Triglyceride–glucose waist-to-height ratio improves risk stratification for depressive symptoms: evidence from NHANES

BACKGROUND: The triglyceride-glucose (TyG) index is linked to metabolic dysfunction that may contribute to depressive symptoms, but its value for population risk stratification is unclear. We aimed to examine TyG-related indices and develop an internally validated prediction model for depressive symptoms in U.S. adults. METHODS: Data were obtained from the National Health and Nutrition Examination Survey (NHANES). Survey-weighted logistic regression was used to evaluate associations between TyG-related indices, including the TyG-waist-to-height ratio (TyG-WHtR), and depressive symptoms. Predictors were selected using least absolute shrinkage and selection operator (LASSO) regression and entered into a multivariable logistic regression model to construct a nomogram. Discrimination was assessed using the area under the receiver operating characteristic curve (AUC) and internally validated using bootstrap resampling and leave-one-out cross-validation. RESULTS: Among 3,870 adults, higher TyG-related indices were associated with greater odds of depressive symptoms, with TyG-WHtR showing the strongest association [highest versus lowest tertile: odds ratio (OR) = 2.37, 95% Confidence Intervals (CI) : 1.59-3.52]. Poverty income ratio, smoking status, and TyG-WHtR were retained in the final parsimonious model, which demonstrated acceptable discrimination (AUC = 0.715) and stable internal performance after bootstrap correction (optimism-corrected AUC = 0.711). CONCLUSION: TyG-WHtR was independently associated with depressive symptoms and improved population-level risk stratification in U.S. adults. The internally validated model requires external validation before any clinical implementation.