Ulcerative colitis increases the risk of atrioventricular block: evidence from a Mendelian randomized analysis

Although inflammatory bowel disease (IBD) has been linked to cardiovascular disease in a growing body of literature, the relationship between IBD and arrhythmia remains unclear. To investigate the causal relationship between inflammatory bowel disease and arrhythmia, we conducted this Mendelian randomization (MR) analysis. We identified single nucleotide polymorphisms (SNP) associated with IBD as instruments, including IBD, ulcerative colitis (UC), and Crohn's disease (CD). SNPs of two arrhythmia phenotypes as outcome data, namely atrioventricular block (AVB), and paroxysmal tachycardia (PTA). The inverse variance weighting method was used to analyze the two-sample Mendelian randomization with four other methods, including MR Egger, Weighted median, Simple mode, and Weighted mode. Sensitivity analysis involves different methods to detect and adjust for bias in results, including heterogeneity analysis, pleiotropy analysis, and leave-one-out sensitivity analysis. To ensure the rigor of the analysis results, we selected another set of exposure data sets and conducted the MR verification analysis using the same method. Results suggested UC is significantly associated with an increased risk of AVB (odds ratio, OR 1.178, 95% CI 1.070-1.297, P = 0.000828), the verification analysis results are consistent with this (OR 1.048, 95% CI 1.007-1.091, P = 0.022947). Our study suggests a potential risk increase of atrioventricular block in patients with UC. These results also provide further evidence that inflammatory bowel disease may increase the risk of developing arrhythmia.