Triglyceride-glucose index and admission eGFR <90 mL/min/1.73 m2 among hospitalized adults in southern China: a single-center cross-sectional study

To examine the association between the triglyceride-glucose (TyG) index and admission estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m 2 among hospitalized adults in southern China and to assess the sensitivity of this association to alternative outcome definitions and age specifications. This single-center retrospective cross-sectional study included 1707 inpatient episodes recorded in 2024. The primary operational outcome was admission eGFR < 90 mL/min/1.73 m 2 . Logistic regression models incorporated continuous age represented by a four-degree-of-freedom natural cubic spline. Sensitivity analyses examined eGFR < 60 mL/min/1.73 m 2 , three eGFR categories, continuous eGFR, modified Poisson prevalence ratios, and multiplicative interactions. Of the 1707 included episodes, 597 (35.0%) had admission eGFR < 90 mL/min/1.73 m 2 ; 441 had eGFR 60–< 90 and 156 had eGFR < 60 mL/min/1.73 m 2 . In the fully adjusted model, each one-unit increase in TyG was associated with higher odds of admission eGFR < 90 (OR, 1.39; 95% CI 1.15–1.69; P < 0.001), with a corresponding prevalence ratio of 1.15 (95% CI 1.06–1.24; P < 0.001). For eGFR < 60, the OR was 1.16 (95% CI 0.89–1.51; P = 0.280), whereas the adjusted coefficient for continuous eGFR was −0.84 mL/min/1.73 m 2 (95% CI −2.14 to 0.46; P = 0.206). The TyG-by-sex and continuous-age spline interaction tests were not statistically significant (P = 0.309 and P = 0.248, respectively). Higher TyG was associated with admission eGFR < 90 mL/min/1.73 m 2 after adjustment for measured covariates. The association was not statistically significant for eGFR < 60 or continuous eGFR, indicating that its magnitude depended on the outcome definition. Prospective studies using repeated kidney-function measurements are needed to clarify the clinical relevance of this association.