Long-term patterns of the triglyceride-glucose index (TyG index) and their effects on cardiovascular disease (CVD) among normal-weight adults are poorly characterized. This study aimed to identify TyG index trajectories in normal-weight adults and to determine their association with the risk of incident CVD.

This study included 40,473 normal-weight participants who were free of stroke and myocardial infarction prior to or in 2012. The TyG index was calculated as ln (fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2), and the TyG index trajectories during 2006-2012 were identified by latent mixture modeling.

We identified five distinct TyG index trajectories according to TyG index range and changing pattern over time: low-stable (n = 9,806; mean TyG index 7.84-7.93), moderate-stable (n = 22,066; mean TyG index 8.43-8.52), high-decreasing (n = 1,469; mean TyG index 9.83-8.75), moderate-increasing (n = 5,842; mean TyG index 8.98-9.26), and high-stable (n = 1,290; mean TyG index 9.91-10.07). During 6.74 years of follow-up, we documented 1,577 incident CVD events. Compared with the low-stable pattern, the highest risk of CVD was observed in the high-stable pattern (hazard ratio [HR], 2.24; 95% confidence interval [CI]: 1.73-2.90), followed by the moderate-increasing pattern (HR, 1.70; 95% CI, 1.43-2.04), the high-decreasing pattern (HR, 1.45; 95% CI, 1.11-1.89), and the moderate-stable pattern (HR, 1.25; 95% CI, 1.08-1.44). Similar results were also observed for stroke and myocardial infarction.

Distinct TyG index trajectories were significantly associated differently subsequent risk of CVD in normal-weight individuals. These observations suggested that long-term trajectories of TyG index may be useful for predicting CVD among normal-weight adults.