Establishment of creatinine clearance reference values for older women
Sokoll, L.J.; Russell, R.M.; Sadowski, J.A.; Morrow, F.D.
Clinical Chemistry 40(12): 2276-2281
1994
ISSN/ISBN: 0009-9147 PMID: 7988015 Document Number: 436768
Age-adjusted references ranges for creatinine clearance were determined in 279 women, ages 40-95 years, who were housed in a metabolic research unit and consumed a meat-free diet. Creatinine clearance, but not serum creatinine, declined with age by 0.63 mL/min per 1.73 m-2 per year. Serum and urine creatinine concentrations, used to calculate clearances, were analyzed by a kinetic Jaffe procedure. In a subset of 100 subjects, fasting serum creatinine values averaged 8.3 +- 5.2 (SD) mu-mol/L higher when measured by the kinetic Jaffe procedure than by an enzymatic method (creatinine PAP). The Cockcroft-Gault formula for estimating creatinine clearance from serum creatinine in women was validated, and the modification factor for the male equation was determined to be 0.84 (95% confidence interval 0.83-0.86) confirming the suggested 15% correction. A prediction formula derived from this population was similar in accuracy to the Cockcroft-Gault formula.