Association of cardiovascular risk factors and lifestyle behaviors with aortic aneurysm: A Mendelian randomization study

The causal relationship between smoking and thoracic aortic aneurysm: Evidence from Mendelian randomization analysis

The potential role of smoking as a risk factor for thoracic aortic aneurysm is still a subject of debate. Therefore, it is important to systematically investigate the causal relationship between smoking and thoracic aortic aneurysm using Mendelian randomization methods. Genetic data were obtained from genome-wide association studies using the inverse variance weighting method as the primary approach. A thorough sensitivity analysis was conducted to ensure the reliability of the findings. Instrumental variables were assessed using the F statistic, and meta-analysis was employed to assess the average genetic predictive effect between smoking and thoracic aortic aneurysm. Our Mendelian randomization study found a positive association between smoking and thoracic aortic aneurysm. The odds ratios (OR) in the inverse variance weighting method were OR = 1.23 (95% confidence interval [CI] = 1.00-1.51; P = .053) and OR = 2.07 (95% CI = 1.10-3.91; P = .024). Furthermore, meta-analyses consistently demonstrated a positive causal relationship between ferritin and myocardial infarction, although statistical significance was not observed. The analysis results did not indicate any horizontal pleiotropy. Despite the presence of heterogeneity, the Mendelian randomization analysis still yielded significant results. This study employed Mendelian randomization to establish a positive association between smoking levels and the risk of thoracic aortic aneurysm. The genetic evidence reveals a causal relationship between the two, offering new insights for future interventions targeting thoracic aortic aneurysms.

Alcohol Exposure and Disease Associations: A Mendelian Randomization and Meta-Analysis on Weekly Consumption and Problematic Drinking

Alcohol consumption significantly impacts disease burden and has been linked to various diseases in observational studies. However, comprehensive meta-analyses using Mendelian randomization (MR) to examine drinking patterns are limited. We aimed to evaluate the health risks of alcohol use by integrating findings from MR studies. A thorough search was conducted for MR studies focused on alcohol exposure. We utilized two sets of instrumental variables-alcohol consumption and problematic alcohol use-and summary statistics from the FinnGen consortium R9 release to perform de novo MR analyses. Our meta-analysis encompassed 64 published and 151 de novo MR analyses across 76 distinct primary outcomes. Results show that a genetic predisposition to alcohol consumption, independent of smoking, significantly correlates with a decreased risk of Parkinson's disease, prostate hyperplasia, and rheumatoid arthritis. It was also associated with an increased risk of chronic pancreatitis, colorectal cancer, and head and neck cancers. Additionally, a genetic predisposition to problematic alcohol use is strongly associated with increased risks of alcoholic liver disease, cirrhosis, both acute and chronic pancreatitis, and pneumonia. Evidence from our MR study supports the notion that alcohol consumption and problematic alcohol use are causally associated with a range of diseases, predominantly by increasing the risk.

No Causal Association Between Inguinal Hernia and Aortic Aneurysm Using Mendelian Randomization Analysis

Aortic aneurysm (AA) is a serious disease that affects the aging population worldwide. Potential risk or associated factors, such as inguinal hernia, have been suggested by conventional studies. In the present study, summary statistics data for the associations of inguinal hernia were derived from a large genome-wide association study including 18,791 inguinal hernia cases and 93,955 controls in the UK Biobank. Corresponding data of AA were extracted from FinnGen, comprising 7603 cases and 317,899 controls in Finland. The causal association was assessed using Mendelian Randomization-Egger, weighted median, and inverse variance weighting methods, and compared with observational estimates previously published. Our analysis found no convincing causal effect between genetically predicted inguinal hernia and the risk of AA (odds ratio [OR] = 1.05, 95% confidence interval [CI] = 0.85-1.31, P = .65), abdominal aortic aneurysm (AAA, OR = 1.15, 95% CI = 0.92-1.46, P = .22), and thoracic aortic aneurysm (TAA, OR = 1.05, 95% CI = 0.85-1.30, P = .67). The results are in contrast to previous observational evidence suggesting a potentially common causal association between inguinal hernia and AA. Further research is needed to better understand the interplay between risk factors and their impact on aneurysm development.

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.

The causal association between smoking initiation, alcohol and coffee consumption, and women's reproductive health: A two-sample Mendelian randomization analysis

Objective: A number of epidemiological studies have demonstrated that smoking initiation and alcohol and coffee consumption were closely related to women's reproductive health. However, there was still insufficient evidence supporting their direct causality effect. Methods: We utilized two-sample Mendelian randomization (TSMR) analysis with summary datasets from genome-wide association study (GWAS) to investigate the causal relationship between smoking initiation, alcohol and coffee consumption, and women's reproductive health-related traits. Exposure genetic instruments were used as variants significantly related to traits. The inverse-variance weighted (IVW) method was used as the main analysis approach, and we also performed MR-PRESSO, MR-Egger, weighted median, and weighted mode to supplement the sensitivity test. Then, the horizontal pleiotropy was detected by using MRE intercept and MR-PRESSO methods, and the heterogeneity was assessed using Cochran's Q statistics. Results: We found evidence that smoking women showed a significant inverse causal association with the sex hormone-binding globulin (SHBG) levels (corrected β = -0.033, p = 9.05E-06) and age at menopause (corrected β = -0.477, p = 6.60E-09) and a potential positive correlation with the total testosterone (TT) levels (corrected β = 0.033, p = 1.01E-02). In addition, there was suggestive evidence for the alcohol drinking effect on the elevated TT levels (corrected β = 0.117, p = 5.93E-03) and earlier age at menopause (corrected β = -0.502, p = 4.14E-02) among women, while coffee consumption might decrease the female SHBG levels (corrected β = -0.034, p = 1.33E-03). Conclusion: Our findings suggested that smoking in women significantly decreased their SHBG concentration, promoted earlier menopause, and possibly reduced the TT levels. Alcohol drinking had a potential effect on female higher TT levels and earlier menopause, while coffee consumption might lead to lower female SHBG levels.