Association of Longitudinal Trajectory of Body Roundness Index With CVD Risk: Evidence From a Multicohort Study.

Objective: This study aimed to characterize the longitudinal trajectory of the body roundness index (BRI) in a multinational cohort and to investigate its association with cardiovascular disease (CVD) events.

Methods: We pooled individual-level data from three prospective cohort studies across the United States, the United Kingdom, and China, covering 2004 to 2019. The trajectory of BRI was determined using latent class growth mixed models, and the relationship between BRI trajectory and CVD risk was evaluated using Cox models.

Results: Three longitudinal BRI trajectories were characterized: inverse-U (7.2%), low-increasing (44.4%), and middle-increasing (48.4%). The risk of CVD in the middle-increasing group and the inverse-U group was 1.25 times (95% CI: 1.12-1.35) and 1.86 times (1.53-2.36) higher than that in the low-increasing group, respectively. The historical maximum BRI, area under the curve, and time-weighted BRI all showed a nonlinear risk of CVD in the dose-response relationship (p < 0.05). The effect of BRI growth rate on CVD decreased with age.

Conclusions: The BRI trajectories were significantly associated with CVD risk, independent of baseline BRI and BMI. This emphasizes the long-term and persistent effects of visceral fat accumulation and may provide a reference for personalized CVD risk assessment and early impact.