Glomerular Hyperfiltration as an Independent Predictor of All-Cause Mortality in Healthy Adults: A Nationally...

Glomerular hyperfiltration (GHF) is a marker of systemic dysfunction, but its link to long-term mortality in healthy adults remains unclear.

This nationally representative cohort study included 14,309 healthy adults from the National Health and Nutrition Examination Survey. GHF was defined as age- and sex-specific estimated glomerular filtration rate (eGFR) indexed for individual body surface area (BSA) exceeding the 95th percentile. Normal filtration was defined as the 25th-75th percentile. All-cause mortality risk was assessed using Cox proportional hazards models, propensity score matching, and restricted cubic spline regression.

Among participants, 722 exhibited GHF (median eGFR: 168 mL/min/BSA m2) and 7,153 had normal filtration (median eGFR: 115 mL/min/BSA m2). Over a median follow-up of 123 months, GHF was associated with increased mortality risk (fully adjusted hazard ratio [HR]: 1.86; 95% confidence interval [CI]: 1.33, 2.60). Propensity score-matched analysis yielded consistent results (HR: 2.60; 95% CI: 1.25, 5.39). Restricted cubic splines revealed a U-shaped eGFR-mortality relationship, with risk progressively increasing above the 60th eGFR percentile. Sensitivity analyses confirmed the robustness of these findings across various stratification methods and exclusion criteria.

GHF independently predicts increased mortality in healthy adults, suggesting its potential role as a systemic risk marker and highlighting the potential value of revisiting kidney health assessment frameworks.