The nonlinear association between Body Roundness Index and left ventricular diastolic dysfunction in type 2 diabetes

Background Left ventricular diastolic dysfunction (LVDD) is a common complication of type 2 diabetes (T2DM), closely associated with obesity and visceral adiposity. The Body Roundness Index (BRI) is a novel anthropometric measure that may better reflect visceral fat distribution, yet its relationship with LVDD in T2DM remains unclear. Objective This study aims to investigate the association between BRI and LVDD risk in patients with T2DM, focusing on nonlinear relationships and potential threshold effects. Methods This cross-sectional study included 1,317 patients with T2DM. Multivariable logistic regression and generalized additive models (GAM) were used to assess associations, with adjustment for key confounders. Threshold effects were evaluated using a two-step recursive approach, and subgroup analyses were performed. Results After full adjustment, each one-unit increase in BRI was associated with a 30% higher risk of LVDD (OR: 1.30, 95% CI: 1.10–1.60, p < 0.001). A nonlinear relationship was identified with an inflection point at BRI = 8.1. Below this point, the association was stronger (OR: 1.50, 95% CI: 1.20–1.80, P < 0.001). Diabetic kidney disease significantly modified this association ( P for interaction = 0.02). Conclusion BRI is nonlinearly associated with LVDD risk in T2DM, with a threshold effect at BRI = 8.1. The association is stronger in patients with diabetic kidney disease, suggesting that BRI could serve as a valuable marker for the stratification and prevention of LVDD in high-risk populations.