Association between the triglyceride–high-density lipoprotein–glucose–body index and low eGFR in older Chinese adults

The triglyceride–high-density lipoprotein–glucose–body (TyHGB) index is an emerging indicator of metabolic dysfunction. We aimed to examine its relationship with reduced kidney function among older Chinese individuals (≥ 65 years). This cross-sectional study included 9231 older adults who underwent annual health examinations at the Kunshan Jinxi People’s Hospital. Reduced kidney function was defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m 2 using the 2021 CKD-EPI equation (low eGFR). Multivariable logistic regression, restricted cubic splines, subgroup analyses, and receiver operating characteristic (ROC) curves were employed. The TyHGB index was significantly higher in participants with reduced kidney function. In fully adjusted models, individuals in the highest TyHGB quartile had higher odds of low eGFR than those in the lowest quartile (OR = 1.866, 95% CI 1.436–2.425; P < 0.001). Restricted cubic spline analysis revealed a nonlinear dose–response relationship, with a threshold of 13.40. Subgroup analyses indicated a stronger association among participants without hypertension. ROC analysis indicated that the TyHGB index showed moderate discriminatory performance. The TyHGB index is a metabolic marker associated with low eGFR in older adults. The cross-sectional design precludes causal inference.