Association between body roundness index and incidence of type 2 diabetes in a population-based cohort study

There is limited national data on the association between body roundness index (BRI) and type 2 diabetes (T2D). A total of 10,785 participants from the China Health and Retirement Longitudinal Study (CHARLS) with repeated BRI measurements from 2011 to 2020 were included. We used Cox proportional hazards model and restricted cubic splines (RCS) to examine the association between BRI and T2D. During a mean follow-up of 7.72 years, 1,653 incident T2D cases were documented. Multivariable Cox proportional hazards regression model demonstrated a significant correlation between the BRI and the risk of T2D. Specifically, every 1-SD increase in BRI corresponded to a 27% heightened risk of T2D (HR: 1.27, 95% CI 1.20-1.35). The analysis also uncovered a non-linear pattern in this relationship, pinpointed by an inflection point at a BRI value of 3.96. Before the inflection point, the HR was 0.85 (95% CI 0.74-0.96), while after the inflection point, the HR increased to 1.29 (95% CI 1.18-1.41). In the middle-aged and elderly Chinese population, elevated BRI was significantly and positively associated with T2D risk. BRI could be a valuable addition to current clinical and public health strategies aimed at reducing the burden of T2D.