TyG index is associated with microalbuminuria in a large population-based study: independent and exploratory interaction analyses

Background Insulin resistance surrogates are associated with microalbuminuria; however, population-scale evidence for the triglyceride–glucose (TyG) index remains scarce. We examined the cross-sectional association between TyG index and microalbuminuria in a large Chinese cohort and explored whether diabetes modifies this link. Methods We analyzed 33,416 adults from eight regional centers. Microalbuminuria was defined as urinary albumin-to-creatinine ratio ≥ 30 mg/g. Multivariate logistic regression and restricted cubic splines were used to estimate odds ratios (ORs) per 1-unit TyG increase and the potential nonlinear relationship between TyG index and microalbuminuria risk. The effects of diabetes and other factors were tested using interaction terms. Results The mean age was 57.7 ± 9.3 years, and the microalbuminuria prevalence was 14.5%. TyG index was independently associated with microalbuminuria after adjustment for age, sex, body mass index, waist, hip circumference, blood pressure, lipids, liver function indices, sleep variables, estimated glomerular filtration rate, smoking, alcohol, and diabetes (OR, 1.28; 95% confidence interval [CI], 1.20–1.36; P < 0.001). Restricted cubic spline analysis demonstrated a linear association between TyG index and the odds of microalbuminuria ( P for overall association < 0.001; P for non-linearity = 0.187). The association was present in participants with (OR, 1.46; 95% CI, 1.32–1.60) and without diabetes (OR, 1.13; 95% CI, 1.04–1.23). The interaction with diabetes status was significant ( P < 0.001; false discovery rate-corrected P = 0.008), indicating a stronger association in patients with diabetes. The sensitivity analyses confirmed the robustness of the main findings. Conclusions The TyG index was linearly associated with microalbuminuria. This association was observed in patients with and without diabetes, with a stronger estimated effect among those with diabetes. TyG may serve as a simple, readily available marker for identifying individuals with higher odds of microalbuminuria across glycemic status; however, longitudinal studies are needed to establish temporal relationships.