日本人における糸球体濾過量 (GFR) 推算式の比較検討

Abstract

Creatinine clearance (Ccr) is widely used for the evaluation of the glomerular filtration rate (GFR). Since the clearance method requires urine collection, formulae for predicting GFR without urine collection have been developed. In the guidelines of the Kidney Disease Outcomes Quality Initiative(K/ DOQI), the formulae developed from the Modification of Diet in Renal Disease Study (MDRD) are recommended for estimating GFR. The objective of the present study is to compare measured Ccr and Ccr estimated by the Cockcroft-Gault, Horio and MDRD equations in Japanese adults. In 100 inpatients (67 men and 33 women) in this hospital, we evaluated the correlation between measured Ccr derived from 24-hour urinary collections and predicted Ccr or GFR calculated using the Cockcroft-Gault, Horio, and MDRD equations. The equation of linear regression is given as y = 0.8165x+2.1229 (r = 0.9415, p < 0.0001) by the Cockcroft-Gault formula, y = 0.7478x+1.6757 (r = 0.9458, p < 0.0001) by the Horio formula and y = 0.8335x+4.4261 (r = 0.9209, p < 0.0001) by the MDRD formula (y : measured Ccr, x : estimated Ccr or GFR). These predictive formulae demonstrated a strong correlation. Although the Cockcroft-Gault formula derived from Japanese patients demonstrated the highest correlation with Ccr, both the Horio formula and the MDRD formula also showed a high correlation. These predictive formulae could be useful for the prediction of Ccr in Japanese patients.