Associations Between Body Roundness Index and Cardiovascular Outcomes: A China Kadoorie Biobank Prospective Cohort Study.

Background: Obesity traditionally scaled by body mass index, and visceral fat are independent risk factors for cardiovascular diseases (CVDs). Assessing obesity's impact on CVDs based solely on height or weight can be inaccurate. The body roundness index (BRI) estimates visceral fat distribution, but its association with CVDs in large-scale Chinese cohort remained unexplored.

Objectives: This study sought to investigate the association between BRI and cardiovascular outcome in the general Chinese population.

Methods: In a prospective cohort of 488,656 CKD (China Kadoorie Biobank) participants free of CVDs, multivariable Cox proportional hazard models were employed to investigate the association between BRI and a composite outcome of coronary heart disease (CHD), heart failure (HF), stroke, and cardiovascular death. The mediation effect of hypertension and diabetes in the BRI-CVD association was further explored.

Results: During a median follow-up of 10.2 years (Q1-Q3: 9.2-11.3 years), 76,891 of 488,656 cases (15.7%) of composite outcome were documented. Compared to the lowest BRI quartile, participants in the highest quartile exhibited significantly increased hazards of composite outcomes (HR: 1.37; 95% CI: 1.34-1.40), CHD (HR: 1.52; 95% CI: 1.47-1.57), HF (HR: 1.24; 95% CI: 1.13-1.37), and stroke (HR: 1.41; 95% CI: 1.37-1.46). Restricted cubic spline analysis demonstrated J-shaped dose-response associations between BRI and composite outcome or CHD, whereas the BRI-HF and BRI-cardiovascular death associations were U-shaped. Both hypertension and diabetes mediated the BRI-CVD association, with a mediation proportion of 14.2% (95% CI: 13.2%-15.0%) and 1.7% (95% CI: 1.4%-2.0%), respectively.

Conclusions: In the CKB cohort, BRI was positively significantly associated with cardiovascular outcome. Hypertension could be a potential mediator in the BRI-CVD association.