Mediation by Lipid‐Glucose Metabolic Indices in the Association Between Overweight and T2DM Among Shanghai Community‐Dwelling Older Adults

Objective This study is aimed at exploring the mediating roles of the triglyceride‐glucose (TyG) index, cholesterol‐HDL‐glucose (CHG) index, and atherogenic index of plasma (AIP) in the association between overweight and Type 2 diabetes mellitus (T2DM) among older adults in Shanghai, China. Methods A total of 44,715 participants aged ≥ 60 years from the Shanghai Non‐communicable Diseases Management Cohort were included. Overweight was defined as a body mass index (BMI) ≥ 24 kg/m 2 . T2DM was diagnosed clinically by physicians. Mediation analysis was performed to estimate direct, indirect, and total effects. Results The mean age of the participants was 77 ± 6.8 years, 16,835 (37.65%) were diagnosed with T2DM, and 27,880 (62.35%) did not. In covariate‐adjusted models, overweight older adults had a 26% higher odds of T2DM than nonoverweight older adults. The TyG, CHG, and AIP indices were all associated with T2DM. In the mediation analysis, the proportions of the total effect mediated by the TyG, CHG, and AIP indices were 22.03%, 32.24%, and 6.47%, respectively. Conclusion The lipid‐glucose metabolic indices examined, particularly CHG and TyG indices, partially mediated the association between overweight and T2DM. These biomarkers may serve as early intervention targets to prevent T2DM among overweight older adults.