Longitudinal trajectories of the TyG-ABSI Index and subsequent risk of type 2 diabetes mellitus in a Chinese middle-aged and older cohort

BACKGROUND: the triglyceride-glucose-body shape index (TyG-ABSI) reflects insulin resistance and visceral adiposity. However, the association between its longitudinal changes and type 2 diabetes (T2DM) risk remains unclear. This study examined TyG-ABSI trajectories and incident T2DM. METHODS: data from the China Health and Retirement Longitudinal Study (CHARLS) included adults ≥ 45 years with complete metabolic and anthropometric data from Wave 1 (2011-2012) and Wave 3 (2015). Latent Profile Analysis identified TyG-ABSI trajectories. Cox models and restricted cubic splines assessed associations. RESULTS: among 4,769 participants, 943 developed T2DM over 8.05 years. Four trajectories were identified: low-stable, low-rising, medium-stable, and medium-declining. Compared with the medium-declining group, the low-rising group had the highest T2DM risk (HR 1.582, 95 % CI 1.341-1.867), followed by medium-stable (HR 1.402, 1.104-1.780), while low-stable had lower risk (HR 0.766, 0.629-0.932). Changes in TyG-ABSI showed a linear positive association with T2DM risk. Baseline TyG-ABSI was nonlinearly associated, with a threshold at 7.1. CONCLUSIONS: TyG-ABSI trajectories significantly predicted incident T2DM. Sustained increases, even from normal baseline, were linked to higher risk. Monitoring TyG-ABSI may help identify high-risk individuals for early prevention.