Association of the triglyceride-glucose index with the comorbidity of bone mass abnormality and dyslipidemia: a cross-sectional study

The triglyceride-glucose (TyG) index, a simple marker of insulin resistance, is widely used in metabolic research, but its association with comorbidity of bone mass abnormality and dyslipidemia remains unclear. This cross-sectional study included 928 participants. Bone mass abnormality and dyslipidemia were assessed according to standardized criteria. Multivariate logistic regression, restricted cubic spline (RCS) analysis, saturation effect analysis, receiver operating characteristic (ROC) curves, and the DeLong test were employed to evaluate the association between the TyG index and the comorbidity condition. After adjusting for confounding factors, the TyG index remained independently and significantly positively correlated with the comorbidity (OR = 6.64, 95% CI: 3.92–11.53, P < 0.001). RCS analysis revealed a nonlinear J-shaped association between the TyG index and the risk of comorbidity ( P for non-linearity<0.001), relatively lower-risk region. Saturation effect analysis suggested a possible threshold at TyG = 9.36. ROC analysis demonstrated that the TyG index had the highest observed AUC among the evaluated indices for the comorbidity (AUC = 0.732, 95% CI: 0.685–0.780) and the DeLong test confirmed that its AUC was significantly higher than that of the combined TyG-BMI index (AUC difference = 0.1703, P < 0.001). The TyG index is independently associated with comorbidity of bone mass abnormality and dyslipidemia in a nonlinear J-shaped manner. It demonstrated the highest observed AUC among the evaluated indices and may serve as a low-cost, readily available marker for population risk stratification; however, prospective validation is required before clinical screening use can be recommended, particularly in moderate-altitude populations with unique metabolic characteristics.