Creatinine production, nutrition, and glomerular filtration rate estimation

Abstract

This study examined the validity and clinical implications of the assumption of the Modification of Diet in Renal Disease Study (MDRD) formula that age, gender, race, and BUN account for creatinine production (CP). The relationships of MDRD GFR, CP, and nutrition were examined in 1074 Dialysis Morbidity and Mortality Study Wave II patients with reported measured creatinine clearances at initiation of dialysis. Age, gender, race, BUN, and serum creatinine (Scr) were used to calculate MDRD GFR. The measured 24-h urinary creatinine was used to estimate CP. In linear regression, Scr positively correlated with CP independent of age, gender, race, and BUN. Compared with the highest CP quartile, the lowest CP quartile had lower creatinine clearance (5.8 ± 2.9 versus 11.3 ± 3.4 ml/min, P < .01) despite lower Scr (5.8 ± 2.6 versus 8.6 ± 3.1 mg%, P < .01). Malnutrition (48% versus 26%, P