Body roundness index as an independent predictor for incident cardiometabolic multimorbidity in Chinese middle-aged and older adults: a large-scale longitudinal study
TL;DR
In Chinese middle-aged and older adults, an elevated BRI is an independent predictor of incident CMM, exhibiting a significant non-linear relationship and shows comparable predictive performance to BMI, suggesting its potential as a simple yet effective screening tool for early identification and targeted prevention of cardiometabolic diseases.
Abstract
Cardiometabolic multimorbidity (CMM) poses a significant public health challenge. While obesity is a key driver, the longitudinal and potentially non-linear association of the Body Roundness Index (BRI)—a novel marker of visceral adiposity—with incident CMM remains poorly understood. We aimed to prospectively evaluate the relationship between BRI and the risk of developing CMM in a large cohort of middle-aged and older Chinese adults. This prospective cohort study included 7,793 CMM-free adults aged ≥ 45 years from the China Health and Retirement Longitudinal Study (CHARLS) 2011–2018. BRI was calculated at baseline and categorized into quartiles. We employed Cox proportional hazards models to estimate hazard ratios (HRs), restricted cubic splines (RCS) to characterize the dose-response curve, and receiver operating characteristic (ROC) analysis to compare the predictive performance of BRI against Body Mass Index (BMI). We also performed sensitivity analyses to assess the robustness of our findings. During a median follow-up of 7 years, 1,935 incident CMM cases were identified. After multivariable adjustment, a clear positive association was observed. Compared to the lowest BRI quartile (Q1), the HRs for CMM were 1.21 (95% CI: 1.03–1.42) for Q2, 1.41 (95% CI: 1.19–1.66) for Q3, and 1.52 (95% CI: 1.24–1.85) for Q4. The RCS analysis revealed a significant non-linear relationship (P for non-linearity = 0.0006), where the risk increased with BRI before plateauing at very high levels. Notably, BRI showed comparable predictive accuracy to BMI for CMM (AUC: 0.627 vs. 0.617, P = 0.024), and remained significantly associated with CMM after adjusting for BMI (HR for Q4: 1.52, 95% CI: 1.24–1.85). Exploratory subgroup analyses showed that the association was more pronounced in younger adults (< 60 years), males, smokers, and alcohol consumers. In Chinese middle-aged and older adults, an elevated BRI is an independent predictor of incident CMM, exhibiting a significant non-linear relationship. BRI is independently associated with CMM risk and shows comparable predictive performance to BMI, suggesting its potential as a simple yet effective screening tool for early identification and targeted prevention of cardiometabolic diseases.