Association between the triglyceride-glucose index and risk of type 2 diabetes mellitus and the mediating effect of BMI: a comparative analysis in Chinese and Japanese populations

Higher baseline TyG was associated with incident T2DM in both Chinese and Japanese adults, with BMI partially mediating the TyG-diabetes association. These findings suggest that TyG captures triglyceride-glucose dysregulation beyond overall adiposity, with population-specific differences in metabolic pathways. The identification of nonlinear patterns underscores the need for population-tailored risk stratification based on TyG.