Diabetes modifies the association between the triglyceride-glucose index and subclinical myocardial injury: A prospective cohort study.

BACKGROUND: Triglyceride-glucose (TyG) index is considered an alternative indicator of insulin resistance and is associated with cardiovascular diseases. However, its association with subclinical myocardial injury in a general population without known cardiovascular disease has not been investigated, nor has the effect of diabetes. METHODS: Individuals without known cardiovascular disease were included from the Atherosclerosis Risk in Communities (ARIC) cohort. The baseline TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. The association between the baseline TyG index and subclinical myocardial injury [high-sensitivity cardiac troponin T (hs-cTnT≥ 14 ng/L)] was assessed using both cross-sectional and prospective cohort designs. RESULTS: A total of 11,478 participants were involved in the cross-sectional study (mean age, 56.78 years; 42.44% male) and 8801 participants were involved in the prospective cohort study (mean age, 56.57 years; 41.36% male). Both linear (r = 0.13, p < 0.001) and logistic regression analyses (adjusted odds ratio [aOR] = 1.33, p < 0.001) showed a positive association between the TyG index and baseline hs-cTnT level, which was consistent in diabetic participants (aOR = 1.64, p = 0.020) but not significant in non-diabetic participants (aOR = 0.89, p = 0.374). After a six-year follow-up, a U-shaped association between the TyG index and incidence of hs-cTnT elevation was observed among the overall participants. Further subgroup analyses showed an L-shaped (aOR = 0.72, p = 0.006) and a J-shaped (aOR = 2.09, p < 0.001) association between the TyG index and incidence of hs-cTnT elevation in participants without and with diabetes, respectively. CONCLUSION: A U-shaped association between the TyG index and the incidence of subclinical myocardial injury was observed for the first time. Diabetes may be a critical modifier of the association between the TyG index and subclinical myocardial injury. Considering the risk stratification value of the TyG index based on diabetes status may hold significant clinical value.