Lean Mass Index Adjustment of eGFR Strengthens Associations with Cardiometabolic Risk Factors

Background/Objectives: Serum creatinine (SCr)-based estimates of glomerular filtration rate (eGFRSCr) are influenced by muscle mass. This study investigated whether normalizing SCr to dual-energy X-ray absorptiometry (DEXA)-derived lean mass index (LMI) alters associations with cardiometabolic phenotypes.

Methods

We analyzed 11,141 adults (mean age 46.0 ± 17.2 years) from the Austrian LEAD (Lung, hEart, sociAl, boDy) cohort. SCr was normalized to sex- and age-specific LMI reference values to calculate LMI-adjusted eGFR (eGFRLMISCr) within individuals. Associations with prevalent cardiometabolic conditions were compared using age- and sex-adjusted logistic regression with paired bootstrap resampling. Annualized eGFR change was compared in 7487 participants with complete follow-up measurements.