Obesity and physical inactivity are associated with increased risks of cardiac conduction disease: a report from the Kailuan Cohort Study

Physical activity (PA) and obesity may alter the risks of cardiac conduction disease. Participants from the Kailuan cohort, who were free of cardiac conduction disease and with repeated measurements of electrocardiogram from 2006 to 2019, were included. The primary outcome was cardiac conduction disease. The secondary outcomes were atrioventricular block and intraventricular block. Cox regression was used to assess the association between obesity, PA, and the risks of the outcomes. Influences of PA on the associations between BMI and incident outcomes were evaluated. A total of 84,022 participants (mean age 50.15 years, SD 11.69; 80.3% male) were included. Over a median follow-up of 11.83 years (IQR 8.87–13.04), 3236 participants developed the primary outcome. After multivariable adjustment, a higher body mass index (BMI) and a higher waist circumference (WC) were associated with increased risks of conduction disease, but more PA was associated with a lower risk. For obese patients defined by BMI with low PA, the risk of conduction disease was higher than that of obese patients with high PA (HR: 1.42, CI: 1.21-1.66 vs. HR: 1.16, CI: 1.03–1.31). For central obese patients defined by WC with low PA, the risk of conduction disease was also higher compared to central obese patients with high PA (HR: 1.31, CI: 1.17–1.48 vs. HR: 1.12, CI: 1.03–1.23). Besides, compared to obesity with high PA, obesity with low PA was associated with a higher risk of atrioventricular block (HR: 1.70, CI: 1.28-2.27 vs. HR: 1.45, CI: 1.16-1.81) and intraventricular block (HR: 1.37, CI: 1.13-1.65 vs. HR: 1.03, CI: 0.92–1.15). Higher PA can reduce the risks of developing cardiac conduction disease, both in the obese and non-obese groups. (Clinical Trial Registration URL: https://www.chictr.org . Unique identifier: ChiCTRTNC-11001489).