High triglyceride-glucose index is associated with diabetes mellitus in people with HIV in Southwest China: a 13-year retrospective longitudinal cohort study

Background: The triglyceride-glucose (TyG) index, an emerging marker of insulin resistance, has shown promise in predicting various non-communicable diseases. This study investigated the association between the TyG index and the incidence of type 2 diabetes mellitus (T2DM) within a 13-year retrospective longitudinal cohort of people with HIV (PWH). Methods: This retrospective cohort study utilized data from the China National Free ART Program (CNFAP) in Guangxi, enrolling PWH who initiated ART between 2010 and 2022. The primary exposure, TyG index, was calculated as ln [TG(mg/dL) × FBG(mg/dL)/2]. The outcome, T2DM, was defined as two consecutive FBG measurements ≥7 mmol/L. Gaussian mixture model (GMM)-based multi-trajectory analysis identified TyG trajectories. Multivariate Cox proportional hazards models were used to estimate the associations between TyG trajectories and the risk of T2DM. Results: A total of 15,370 patients were included, with 69.9% male, and a median age of 45 at ART initiation. Over 63,232 person-years of follow-up, 22.7% (3493/15370) developed T2DM.The “high Inverted U-shape” TyG trajectory was significantly associated with T2DM (aHR: 2.37, 95% CI: 2.21–2.54). Additionally, the TyG index outperformed FBG in predicting T2DM at both 5 and 10 years (5-year AUC: 0.640 vs. 0.621, P = 0.003; 10-year AUC: 0.655 vs. 0.592, P < 0.001). Conclusions: This study highlights the clinical value of the TyG index as a predictive marker for T2DM in PWH, suggesting its potential for early risk stratification.