Abstract
This study aimed to evaluate the causal effects of inflammatory bowel disease (IBD) and erectile dysfunction (ED) using Mendelian randomization (MR). All datasets were obtained from the public genome-wide association study database. In the exposure group, 12,882 IBD patients and 21,770 controls were included. A total of 1154 ED patients and 94,024 controls were included in the outcome group. Two-sample MR was conducted to estimate the causal effect of IBD on ED. Furthermore, Crohn's disease (CD) and ulcerative colitis (UC) were exposure factors in subgroup analyses. Weighted median, MR-egger, Inverse-variant weighted (IVW), weighted mode, and simple mode methods were used in MR analysis. Horizontal pleiotropy test, heterogeneity test, and leave-one-out method were utilized to evaluate the sensitivity and stability of results. After analysis, 62, 52, and 36 single nucleotide polymorphisms (SNPs) that IBD-ED, CD-ED, and UC-ED were included, respectively. The incidence of ED was increased by IBD (IVW: OR = 1.110, 95% CI = 1.017-1.211, P = 0.019; P-heterogeneity > 0.05) and, in addition, ED was affected by CD (IVW: OR = 1.085, 95% CI = 1.015-1.160, P = 0.016; P-heterogeneity > 0.05). However, there was no causal effect of UC on ED (IVW: OR = 1.018, 95% CI = 0.917-1.129, P = 0.743; P-heterogeneity < 0.05). All SNPs showed no significant horizontal pleiotropy (P > 0.05). These results indicate that IBD and CD can cause ED; However, UC did not cause ED. Additional research was required to determine causality and potential mechanisms further.