Relationship between body composition and glomerular filtration rate estimates in the general population.

ABSTRACT

BACKGROUND: Differences in body composition may lead to imprecision in estimates of glomerular filtration rate (eGFR) derived from serum creatinine. Our aims were to examine the relationship between eGFR and anthropometric and body composition measures and handgrip strength. METHODS: We analyzed data from a cross-sectional study comprising 1,630 randomly selected community-dwelling adults. The Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations were used to calculate eGFR from IMDS-standardized serum creatinine. Body mass index and body surface area were calculated from measured height and weight. Body composition was determined by dual-energy x-ray absorptiometry, handgrip strength measured by a hand-held dynamometer. Regression analysis was used to examine the association between eGFR and other factors. RESULTS: In women, eGFR determined by the MDRD equation was inversely associated with height (ß = -0.08; p = 0.012), lean mass percentage (ß = -0.06; p = 0.047) and handgrip strength (ß = -0.15; p < 0.001) and eGFR calculated using the CKD-EPI equation was inversely associated with handgrip strength (ß = -0.08; p = 0.001). In men, there was an inverse association between eGFR by the MDRD equation and lean mass percentage (ß = -0.10; p = 0.013) and handgrip strength (ß = -0.12; p = 0.022) and between eGFR by the CKD-EPI equation and lean mass percentage (ß = -0.07; p = 0.018). The R(2) for these variables was <0.02. CONCLUSIONS: The inverse relationship between eGFR and measures of lean mass percentage and handgrip strength suggests that incorporation of these variables might improve eGFR prediction from serum creatinine in the general population. This effect appears to be small however and needs to be examined in studies that include measured GFR.