Hemorrhoids and cardiovascular disease: A bidirectional Mendelian randomization study.

Background: Emerging evidence suggests that hemorrhoids are associated with cardiovascular disease (CVD). However, the causal associations between hemorrhoids and CVD remain elusive. This study aimed to investigate potential causal links between hemorrhoids and various heart conditions, including arrhythmia, heart failure, myocardial infarction, atrial fibrillation, and coronary artery disease.

Methods: A two-sample bidirectional Mendelian randomization (MR) analysis was conducted using summary statistics of hemorrhoids and CVD from publicly available genome-wide association studies (GWAS). The MR analyses utilized inverse-variance weighted, weighted median, weighted mode, and MR-Egger methods. Sensitivity analyses included Cochran's Q test, MR-Egger regression, MR pleiotropy residual sum and outlier (MR-PRESSO), and leave-one-out analysis. A radial MR analysis was performed after excluding outliers.

Results: Genetically determined hemorrhoids did not exhibit a causal effect on arrhythmia (OR = 0.9998, P = 0.83), heart failure (OR = 0.94, P = 0.14), myocardial infarction (OR = 0.94, P = 0.27), atrial fibrillation (OR = 0.98, P = 0.55), or coronary artery disease (OR = 0.99, P = 0.84). The reverse analysis yielded similar results. Consistent results were observed with alternative MR methods, and the absence of significant heterogeneity was confirmed. The radial MR analyses support the conclusions in the forward and reverse analyses.

Conclusions: This bidirectional MR analysis did not find statistical causal association between hemorrhoids and CVD, suggesting the possibility of shared risk factors such as obesity and diet. Further prevention strategies for CVD could focus on the management of common risk factors.