Every one-grade increase in body roundness index doubles the risk of postmenopausal cardiometabolic multimorbidity: a CHARLS-based cohort study and its implications for public health screening

Cardiometabolic multimorbidity (CMM) is associated with severe health outcomes; menopause is an independent risk factor for cardiovascular disease in women, and the risk of central obesity is also increased during this phase. Body roundness index (BRI) can effectively reflect visceral obesity. This study aims to investigate the of strength association between cumulative exposure to BRI and CMM risk in postmenopausal Chinese women, and to evaluate the potential of cumulative (cuBRI) as a long-term risk marker and a simple screening tool for CMM.

Based on data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2020, 3780 postmenopausal women were enrolled as study participants. Multivariate logistic regression models were used to analyze the association of cuBRI and BRI trajectories with CMM risk; restricted cubic splines (RCS) curves were employed to examine the dose-response relationship; subgroup analyses were conducted to determine effect modification, and Bonferroni and false discovery rate (FDR) corrections were applied to control false positives. ROC curves were plotted to compare the predictive performance of cuBRI with that of BMI.

The fully adjusted model showed that for every 1-interquartile range (IQR) increase in cuBRI, the risk of CMM increased by 112.4% (OR=2.124, 95%CI: 1.901 to 2.373, P<0.001); compared with the lowest cuBRI IQR group, the risk of CMM was significantly higher in the highest cuBRI IQR group (OR=4.701, 95%CI: 3.661 to 6.081, P<0.001). Results from stepwise logistic regression further confirmed that cuBRI, BMI, age, dyslipidemia, kidney disease, depression scores, and C-reactive protein (CRP) were independent risk factors for CMM (all P<0.01). RCS analysis further demonstrated a linear positive correlation between cuBRI and CMM risk (P_overall<0.001, P_nonlinear=0.224). When cuBBI>18.346, CMM risk shows a significant and sustained upward trend. ROC curve analysis indicated that cuBRI (AUC=0.742) showed a predictive performance for CMM comparable to that of BMI (AUC=0.747). Subgroup analyses revealed that, after FDR and Bonferroni corrections, the positive association between cuBRI and CMM remained robust in the following subgroups: those aged 45 to <60 years, those aged ≥60 years, those without dyslipidemia, those without kidney disease, those with a score of center for epidemiologic studies depression scale (CES-D) <10, and BMI of 18.5 to <24.0 kg/m² (all P_Bonferroni<0.05).

Elevated cuBRI levels are significantly and positively associated with the risk of CMM in postmenopausal Chinese women, and their predictive performance is comparable to that of BMI, suggesting that it may help reflect long-term central obesity burden, and can be used to identify high-risk populations for CMM.

Under the framework of “Healthy China 2030” initiative and the national framework for basic public health services, it is recommended that cuBRI be incorporated into primary-care follow-up protocols for postmenopausal women to identify high-risk populations (cuBRI >18.346), and to implement lifestyle interventions and comprehensive management of metabolic indicators. The combined application of cuBRI and BMI may optimize risk stratification, and its causal effects and optimal cutoff point require validation through intervention studies.