach based on summary statistics from the latest genome-wide association study (GWAS) of 41 circulating inflammatory factors in 8293 Finns and a GWAS involving 1351 TAA cases and 18,295 controls of European ancestry. In univariable MR, higher interferon gamma-induced protein 10 (IP-10) levels, higher interferon gamma (IFNγ) levels and higher stem cell growth factor beta (SCGFβ) levels were associated with an increased risk of TAA (OR = 1.37, 95 % CI = 1.17-1.59, p = 7.42 × 10-5; OR = 1.43, 95 % CI = 1.19-1.74, p = 2.04 × 10-4; OR = 1.27, 95 % CI = 1.09-1.48, p = 2.40 × 10-3, respectively). In multivariable MR, the patterns of associations for the three cytokines remained adjusting for each other or smoking, but were attenuated differently with adjustment for other cardiovascular risk factors, especially for lipids and body mass index. Bidirectional MR approach did not identify any significant associations between cytokines and risk factors. Our results indicated that circulating cytokines may play mediation roles in the pathogenesis of TAA. Further studies are needed to determine whether these biomarkers can be used to prevent and treat TAA.

Genetically identified mediators associated with increased risk of stroke and cardiovascular disease in individuals with autism spectrum disorder

Growing evidence suggested that individuals with autism spectrum disorder (ASD) associated with stroke and cardiovascular disease (CVD). However, the causal association between ASD and the risk of stroke and CVD remains unclear. To validate this, we performed two-sample Mendelian randomization (MR) and two-step mediation MR analyses, using relevant genetic variants sourced from the largest genome-wide association studies (GWASs). Two-sample MR evidence indicated causal relationships between ASD and any stroke (OR = 1.1184, 95% CI: 1.0302-1.2142, P < 0.01), ischemic stroke (IS) (OR = 1.1157, 95% CI: 1.0237-1.2160, P = 0.01), large-artery atherosclerotic stroke (LAS) (OR = 1.2902, 95% CI: 1.0395-1.6013, P = 0.02), atrial fibrillation (AF) (OR = 1.0820, 95% CI: 1.0019-1.1684, P = 0.04), and heart failure (HF) (OR = 1.1018, 95% CI: 1.0007-1.2132, P = 0.05). Additionally, two-step mediation MR suggested that type 2 diabetes mellitus (T2DM) partially mediated this effect (OR = 1.14, 95%CI: 1.02-1.28, P = 0.03). The mediated proportion were 10.96% (95% CI: 0.58%-12.10%) for any stroke, 11.77% (95% CI: 10.58%-12.97%) for IS, 10.62% (95% CI: 8.04%-13.20%) for LAS, and 7.57% (95% CI: 6.79%-8.36%) for HF. However, no mediated effect was observed between ASD and AF risk. These findings have implications for the development of prevention strategies and interventions for stroke and CVD in patients with ASD.

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.

Causal effects and metabolites mediators between immune cell and risk of breast cancer: a Mendelian randomization study

Introduction: The incidence and mortality of female breast cancer remain high, and the immune microenvironment of breast cancer has undergone significant alterations. However, the impact of blood immune cell levels on the risk of breast cancer is not fully understood. Therefor this study aims to investigate the causal relationship between blood immune cell levels and the risk of breast cancer. Methods: A Mendelian randomization (MR) analysis was employed to assess the causal relationship between immune cells and the risk of breast cancer, as along with their potential mediating factors. Genetic statistics of metabolites breast cancer and immune cells were obtained from the GWAS Catalog, while the genome-wide association study (GWAS) statistics of breast cancer were extracted from the UK biobank. Two-sample MR analysis were performed using inverse-variance weighted (IVW) to ascertain the causal association between immune cells and the risk of breast cancer. Furthermore, 1,400 metabolites were analyzed for their mediating role between immune cells and the risk of breast cancer. Results: MR analysis through IVW method revealed that genetically predicted CD24+ CD27+ B cells were associated with a decreased risk of breast cancer (OR = 0.9978, 95% CI: 0.996-0.999, p = 0.001), while IgD- CD38+ B cells were linked to an increased risk of breast cancer (OR = 1.002, 95% CI: 1.001-1.004, p = 0.005). Additional CD14+ CD16+ monocytes were associated with an increased risk of breast cancer (OR = 1.000, 95% CI: 1.000-1.001, p = 0.005). Mediation analysis revealed a positive causal relationship between IgD- CD38+ B cells and Glycerate levels, with the latter also exhibiting a positive causal relationship with the risk of breast cancer (p < 0.05). Conversely, IgD- CD38+ B cells displayed a negative causal relationship with Succinoyltaurine levels, and the latter also demonstrated a negative causal relationship with the risk of breast cancer (p < 0.05). Conclusion: This MR study provides novel genetic evidence supporting a causal relationship between IgD- CD38+ B cells and the risk of BC. Moreover, it is identified that IgD- CD38+ B cells contribute to an increased risk of BC through both positive and negative mediation effects involving Glycerate and Succinoyltaurine.

Causal relationship of interleukin-6 and its receptor on sarcopenia traits using mendelian randomization

BACKGROUND

Previous research has extensively examined the role of interleukin 6 (IL-6) in sarcopenia. However, the presence of a causal relationship between IL-6, its receptor (IL-6R), and sarcopenia remains unclear.

METHOD

In this study, we utilized summary-level data from genome-wide association studies (GWAS) focused on appendicular lean mass (ALM), hand grip strength, and walking pace. Single nucleotide polymorphisms (SNPs) were employed as genetic instruments for IL-6 and IL-6R to estimate the causal effect of sarcopenia traits. We adopted the Mendelian randomization (MR) approach to investigate these associations using the inverse variance weighted (IVW) method as the primary analytical approach. Additionally, we performed sensitivity analyses to validate the reliability of the MR results.

RESULT

This study revealed a significant negative association between main IL-6R and eQTL IL-6R on the left grip strength were - 0.013 (SE = 0.004, p < 0.001) and -0.029 (SE = 0.007, p < 0.001), respectively. While for the right grip strength, the estimates were - 0.011 (SE = 0.001, p < 0.001) and - 0.021 (SE = 0.008, p = 0.005). However, no evidence of an association for IL-6R with ALM and walking pace. In addition, IL-6 did not affect sarcopenia traits.

CONCLUSION

Our study findings suggest a negative association between IL-6R and hand grip strength. Additionally, targeting IL-6R may hold potential value as a therapeutic approach for the treatment of hand grip-related issues.

Causality of Genetically Determined Metabolites on Chronic Kidney Disease: A Two-Sample Mendelian Randomization Study In Silico

Introduction: Chronic kidney disease (CKD) is associated with metabolic disorders. However, the evidence for the causality of circulating metabolites to promote or prevent CKD is still lacking. Methods: The two-sample Mendelian randomization (MR) analysis was conducted to evaluate the latent causal relationship between the genetically proxied 486 blood metabolites and CKD. Genome-wide association study (GWAS) data for exposures were derived from 7824 European GWAS on metabolite levels, which have been extensively utilized in the medical field to elucidate the mechanisms underlying disease onset and progression. The random inverse variance weighted (IVW) is the primary analysis for causality analysis while MR-Egger and weighted median as complementary analyses. For the further identification of metabolites, reverse MR and linkage disequilibrium score regression were performed for further evaluation. The drug target for N-acetylornithine was subsequently supplemented into the analysis, with MR and colocalization analysis being utilized. Key metabolic pathways were identified via MetaboAnalyst 4.0 (https://www.metaboanalyst.ca/) online website. Results: N-acetylornithine was identified as a reliable metabolite that increases the susceptibility to estimated glomerular filtration rate (eGFR) decrease (β = 0.047; 95% confidence interval: -0.068 to -0.026; PIVW = 1.5E-5). The "glyoxylate and dicarboxylate metabolism" pathway showed significant relevance to CKD development (P = 6E-4), whereas the "glycine, serine, and threonine metabolism" pathway was also recognized as associated with CKD by general practitioners (P = 7E-4). Colocalization analysis revealed a robust genetic link between N-acetylornithine and both CKD and eGFR, with 85.1% and 99.4% colocalization rates, respectively. IVW-MR analysis substantiated these findings with a significant positive association for CKD (odds ratio = 1.43, P = 4.7E-5) and a negative correlation with eGFR (b = -0.04, P = 1.13E-31). Conclusions: MR was utilized to explore the potential causal links between 61 genetic serum metabolites and CKD. N-acetylornithine and NAT8 were further explored as a potential therapeutic target for CKD treatment.

Genetic Association between Lipid-Regulating Drug Targets and Diabetic Retinopathy: A Drug Target Mendelian Randomization Study

Background

Diabetic retinopathy (DR) is a diabetic microvascular complication and a leading cause of vision loss. However, there is a lack of effective strategies to reduce the risk of DR currently. The present study is aimed at assessing the causal effect of lipid-regulating targets on DR risk using a two-sample Mendelian randomization (MR) study.

Method

Genetic variants within or near drug target genes, including eight lipid-regulating targets for LDL-C (HMGCR, PCSK9, and NPC1L1), HDL-C (CETP, SCARB1, and PPARG), and TG (PPARA and LPL), were selected as exposures. The exposure data were obtained from the IEU OpenGWAS project. The outcome dataset related to DR was obtained from the FinnGen research project. Inverse-variance-weighted MR (IVW-MR) was used to calculate the effect estimates by each target. Sensitivity analyses were performed to verify the robustness of the results.

Results

There was suggestive evidence that PCSK9-mediated LDL-C levels were positively associated with DR, with OR (95% CI) of 1.34 (1.02-1.77). No significant association was found between the expression of HMGCR- and NPC1L1-mediated LDL-C levels; CETP-, SCARB1-, and PPARG-mediated HDL-C levels; PPARA- and LPL-mediated TG levels; and DR risk.

Conclusions

This is the first study to reveal a genetically causal relationship between lipid-regulating drug targets and DR risk. PCSK9-mediated LDL-C levels maybe positively associated with DR risk at the genetic level. This study provides suggestive evidence that PCSK9 inhibition may reduce the risk of DR.

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.

Exploring the link between gut microbiota and alopecia areata: a two-sample Mendelian randomization analysis

BACKGROUND

While observational studies have suggested a link between gut microbiota diversity and alopecia areata (AA), the causal relationship remains unclear.

METHODS

We leveraged data from the MiBioGen and FinnGen consortiums' Genome-wide association studies (GWAS) encompassing gut microbiota (n = 13,266) and AA (n = 211,428) datasets. A comprehensive Mendelian randomization (MR) and reverse MR approach were employed, utilizing five statistical methods to evaluate causality. Sensitivity analyses were also conducted to corroborate the MR results.

RESULTS

Inverse variance weighted (IVW) analysis indicated a protective effect against AA from Butyricimonas (OR = 0.37, 95% CI: 0.18-0.77, P = 0.01), Enterorhabdus (OR = 0.40, 95% CI: 0.16-0.95, P = 0.04), Eubacterium (xylanophilum group) (OR = 0.36, 95% CI: 0.15-0.84, P = 0.02), and Phascolarctobacterium (OR = 0.37, 95% CI: 0.15-0.91, P = 0.03), while Ruminococcaceae UCG003 posed as a risk factor (OR = 2.79, 95% CI: 1.27-6.14, P = 0.01). Reverse MR showed no significant causal link between AA and gut microbiota, with no significant heterogeneity or horizontal pleiotropy.

CONCLUSIONS

Our analysis suggests probable causality between certain gut microbiota and AA, shedding light on its pathogenesis and potential intervention strategies.

Causal relationships between interleukins, interferons and COVID-19 risk: a Mendelian randomization study

Observational studies have shown close associations between COVID-19 risk and cytokines, especially interleukins (ILs) and interferons (IFNs). However, the causal relationships between ILs, IFNs and COVID-19 were still unclear. To resolve the problem, we conducted a Mendelian randomization analysis between COVID-19 and 47 cytokines, including 35 ILs and 12 IFNs. First, three methods were applied to estimate causal effects by using single nucleotide polymorphisms as instrumental variables (IVs). Subsequently, the MR-Egger method was used to estimate the horizontal pleiotropy of IVs. Finally, sensitivity analyses were applied to assess the robustness of results. As a result, one IFN (IFN-W1) and five ILs (IL-5, IL-6, IL-13, IL-16 and IL-37) were identified to significantly decrease the COVID-19 risk. In contrast, one IFN (IFNG) and five ILs (IL-3, IL-8, IL-27, IL-31 and IL-36β) were found to be significantly associated with an increased risk of COVID-19. In summary, the findings of this study provide insights into potential therapeutic interventions for COVID-19.

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.

Genetic links between atopy, allergy, and alopecia areata: insights from a Mendelian randomization study

BACKGROUND

Alopecia areata (AA), a prevalent form of autoimmune hair loss, has a not well-defined relationship with atopic and allergic disorders, including eczema, hay fever, and asthma.

OBJECTIVES

This study aims to elucidate the genetic relationship between atopy, allergies, and alopecia areata (AA) using Mendelian randomization. We hypothesize that atopic and allergic conditions contribute to the genetic predisposition of AA.

METHODS

We analyzed extensive genetic data from Genome-wide Association Studies (GWAS) involving over one million individuals. This analysis focused on assessing the genetic correlation between AA and various allergic conditions, including hay fever, eczema, asthma, and allergies to pollen, dust, and cats. The inverse variance weighted method served as our primary analytical tool, complemented by sensitivity analyses to verify the robustness of our results.

RESULTS

Our findings reveal a significant genetic correlation between atopy/allergies and an increased risk of AA. Notably, strong associations were observed for hay fever, eczema, asthma, and specific allergies (pollen, dust, and cats). The sensitivity analyses corroborated these associations, reinforcing the reliability of our primary results.

CONCLUSIONS

This study provides compelling genetic evidence of an association between atopic and allergic conditions and the development of AA. These findings suggest that individuals with such conditions may benefit from enhanced surveillance for early signs of AA.

Causal associations of male infertility with stroke: a two-sample Mendelian randomization study

Background

Stroke is a devastating global health issue, with high mortality and disability rates. The increasing prevalence of male infertility among reproductive-aged men has become a growing concern worldwide. However, the relationship between male infertility and stroke incidence remains uncertain. This study aimed to address this knowledge gap by employing a Mendelian randomization (MR) approach.

Method

Utilizing genetic instrumental variables derived from a genome-wide association study (GWAS) on male infertility and stroke, a two-sample MR design was implemented. Five different analysis methods, with inverse-variance weighted as the primary approach, were used to examine the genetic causal associations between male infertility and various stroke subtypes. Heterogeneity analysis, pleiotropy tests, and leave-one-out validation were conducted to assess heterogeneity, evaluate pleiotropy, and ensure the robustness of the findings.

Result

The results indicate a potential lower risk of small vessel stroke associated with male infertility (odds ratio, 95% confidence interval: 0.82, 0.68 to 0.99, p=0.044), although no significant impact on other stroke subtypes was observed. The study exhibited low heterogeneity and no apparent pleiotropy; however, the stability of the results was not optimal.

Conclusion

Male infertility might potentially confer a protective effect against small vessel stroke risk. Caution is warranted due to potential confounding factors. Additional studies are necessary to confirm these findings and provide further validation.

Lifestyle factors, glycemic traits, and lipoprotein traits and risk of liver cancer: a Mendelian randomization analysis

The current state of knowledge on the relationship between lifestyle factors, glycemic traits, lipoprotein traits with liver cancer risk is still uncertain despite some attempts made by observational studies. This study aims to investigate the causal genetic relationship between factors highly associated with liver cancer incidence by using Mendelian randomization (MR) analysis. Employing MR analysis, this study utilized previously published GWAS datasets to investigate whether lifestyle factors, glycemic traits, and lipoprotein traits would affect the risk of liver cancer. The study utilized three MR methods, including inverse variance-weighted model (IVW), MR Egger, and weighted median. Furthermore, MR-Egger analyses were performed to detect heterogeneity in the MR results. The study also conducted a leave-one-out analysis to assess the potential influence of individual SNPs on the MR analysis results. MR-PRESSO was used to identify and remove SNP outliers associated with liver cancer. MR analyses revealed that 2-h glucose (odds ratio, OR 2.33, 95% confidence interval, CI 1.28-4.21), type 2 diabetes mellitus (T2DM, OR 1.67, 95% CI 1.18-2.37), body mass index (BMI, OR 1.67, 95% CI 1.18-2.37), waist circumference (OR 1.78, 95% CI 1.18-2.37) were associated with increased risk of liver cancer. On the contrary, apolipoproteins B (APOB, OR 0.67, 95% CI 0.47-0.97), and low-density lipoprotein (LDL, OR 0.62, 95% CI 0.42-0.92) were negatively related to liver cancer risk. Additionally, after adjusting for BMI, apolipoproteins A-I (APOA-I, OR 0.56, 95% CI, 0.38-0.81), total cholesterol (TC, OR 0.72, 95% CI, 0.54-0.94), and total triglycerides (TG, OR 0.57, 95% CI, 0.40-0.78) exhibited a significant inverse correlation with the risk of liver cancer. This study supports a causal relationship between 2-h glucose, T2DM, BMI, and waist circumference with the increased risk of liver cancer. Conversely, the study reveals a cause-effect relationship between TC, TG, LDL, APOA-I, and APOB with a decreased risk of liver cancer.

Effect of coffee, tea and alcohol intake on circulating inflammatory cytokines: a two sample-Mendelian randomization study

BACKGROUND

Despite the abundance of research examining the effects of coffee, tea, and alcohol on inflammatory diseases, there is a notable absence of conclusive evidence regarding their direct causal influence on circulating inflammatory cytokines. Previous studies have primarily concentrated on established cytokines, neglecting the potential impact of beverage consumption on lesser-studied but equally important cytokines.

METHODS

Information regarding the consumption of coffee, tea, and alcohol was collected from the UK Biobank, with sample sizes of 428,860, 447,485, and 462,346 individuals, respectively. Data on 41 inflammatory cytokines were obtained from summary statistics of 8293 healthy participants from Finnish cohorts.

RESULTS

The consumption of coffee was found to be potentially associated with decreased levels of Macrophage colony-stimulating factor (β = -0.57, 95% CI -1.06 ~ -0.08; p = 0.022) and Stem cell growth factor beta (β = -0.64, 95% CI -1.16 ~ -0.12; p = 0.016), as well as an increase in TNF-related apoptosis-inducing ligand (β = 0.43, 95% CI 0.06 ~ 0.8; p = 0.023) levels. Conversely, tea intake was potentially correlated with a reduction in Interleukin-8 (β = -0.45, 95% CI -0.9 ~ 0; p = 0.045) levels. Moreover, our results indicated an association between alcohol consumption and decreased levels of Regulated on Activation, Normal T Cell Expressed and Secreted (β = -0.24, 95% CI -0.48 ~ 0; p = 0.047), as well as an increase in Stem cell factor (β = 0.17, 95% CI 0.02 ~ 0.31; p = 0.023) and Stromal cell-derived factor-1 alpha (β = 0.20, 95% CI 0.04 ~ 0.36; p = 0.013).

CONCLUSION

Revealing the interactions between beverage consumption and various inflammatory cytokines may lead to the discovery of novel therapeutic targets, thereby facilitating dietary interventions to complement clinical disease treatments.

Associations between sex hormones, receptors, binding proteins and inflammatory bowel disease: a Mendelian randomization study

Background

Gender differences existed in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Observational studies have revealed associations between sex hormones and IBD, such as estrogen and testosterone. However, the exact relationship between these sex hormones and IBD is unclear.

Method

Based on the genome-wide association studies data of eight sex hormones, two sex hormone receptors, sex hormone-binding globulin (SHBG), total IBD and its two subtypes, we performed a two-sample Mendelian randomization (MR) study to analyze their mutual relationship. For estradiol (E2), progesterone (PROG), bioavailable testosterone (BAT), total testosterone (TT) and SHBG, sex-stratified MR analyses were also performed. Inverse variance weighted method, MR-Egger regression and Weighted median method were used for causal analyses. Sensitivity analyses were conducted to test the stability of causal relationships. Besides, a reverse MR analysis was performed to estimate the reverse causation.

Results

E2 (P=0.028) and TT (P=0.034) had protective effects on CD. Sex-stratified analyses revealed protective roles of E2 in males on total IBD (P=0.038) and CD (P=0.020). TT in females had protective effects on total IBD (P=0.025) and CD (P=0.029), and BAT in females decreased the risk of developing CD (P=0.047) and UC (P=0.036). Moreover, SHBG in males was also associated with a decreased risk of CD (P=0.021). The reversed MR analysis showed that CD was negatively correlated with estrogen receptor (P=0.046). UC was negatively correlated with PROG in females (P=0.015) and positively correlated with SHBG levels in males (P=0.046).

Conclusion

Findings of this study revealed the mutual causal associations between sex hormones and the risk of developing IBD.

Sex hormones and neuromyelitis optica spectrum disorder: a bidirectional Mendelian randomization study

BACKGROUND

Females are considered to have an increased susceptibility to neuromyelitis optica spectrum disorder (NMOSD) than males, especially aquaporin-4 (AQP4) antibody positive NMOSD, indicating that sex hormones may be involved in the NMOSD pathogenesis. However, the causality between sex hormones and NMOSD still remains unclear.

METHODS

Based on the genome-wide association study (GWAS) data of three sex hormones (estradiol (E2), progesterone (PROG) and bioavailable testosterone (BAT)), sex hormone-binding globulin (SHBG), age of menarche, age of menopause, and NMOSD (total, AQP4 + and AQP4 -), we performed a two-sample bidirectional Mendelian randomization (MR) study. Sex-stratified GWAS data of E2, PROG, BAT, and SHBG was obtained for gender-specific MR analysis. Causal inferences were based on the inverse variance weighted method, MR-Egger regression, and weighted median method. The reverse MR analysis was also performed to assess the impact of NMOSD on hormone levels.

RESULTS

PROG in females had aggravative effects on NMOSD (P < 0.001), especially AQP4 - NMOSD (P < 0.001). In the reverse MR analysis, total NMOSD was found to decrease the level of BAT (P < 0.001) and increase the level of SHBG (P = 0.001) in females.

CONCLUSION

Findings of this MR analysis revealed mutual causal associations between sex hormones and NMOSD, which provided novel perspectives about the gender-related pathogenesis of NMOSD.

Association of congenital iodine deficiency syndrome and differentiated thyroid cancer: a Mendelian randomization study

BACKGROUND

The effect of iodine deficiency, especially during the fetal period, on thyroid cancer risk remains unclear. The evidence from observational studies is controversial because of the inevitable confounding factors. We studied the causal effect of congenital iodine deficiency on differentiated thyroid cancer (DTC) based on Mendelian randomization (MR).

METHODS

Two-Sample MR analysis was performed using data from published genome-wide association studies, including congenital iodine deficiency syndrome (CIDS) (353 cases, 187,684 controls) and DTC (649 cases, 431 controls) data.

RESULTS

There was a causal relationship between CIDS and DTC (P < 0.05), with CIDS increasing the DTC risk by 37.4% (OR = 1.374, 95%CI = 1.110-1.700). Heterogeneity tests and tests of multiple validities indicated that the results were solid and reliable (all P < 0.05).

CONCLUSIONS

Fetal iodine deficiency increases the risk of DTC, so future clinical studies should focus on the effect of iodine supplementation during pregnancy to reduce the risk of thyroid cancer in the offspring.

The causal relationship between physical activity, sedentary behavior and brain cortical structure: a Mendelian randomization study

Physical activity and sedentary behavior, both distinct lifestyle behaviors associated with brain health, have an unclear potential relationship with brain cortical structure. This study aimed to determine the causal link between physical activity, sedentary behavior, and brain cortical structure (cortical surface area and thickness) through Mendelian randomization analysis. The inverse-variance weighted method was primarily utilized, accompanied by sensitivity analyses, to confirm the results' robustness and accuracy. Analysis revealed nominally significant findings, indicating a potential positive influence of physical activity on cortical thickness in the bankssts (β = 0.002 mm, P = 0.043) and the fusiform (β = 0.002 mm, P = 0.018), and a potential negative association of sedentary behavior with cortical surface area in the caudal middle frontal (β = -34.181 mm2, P = 0.038) and the pars opercularis (β = -33.069 mm2, P = 0.002), alongside a nominally positive correlation with the cortical surface area of the inferior parietal (β = 58.332 mm2, P = 0.035). Additionally, a nominally significant negative correlation was observed between sedentary behavior and cortical thickness in the paracentral (β = -0.014 mm, P = 0.042). These findings offer insights into how lifestyle behaviors may influence brain cortical structures, advancing our understanding of their interaction with brain health.

Genetically determined metabolites in allergic conjunctivitis: A Mendelian randomization study

Background

Allergic conjunctivitis (AC) afflicts a significant portion of the global populace. Yet, its metabolic foundations remain largely unexplored.

Methods

We applied Mendelian Randomization (MR) and Linkage Disequilibrium Score Regression (LDSC) to scrutinize a cohort comprising 20 958 AC cases and 356 319 controls. Data were amalgamated from the metabolomics GWAS server and the FinnGen project, under strict quality control protocols.

Results

Using two-sample MR analysis, 486 blood metabolites were investigated in relation to AC. The IVW approach highlighted 18 metabolites as closely tied to AC risk; of these, 16 retained significance post sensitivity assessments for heterogeneity and horizontal pleiotropy. LDSC analysis, adopted to bolster our findings and negate confounders from shared genetic markers, revealed 8 metabolites with marked heritability, including: palmitate (OR = 0.614), 3-methoxytyrosine (OR = 0.657), carnitine (OR = 1.368), threonate (OR = 0.828), N-[3-(2-Oxopyrrolidin-1-yl)propyl]acetamide (OR = 1.257), metoprolol acid metabolite (OR = 0.982), oleoylcarnitine (OR = 0.635), and 2-palmitoylglycerophosphocholine (OR = 1.351).

Conclusion

AC is precipitated by ocular responses to environmental allergens. Our study unveils a causal link between 8 blood metabolites and AC. This insight accentuates the role of metabolites in AC onset, suggesting novel avenues for its early prediction, targeted prevention, and tailored therapeutic interventions.

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.

Higher level of physical activity reduces mental and neurological symptoms during and two years after COVID-19 infection in young women

Previous studies found that regular physical activity (PA) can lower the risk of SARS-CoV-2 (COVID-19) infection and post-COVID-19 condition (PCC), yet its specific effects in young women have not yet been investigated. Thus, we aimed to examine whether regular physical activity reduces the number of symptoms during and after COVID-19 infection among young women aged between 18 and 34 (N = 802), in which the confounding effect of other morbidities could be excluded. The average time since infection was 23.5 months. Participants were classified into low, moderate, and high PA categories based on the reported minutes per week of moderate and vigorous PA. Using the Post-COVID-19 Case Report Form, 50 different symptoms were assessed. Although regular PA did not decrease the prevalence of COVID-19 infection and PCC but significantly reduced the number of mental and neurological symptoms both in acute COVID-19 and PCC. Importantly, the high level of PA had a greater impact on health improvements. In addition, the rate of reinfection decreased with an increased level of PA. In conclusion, a higher level of regular PA can reduce the risk of reinfection and the number of mental and neurological symptoms in PCC underlying the importance of regular PA, even in this and likely other viral disease conditions.

Exploring the link between walking and lung cancer risk: a two-stage Mendelian randomization analysis

BACKGROUND

Previous observational research showed a potential link between physical activities such as walking and the risk of lung cancer. However, Mendelian randomization (MR) studies suggested there was no association between moderate to vigorous physical activity and lung cancer risk. We speculated that specific physical activities may be associated with lung cancer risk. Consequently, we conducted an MR study to examine the potential relationship between walking and the risk of lung cancer.

METHODS

We collected genetic summary data from UK Biobank. After excluding SNPs with F values less than 10 and those associated with confounding factors, we conducted a MR analysis to assess the causal effects between different types of walk and lung cancer. We also performed sensitivity analysis to validate the robustness of our findings. Finally, we analyzed the possible mediators.

RESULTS

MR analysis showed number of days/week walked for 10 + minutes was associated with a reduced risk of lung cancer risk (OR = 0.993, 95% CI = 0.987-0.998, P = 0.009). Additionally, usual walking pace was identified as a potentially significant factor in lowering the risk (OR = 0.989, 95% CI = 0.980-0.998, P = 0.015). However, duration of walks alone did not show a significant association with lung cancer risk (OR = 0.991, 95%CI = 0.977-1.005, P = 0.216). The sensitivity analysis confirmed the robustness of these findings. And number of days/week walked for 10 + minutes could affect fed-up feelings and then lung cancer risk. There was a bidirectional relationship between usual walking pace and sedentary behaviors (time spent watching TV).

CONCLUSION

The study unveiled a genetically predicted causal relationship between number of days/week walked for 10 + minutes, usual walking pace, and the risk of lung cancer. The exploration of potential mediators of walking phenotypes and their impact on lung cancer risk suggests that specific physical activities may reduce the risk of lung cancer.

Epidemiologic and genetic associations of female reproductive disorders with depression or dysthymia: a Mendelian randomization study

Observational studies have previously reported an association between depression and certain female reproductive disorders. However, the causal relationships between depression and different types of female reproductive disorders remain unclear in terms of direction and magnitude. We conducted a comprehensive investigation using a two-sample bi-directional Mendelian randomization analysis, incorporating publicly available GWAS summary statistics. Our aim was to establish a causal relationship between genetically predicted depression and the risk of various female reproductive pathological conditions, such as ovarian dysfunction, polycystic ovary syndrome(PCOS), ovarian cysts, abnormal uterine and vaginal bleeding(AUB), endometriosis, leiomyoma of the uterus, female infertility, spontaneous abortion, eclampsia, pregnancy hypertension, gestational diabetes, excessive vomiting in pregnancy, cervical cancer, and uterine/endometrial cancer. We analyzed a substantial sample size, ranging from 111,831 to 210,870 individuals, and employed robust statistical methods, including inverse variance weighted, MR-Egger, weighted median, and MR-PRESSO, to estimate causal effects. Sensitivity analyses, such as Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and funnel plots, were also conducted to ensure the validity of our results. Furthermore, risk factor analyses were performed to investigate potential mediators associated with these observed relationships. Our results demonstrated that genetic predisposition to depression or dysthymia was associated with an increased risk of developing PCOS (OR = 1.43, 95% CI 1.28-1.59; P = 6.66 × 10-11), ovarian cysts (OR = 1.36, 95% CI 1.20-1.55; P = 1.57 × 10-6), AUB (OR = 1.41, 95% CI 1.20-1.66; P = 3.01 × 10-5), and endometriosis (OR = 1.43, 95% CI 1.27-1.70; P = 2.21 × 10-7) after Bonferroni correction, but no evidence for reverse causality. Our study did not find any evidence supporting a causal or reverse causal relationship between depression/dysthymia and other types of female reproductive disorders. In summary, our study provides evidence for a causal relationship between genetically predicted depression and specific types of female reproductive disorders. Our findings emphasize the importance of depression management in the prevention and treatment of female reproductive disorders, notably including PCOS, ovarian cysts, AUB, and endometriosis.

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.

The Association Between SHBG and Osteoporosis: A NHANES Cross-Sectional Study and A Bidirectional Mendelian Randomization

This study aimed to examine the association between sex hormone-binding globulin (SHBG) and osteoporosis through a cross-sectional study and a two-sample bidirectional Mendelian randomization (MR). We used the National Health and Nutrition Examination Survey (NHANES) 2013-2014 and 2015-2016 data, with exposure as serum SHBG and outcome as osteoporosis and performed multivariate logistic regression to test the correlation between SHBG and osteoporosis. To determine the causal relationship between SHBG and osteoporosis, a two-sample bidirectional MR was employed. The genome-wide association study (GWAS) dataset for SHBG (n = 189,473) was obtained from the IEU database, and the GWAS dataset for osteoporosis (n = 212,778) was obtained from the FinnGen bioBank. The principal MR technique was inverse-variance weighting (IVW). In MR analyses, the MR-Egger intercept and Cochran Q test were used to detect multiple validity and horizontal heterogeneity. 1249 older adult participants (age ≥ 60) were involved in the cross-sectional study, including 113 osteoporosis cases. We identified a significant relationship between circulating SHBG concentration and osteoporosis risk [OR 3.963, 95% CI (2.095-7.495), P < 0.05]. Subgroup analysis indicated that SHBG was closely linked to the risk of osteoporosis in the female population [OR 1.008, 95% CI (1.002-1.013), P = 0.005] but not in males (P = 0.065). In addition, The IVW approach suggested a causal connection between SHBG and increased osteoporosis risk [OR 1.479, 95% CI (1.144-1.912), P = 0.003], and the MR-Egger intercept and the Cochran Q test validated the consistency of the MR results. Finally, the reverse MR analysis declined to identify a causal relation between SHBG and osteoporosis. Our research demonstrates a significant causal connection between circulating SHBG levels and increased osteoporosis risk. These results indicate that high SHBG may be associated with the risk of osteoporosis in postmenopausal women, but more research is needed.

Evaluating the effects of circulating inflammatory proteins as drivers and therapeutic targets for severe COVID-19

Objective

The relationships between circulating inflammatory proteins and COVID-19 have been observed in previous cohorts. However, it is not unclear which circulating inflammatory proteins may boost the risk of or protect against COVID-19.

Methods

We performed Mendelian randomization (MR) analysis using GWAS summary result of 91 circulating inflammation-related proteins (N = 14,824) to assess their causal impact on severe COVID-19. The COVID-19 phenotypes encompassed both hospitalized (N = 2,095,324) and critical COVID-19 (N = 1,086,211). Moreover, sensitivity analyses were conducted to evaluate the robustness and reliability.

Results

We found that seven circulating inflammatory proteins confer positive causal effects on severe COVID-19. Among them, serum levels of IL-10RB, FGF-19, and CCL-2 positively contributed to both hospitalized and critical COVID-19 conditions (OR: 1.10~1.16), while the other 4 proteins conferred risk on critical COVID-19 only (OR: 1.07~1.16), including EIF4EBP1, IL-7, NTF3, and LIF. Meanwhile, five proteins exert protective effects against hospitalization and progression to critical COVID-19 (OR: 0.85~0.95), including CXCL11, CDCP1, CCL4/MIP, IFNG, and LIFR. Sensitivity analyses did not support the presence of heterogeneity in the majority of MR analyses.

Conclusions

Our study revealed risk and protective inflammatory proteins for severe COVID-19, which may have vital implications for the treatment of the disease.

Particulate matter 2.5 causally increased genetic risk of autism spectrum disorder

BACKGROUND

Growing evidence suggested that particulate matter (PM) exhibit an increased risk of autism spectrum disorder (ASD). However, the causal association between PM and ASD risk remains unclear.

METHODS

We performed two-sample Mendelian randomization (MR) analyses, using instrumental variables (IVs) sourced from the largest genome-wide association studies (GWAS) databases. We employed three MR methods: inverse-variance weighted (IVW), weighted median (WM), and MR-Egger, with IVW method serving as our primary MR method. Sensitivity analyses were performed to ensure the stability of these findings.

RESULTS

The MR results suggested that PM2.5 increased the genetic risk of ASD (β = 2.41, OR = 11.13, 95% CI: 2.54-48.76, P < 0.01), and similar result was found for PM2.5 absorbance (β = 1.54, OR = 4.67, 95% CI: 1.21-18.01, P = 0.03). However, no such association was found in PM10 (β = 0.27, OR = 1.30, 95% CI: 0.72-2.36, P = 0.38). After adjusting for the false discovery rate (FDR) correction, our MR results remain consistent. Sensitivity analyses did not find significant heterogeneity or horizontal pleiotropy.

CONCLUSIONS

Our findings indicate that PM2.5 is a potential risk factor for ASD. Effective strategies to mitigate air pollutants might lead to a reduced incidence of ASD.

Causal effect of systemic lupus erythematosus on psychiatric disorders: A two-sample Mendelian randomization study

BACKGROUND

This study aims to investigate the association between systemic lupus erythematosus (SLE) and the risk of seven psychiatric disorders through the application of Mendelian randomization (MR) analysis due to previous observational studies that have suggested a potential link between SLE and psychiatric disorders.

METHODS

We collected genetic instruments for SLE from a genome-wide association study (GWAS) involving 23,210 individuals. Seven psychiatric traits were enrolled from the recent largest GWAS, including major depression disorder (MDD), generalized anxiety disorder (GAD), schizophrenia (SCZ), bipolar disorder (BID), autism spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), and insomnia. Summary statistics for psychiatric disorders were obtained from different GWAS meta-analysis studies. The inverse variance weighted (IVW) method was used as the main MR analysis.

RESULTS

The IVW method indicated that SLE is associated with a higher risk of GAD (OR = 1.072, 95 % CI [1.017-1.129], P = 0.008) and SCZ (OR = 3.242, 95 % CI [1.578-6.660], P = 0.007). However, no evidence was found for the causal associations between SLE and other psychiatric disorders. Further analyses found no evidence of pleiotropy and heterogeneity.

CONCLUSIONS

This two-sample MR analysis provides evidence that genetically predicted SLE may increase the risk of GAD and SCZ in a European population. Future studies are needed to elucidate and investigate the mechanisms underlying these causal relationships. Considering the existence of racial genomic heterogeneity, our findings must be viewed with caution.

No bidirectional relationship between inflammatory bowel disease and diverticular disease: a genetic correlation and Mendelian randomization study

Background: Although previous studies found that inflammatory bowel disease (IBD) and diverticular disease (DD) usually co-exist clinically, studies examining the relationship are spare. Aim: Our study aspires to investigate the causal correlation between the IBD [including ulcerative colitis (UC) and Crohn's disease (CD)] and DD using the Mendelian randomization (MR) analysis. Methods: We conducted a two-sample bidirectional MR analysis using publicly available genome-wide association studies (GWAS) summary data. The single nucleotide polymorphism (SNP) data associated with DD and IBD were obtained from the Finnish Biobank and UK Biobank, respectively. Through secondary data analysis of all GWAS summary data, we systematically screened genetic instrumental variables. To address the impact of horizontal pleiotropy, several methods were employed, including the inverse variance-weighted method (IVW), maximum likelihood method, Egger regression method, weighted median method, and simple median method. These approaches aimed to detect and correct for the potential bias caused by horizontal pleiotropy. Results: Genetically predicted DD did not have a causal effect on IBD (OR 1.06, 95% CI 0.98-1.17, p = 0.15), and had no causal effect on UC (OR 1.10, 95% CI 0.94-1.20, p = 0.36) and CD (OR 1.03, 95% CI 0.92-1.16, p = 0.62) either. Furthermore, in the reverse MR analysis, we did not observe any significant causal effect of IBD on DD. Results of complementary methods showed consistent results with those of the IVW method. Conclusion: This study's findings do not provide evidence for a causal relationship between IBD and DD, which contradicts the majority of observational studies.

The association between sedentary behavior and obstructive sleep apnea: a cross-sectional study from the NHANES (2007-2008 to 2015-2020)

BACKGROUND

Sedentary behavior (SB) may contribute to obesity and lower extremity fluid retention, which may favor the development of obstructive sleep apnea (OSA). However, linking sedentary behavior to OSA is unclear. The purpose of this study was to determine if there is an association between SB and OSA.

METHODS

Three typical questions in the NHANES questionnaire(①The frequency of feeling excessively sleepy per month. ②The frequency of gasping, snorting or stopping breathing per week. ③The frequency of snoring per week.) have been used for the assessment of OSA. A physical activity questionnaire(On a typical day, the amount of time you spend sitting or reclining.) was used to assess SB. This secondary analysis included National Health and Nutrition Examination Survey (NHANES) participants (unweighted = 20,115). Weighted sample and multiple logistic regression complex sample analysis techniques were used in this study.

RESULTS

After adjustment for confounders, participants with SB(> 8 h/d) had a higher risk of OSA compared to SB(< 4 h/d). Stratified analysis by gender showed that there was no significant association of SB and OSA in men. However, in women, with SB(< 4 h/d) as the reference, participants with(≥ 4 h/d) had an increased risk of OSA. By age-stratified analysis, the association of SB with OSA was stronger among older participants.

CONCLUSION

Analysis in this study showed a positive association between SB and OSA, more pronounced in women and participants older than 60 years old.

Genetic evidence of the causal relationship between chronic liver diseases and musculoskeletal disorders

BACKGROUND

Chronic liver diseases constitute a major global public health burden, posing a substantial threat to patients' daily lives and even survival due to the potential development of musculoskeletal disorders. Although the relationship between chronic liver diseases and musculoskeletal disorders has received extensive attention, their causal relationship has not been comprehensively and systematically investigated.

METHODS

This study aimed to assess the causal relationships between viral hepatitis, primary biliary cholangitis, primary sclerosing cholangitis (PSC), liver cirrhosis, and hepatocellular carcinoma (HCC) with osteoporosis, osteoarthritis, and sarcopenia through bidirectional Mendelian randomization (MR) research. The traits related to osteoporosis and osteoarthritis included both overall and site-specific phenotypes, and the traits linked to sarcopenia involved indicators of muscle mass and function. Random-effect inverse-variance weighted (IVW), weighted median, MR-Egger, and Causal Analysis Using the Summary Effect Estimates were used to evaluate causal effects, with IVW being the main analysis method. To enhance robustness, sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept, MR-PRESSO global test, funnel plots, leave-one-out analyses, and latent causal variable model.

RESULTS

The forward MR analysis indicated that PSC can reduce forearm bone mineral density (beta = - 0.0454, 95% CI - 0.0798 to - 0.0110; P = 0.0098) and increase the risk of overall osteoarthritis (OR = 1.012, 95% CI 1.002-1.022; P = 0.0247), while HCC can decrease grip strength (beta = - 0.0053, 95% CI - 0.008 to - 0.0025; P = 0.0002). The reverse MR analysis did not find significant causal effects of musculoskeletal disorders on chronic liver diseases. Additionally, no heterogeneity or pleiotropy was detected.

CONCLUSIONS

These findings corroborate the causal effects of PSC on osteoporosis and osteoarthritis, as well as the causal impact of HCC on sarcopenia. Thus, the implementation of comprehensive preventive measures is imperative for PSC and HCC patients to mitigate the risk of musculoskeletal disorders, ultimately improving their quality of life.

Gender-Related Effectiveness of Personalized Post-COVID-19 Rehabilitation

Background: Post-COVID-19 syndrome (PCS) may affect a substantial proportion of patients who have had COVID-19. The rehabilitation program might improve the physical capacity, functioning of the cardiopulmonary system, and mental conditions of these patients. This study aimed to investigate the effectiveness of personalized rehabilitation in patients with PCS according to gender. Methods: Adults who underwent a 6-week personalized PCS rehabilitation program were enrolled in a prospective post-COVID-19 Rehabilitation (PCR-SIRIO 8) study. The initial visit and the final visit included the hand-grip strength test, the bioimpedance analysis of body composition, and the following scales: modified Borg's scale, Modified Fatigue Impact Scale (MFIS), Functioning in Chronic Illness Scale (FCIS), modified Medical Research Council (mMRC) dyspnea scale, and tests: 30 s chair stand test (30 CST), Six-Minute Walk Test (6MWT), Short Physical Performance Battery test (SPPB)e. Results: A total of 90 patients (54% female) underwent the rehabilitation program. Rehabilitation was associated with an increase in skeletal muscle mass (24.11 kg vs. 24.37 kg, p = 0.001) and phase angle (4.89° vs. 5.01°, p = 0.001) and with a reduction in abdominal fat tissue volume (3.03 L vs. 2.85 L, p = 0.01), waist circumference (0.96 m vs. 0.95 m, p = 0.001), and hydration level (83.54% vs. 82.72%, p = 0.001). A decrease in fat tissue volume and an increase in skeletal muscle mass were observed only in females, while an increase in grip strength was noticed selectively in males. Patients' fatigue (modified Borg's scale, MFIS), physical capacity (30 CST, 6MWT), balance (SPPB), dyspnea (mMRC), and functioning (FICS) were significantly improved after the rehabilitation regardless of gender. Conclusions: Personalized rehabilitation improved the body composition, muscle strength, and functioning of patients diagnosed with PCS. The beneficial effect of rehabilitation on body composition, hydration, and phase angle was observed regardless of gender.

The causal relationship between gut microbiota and COVID-19: A two-sample Mendelian randomization analysis

Recent studies have shown that gut microbiota is associated with coronavirus disease 2019 (COVID-19). However, the causal impact of the gut microbiota on COVID-19 remains unclear. We performed a bidirectional Mendelian randomization. The summary statistics on the gut microbiota from the MiBioGen consortium. Summary statistics for COVID-19 were obtained from the 6th round of the COVID-19 Host Genetics Initiative genome-wide association study meta-analysis. Inverse variance weighting was used as the main method to test the causal relationship between gut microbiota and COVID-19. Reverse Mendelian randomization analysis was performed. Mendelian randomization analysis showed that Intestinimas.id.2062 was associated with an increased risk of severe COVID-19. Bifidobacterium.id.436, LachnospiraceaeUCG010.id.11330, RikenellaceaeRC9gutgroup.id.11191 increase the risk of hospitalized COVID-19. RuminococcaceaeUCG014.id.11371 shows the positive protection on hospitalized COVID-19. There is no causal relationship between gut microbiota and infection with COVID-19. According to the results of reverse Mendelian randomization analysis, no significant causal effect of COVID-19 on gut microbiota was found. The study found that gut microbiota with COVID-19 has a causal relationship. This study provides a basis for the theory of the gut-lung axis. Further randomized controlled trials are needed to clarify the protective effect of probiotics against COVID-19 and the specific protective mechanisms. This study has important implications for gut microbiota as a nondrug intervention for COVID-19.

Investigating the shared genetic architecture between COVID-19 and obesity: a large-scale genome wide cross-trait analysis

Observational studies have reported high comorbidity between obesity and severe COVID-19. The aim of this study is to explore whether genetic factors are involved in the co-occurrence of the two traits. Based on the available genome-wide association studies (GWAS) summary statistics, we explored the genetic correlation and performed cross-trait meta-analysis (CPASSOC) and colocalization analysis (COLOC) to detect pleiotropic single nucleotide polymorphisms (SNPs). At the genetic level, we obtained genes detected by Functional mapping and annotation (FUMA) and the Multi-marker Analysis of GenoMic Annotation (MAGMA). Potential functional genes were further investigated by summary-data-based Mendelian randomization (SMR). Finally, the casualty was identiied using the latent causal variable model (LCV). A significant positive genetic correlation was revealed between obesity and COVID-19. We found 331 shared genetic SNPs by CPASSOC and 13 shared risk loci by COLOC. At the genetic level, We obtained 3546 pleiotropic genes, among which 107 genes were found to be significantly expressed by SMR. Lastly, we observed these genes were mainly enriched in immune pathways and signaling transduction. These indings could provide new insights into the etiology of comorbidity and have implications for future therapeutic trial.

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.

The Impact of Different Intensities of Physical Activity on Serum Urate and Gout: A Mendelian Randomization Study

Physical activity is a potential protective factor against gout, but the role of exercise intensity in this context remains unclear. To overcome the limitations of observational studies in causal inference, this study employed a two-sample Mendelian randomization approach to explore the impact of different genetically proxied/predicted intensities of physical activity on serum urate concentration and the incidence of gout. Our data related to physical activity, serum urate, and gout were obtained from the UK Biobank, the Global Urate Genetics Consortium (GUGC), and the FinnGen dataset, respectively. Walking was included as representative of typical low-intensity physical activity in the analysis, and the other two types were moderate and vigorous physical activities. The estimation methods we used included the inverse-variance-weighted (IVW) method, MR-Egger regression, weighted-median method, simple-mode method, and weighted-mode method. Sensitivity analyses involved Rucker's framework, Cochran's Q test, funnel plots, MR-PRESSO outlier correction, and leave-one-out analysis. We found suggestive evidence from the inverse-variance-weighted method that moderate physical activity was a potential factor in reducing the incidence of gout (OR = 0.628, p = 0.034), and this association became more substantial in our subsequent sensitivity analysis (OR = 0.555, p = 0.006). However, we observed no distinctive effects of physical activity on serum urate concentration. In conclusion, our study supports some findings from observational studies and emphasizes the preventive role of moderate physical activity against gout. Given the limitations of the existing datasets, we call for future reexamination and expansion of our findings using new GWAS data.

The Causal Effect of Gut Microbiota on the Development of Idiopathic Normal Pressure Hydrocephalus

BACKGROUND

Older people are particularly at risk for idiopathic normal pressure hydrocephalus (iNPH), a rare neurological condition without known risk factors. Several recent observational studies have reported that gut microbiota composition is associated with iNPH. However, the causal impact of gut microbiota on iNPH is unknown.

METHODS

Single nucleotide polymorphisms strongly associated with 196 gut microbiota (18,340 individuals) were selected as instrumental factors, and the results were iNPH data (322 cases of iNPH and 21,043 controls). Random effects, inverse variance weighting, weighted medians, and Mendelian random (MR) -Egger were used to investigate causal effects. The Cochran's Q test, funnel plot, leave-one-out analysis, MR-Egger intercept test, and outlier (Global) test were employed in the sensitivity analysis to identify and compensate for the presence of pleiotropy. The MR-Steiger test also examined the hypothesised connection between exposure and result.

RESULTS

Our findings are mainly based on the inverse variance weighting approach and support a causal relationship between 6 gut microbial taxa and iNPH. We observed an inverse association between the Eubacterium fissicatena group (P = 0.007) and Lactococcus (P = 0.038) and iNPH, whereas Adlercreutzia (P = 0.029), Dialister (P = 0.040), Romboutsia (P = 0.027), Sutterella (P = 0.019) may be associated with an increased risk of iNPH. The results of the sensitivity analysis were robust.

CONCLUSIONS

Our findings suggest that certain gut bacteria may enhance iNPH risk. Research is required to determine whether the societal impact of iNPH is lessened in older people by sensible control of their gut microbiota.

The relationship between sex hormone-binding protein and non-alcoholic fatty liver disease using Mendelian randomisation

BACKGROUND

The incidence of non-alcohol fatty liver disease (NAFLD) has been increasing annually with the improvement of living standards. Numerous epidemiological observations have linked sex hormone-binding protein (SHBG) levels to NAFLD. However, evidence of the causal role of SHBG in the development and progression of NAFLD is still absent. Therefore, a systematic assessment of the causal relationship is needed.

METHOD

A two-sample Mendelian randomisation (MR) analysis was conducted. Genome-wide association study (GWAS) data for SHBG were obtained online from the IEU database (ebi-a-GCST90012111) as exposure. GWAS data from the NAFLD of the Finngen consortium were used for preliminary analysis, while NAFLD data from another GWAS involving 8434 participants were used for replication and meta-analyses. Causal effects were investigated with inverse variance weighted (IVW), weighted median and MR-Egger regression. Sensitivity analyses including Cochran's Q test, leave-one-out analysis and MR-Egger intercept analysis were simultaneously conducted to assess heterogeneity and pleiotropy.

RESULTS

After rigorous selection, 179 single-nucleotide polymorphisms (SNPs) were identified as strongly correlated instrumental variables. Preliminary analysis suggested a significant causal relationship between genetically determined serum SHBG levels and NAFLD [odds ratio (OR) IVW  = .54, 95% confidence interval (CI) = .30-.98, p = .043], supported by the results of the replication analysis (ORIVW  = .61, 95% CI = .46-.81, p = .0006) and further meta-analysis (OR = .59, 95% CI = .46-.77, p < .0001).

CONCLUSION

The genetic tendency to high levels of SHBG was causally correlated with a reduced risk of NAFLD, indicating that circulating high levels of SHBG was a protective factor for NAFLD.

Exploring the impact of computer game playing on cognitive function, Alzheimer's disease risk, and brain-derived neurotrophic factor levels: Basic evidence from Mendelian randomization

Introduction

The potential positive impact of computer game playing on cognitive function and its potential role in reducing the risk of Alzheimer's disease (AD) has been suggested. However, current observational studies have certain limitations. We utilized Mendelian randomization (MR) alongside extensive genome-wide association study (GWAS) data to examine the relationship between computer game playing, cognitive function, risk of AD, and levels of brain-derived neurotrophic factor (BDNF).

Methods

We collected datasets on computer game playing, cognition function, risk of AD, and BDNF level from the IEU Open GWAS project. Causal effects were assessed using various MR methods, including inverse variance weighted (IVW), weighted median, MR-Egger, simple mode, and weighted mode. To ensure the accuracy of the results, sensitivity analyses were conducted.

Results

Our analysis revealed a significant association between computer game playing and cognitive function (β  =  0.801, 95% CI: 0.351, 1.328, P  =  0.001). There was no statistically significant association between computer game playing and either BDNF level or risk of AD (β  =  -0.112, 95%CI: -1.315, 1.091, P  =  0.855; OR = 1.000, 95% CI: 1.004, 0.997, P  =  0.891, respectively). We further confirmed the reliability of our evidence through the MR-Egger intercept test, MR-PRESSO global test, Cochran's Q test, and funnel plots.

Conclusion

The results of our study indicate that engaging in computer game playing may confer a safeguarding influence on cognitive function. This underscores the potential advantages associated with computer gaming. Nevertheless, given the constraints inherent in our research, further investigation is warranted to substantiate our findings and delve into the underlying mechanisms.

Association of Sedentary Lifestyle with Risk of Acute and Post-Acute COVID-19 Sequelae: A Retrospective Cohort Study

BACKGROUND

Evidence suggests that coronavirus disease 2019 (COVID-19) survivors could experience COVID-19 sequelae. Although various risk factors for COVID-19 sequelae have been identified, little is known about whether a sedentary lifestyle is an independent risk factor.

METHODS

In this retrospective cohort study, 4850 participants self-reported their COVID-19 sequelae symptoms between June and August 2022. A sedentary lifestyle included physical inactivity (<150 min/week of moderate-to-vigorous intensity physical activity) and prolonged sedentary behavior (≥10 h/day) before the fifth COVID-19 wave was recorded. Logistic regression analysis was performed to determine the relationships between sedentary lifestyle and risk of acute and post-acute (lasting ≥2 months) COVID-19 sequelae.

RESULTS

A total of 1443 COVID-19 survivors and 2962 non-COVID-19 controls were included. Of the COVID-19 survivors, >80% and >40% self-reported acute and post-acute COVID-19 sequelae, respectively. In the post-acute phase, COVID-19 survivors who were physically inactive had a 37% lower risk of insomnia, whereas those with prolonged sedentary behavior had 25%, 67%, and 117% higher risks of at least one symptom, dizziness, and "pins and needles" sensation, respectively. For the acute phase, prolonged sedentary behavior was associated with a higher risk of fatigue, "brain fog," dyspnea, muscle pain, joint pain, dizziness, and "pins and needles" sensation. Notably, sedentary behavior, rather than physical inactivity, was correlated with a higher risk of severe post-COVID-19 sequelae in both acute and post-acute phases.

CONCLUSIONS

Prolonged sedentary behavior was independently associated with a higher risk of both acute and post-acute COVID-19 sequelae, whereas physical inactivity played contradictory roles in COVID-19 sequelae.

The causal relationship between risk of developing bronchial asthma and frailty: a bidirectional two-sample Mendelian randomization study

Background

A potential link between asthma and frailty has been suggested in previous studies. However, the nature of the causal relationship between these two conditions warrants further investigation. Therefore, this study assessed the bidirectional causality between asthma and frailty risk using two-sample Mendelian randomization (MR).

Methods

The study data were obtained from the genome-wide association study (GWAS) dataset, with 337,159 samples representing asthma data and 175,226 samples representing frailty. The causal relationship between the two disorders was assessed by selecting the single nucleotide polymorphisms (SNPs), significantly associated with both asthma and frailty. The inverse variance weighting (IVW) method was used as the main analytical method to estimate the possible influence of causality. Sensitivity analysis was also performed using Mr-Egger intercept, funnel plot, "leave-one-out," and Cochran Q test. In addition, potential mediators were investigated by risk factor analysis.

Result

The IVW method showed an increased risk of frailty due to increased genetic susceptibility factors and the number of to asthma (OR = 2.325, 95%CI:1.958-2.761; p = 6.527498e-22), while no horizontal pleiotropy was observed for the Mr-Egger intercept (p = 0.609) and the funnel plot. The Cochran Q value was 72.858, p = 0.024, and there was heterogeneity in the Cochran Q-value. No single SNP was observed for "leave-one-out" that had a biasing effect on the instrumental variables. In addition, genetic susceptibility to frailty was associated with asthma (OR = 1.088, 95%CI:1.058-1.119; p = 4.815589e-09). In the causal relationship described above, several risk factors for frailty are complex, with asthma leading to a significant reduction in physical activity endurance.

Conclusion

Our findings suggest a probable positive causal effect of asthma on the risk of developing frailty, potentially mediated by reduced physical activity endurance. At the same time, a causal relationship exists between frailty and asthma. Therefore, assessment strategies for frailty should include asthma and vice versa.

Sex hormone-binding globulin exerts sex-related causal effects on lower extremity varicose veins: evidence from gender-stratified Mendelian randomization

Background

The association between serum sex hormones and lower extremity varicose veins has been reported in observational studies. However, it is unclear whether the association reflects a causal relationship. Besides, serum sex hormone-binding globulin (SHBG) has been rarely studied in lower extremity varicose veins. Here, we aim to investigate the association between serum levels of SHBG, testosterone, and estradiol and the risk of lower extremity varicose veins using Mendelian randomization (MR).

Methods

We obtained genome-wide association study summary statistics for serum SHBG levels with 369,002 European participants, serum testosterone levels with 424,907 European participants, serum estradiol levels with 361,194 European participants, and lower extremity varicose veins with 207,055 European participants. First, a univariable MR was performed to identify the causality from SHBG and sex hormone levels to lower extremity varicose veins with several sensitivity analyses being performed. Then, a multivariable MR (MVMR) was performed to further assess whether the causal effects were independent. Finally, we performed a gender-stratified MR to understand the role of genders on lower extremity varicose veins.

Results

Genetically predicted higher serum SHBG levels significantly increased the risk of lower extremity varicose veins in the univariable MR analysis (OR=1.39; 95% CI: 1.13-1.70; P=1.58×10-3). Sensitivity analyses and MVMR (OR=1.50; 95% CI:1.13-1.99; P=5.61×10-3) verified the robustness of the causal relationships. Gender-stratified MR revealed that higher serum SHBG levels were associated with lower extremity varicose veins in both sexes. However, the OR of serum SHBG levels on lower extremity varicose veins risk in females (OR=1.51; 95% CI: 1.23-1.87; P=1.00×10-4) was greater than in males (OR=1.26; 95% CI: 1.04-1.54; P=1.86×10-2).

Conclusions

Serum SHBG levels are positively related to lower extremity varicose veins risk in both sexes, especially in females. This may partly explain the higher prevalence of varicose vines among females.

Exploring the association between air pollution and Parkinson's disease or Alzheimer's disease: a Mendelian randomization study

The correlation between air pollution and neurodegenerative diseases has garnered growing attention. Although observational studies have indicated a potential link between air pollution and neurodegenerative disease, establishing a causal relationship remains uncertain. To address this gap, we performed a two-sample Mendelian randomization analysis utilizing genetic instruments. This analysis aimed to investigate the causal connections between PM2.5, PM10, NO2, and NOX exposure and the occurrence of Parkinson's disease (PD) and Alzheimer's disease (AD). We implemented a series of filtering steps to identify suitable genetic instruments that demonstrated significant associations (P < 5 × 10-8) with PM2.5, PM10, NO2, and NOX. These instruments were derived from a comprehensive genome-wide association study (GWAS) encompassing up to 456,380 participants in the UK Biobank. To obtain summary statistics for PD (N = 482,730) and AD risk (N = 63,926), we utilized the most recent GWAS datasets available. For our primary analysis, we employed the inverse-variance weighted approach for two-sample MR. A multivariable MR (MVMR) was also performed to verify the impact of air pollution exposure on the risk of PD and AD. To ensure the robustness of our findings, sensitivity analyses and heterogeneity assessments were performed. In two-sample MR, by employing the inverse-variance weighted method, our result suggested that genetically NO2 exposure showed a significant association with an elevated risk of PD (OR = 4.07, 95% CI: 1.13 to 19.62, P = 0.034) and genetically PM10 exposure exhibited a significant association with a heightened risk of AD (OR = 1.93, 95% CI: 1.03-3.59, P = 0.040). Further MVMR analysis demonstrated that the causal effect between NO2 and PD disappeared (OR = 3.489, 95% CI: 0.01 to 2.1e + 03, P = 0.703), and only PM10 was associated with an increased risk of AD (OR = 6.500, 95% CI: 1.10 to 38.51, P = 0.039). Sensitivity analysis showed no detectable heterogeneity and pleiotropy (P > 0.05). Our findings demonstrate that NO2 and PM10 exposure may contribute to a risk of PD and AD, respectively. Future research is necessary to elucidate potential physiopathological mechanisms.

Appraising the causal relationship between thyroid function and rheumatoid arthritis: a two-sample bidirectional Mendelian randomization study

Background

Hypothyroidism and hyperthyroidism are observationally associated with rheumatoid arthritis (RA), but causality is unclear. To evaluate the causal relationship between thyroid function and RA, we conducted a two-Sample bidirectional Mendelian Randomization (MR) study.

Methods

Single nucleotide polymorphisms associated with six phenotypes were selected from the FinnGen biobank database, The ThyroidOmics Consortium database, and the IEU Open GWAS database. For the forward MR analysis, we selected hypothyroidism (N=213,390), Graves' disease (GD) (N=199,034), other types of hyperthyroidism (N=190,799), free thyroxine (FT4, N=49,269), and thyroid-stimulating hormone (TSH, N=54,288) as the five related thyroid function phenotypes for exposure, with RA (N=58,284) as the outcome. Reverse MR analysis selected RA as the exposure and five phenotypes of thyroid function as the outcome. The Inverse variance weighting (IVW) method was used as the primary analysis method, supplemented by weighted median (WM) and MR-Egger methods. Cochran's Q test, MR-PRESSO, MR-Egger regression methods, and leave-one-out analysis were employed to assess sensitivity and pleiotropy.

Results

Forward MR evidence indicates that genetic susceptibility to hypothyroidism is associated with an increased risk of RA (ORIvw=1.758, P=7.61×10-5). Reverse MR evidence suggests that genetic susceptibility to RA is associated with an increased risk of hypothyroidism (ORIvw=1.274, P=3.88×10-20), GD (ORIvw=1.269, P=8.15×10-05), and other types of hyperthyroidism (ORIvw=1.141, P=1.80×10-03). There is no evidence to support a forward or reverse causal relationship between genetic susceptibility to RA and FT4, TSH.

Conclusion

Our results provide genetic evidence supporting bidirectional causal relationships between thyroid function and RA. These findings inform preventive strategies and interventions targeting RA and thyroid dysfunction.