Association Between Cumulative Body Mass Index Exposure and the Risk of Incident Cardiac Conduction Block

Background The relationship between cumulative body mass index (cumBMI) exposure and cardiac conduction block (CCB) is not fully understood. This study aimed to explore the association between cumBMI and the risk of CCB. Methods and Results A total of 107 860 participants of the Kailuan Study were included. Participants were then categorized into 4 groups based on their quartile of cumBMI. The association of cumBMI with CCB was estimated using the Cox proportional hazards regression model. During a median follow‐up of 8.36 years, 1894 CCBs, 586 atrioventricular blocks (AVBs), 1273 intraventricular blocks, 851 right bundle branch blocks, and 319 any left bundle branch blocks occurred. After adjusting for potential confounders, the hazard ratios for CCB, atrioventricular block, intraventricular block, right bundle branch block, and any left bundle branch block were 1.86 (95% CI, 1.60–2.18), 2.51 (95% CI, 1.90–3.32), 1.55 (95% CI, 1.28–1.87), 2.14 (95% CI, 1.69–2.71), and 1.18 (95% CI, 0.81–1.72) for individuals in the highest quartile of cumBMI compared with those in the second quartile, respectively. Additionally, the subgroup analyses showed significant interactions between age, sex, and cumBMI for developing CCB ( P for interaction<0.05). Conclusions Our findings suggest that higher cumulative BMI exposure significantly increased the risk of CCB, especially atrioventricular block. Monitoring cumulative BMI may help to identify high‐risk CCB populations.