Cirillo M
Nefrologia, Seconda Universita' degli Studi, Napoli, Italy.
G Ital Nefrol. 2009 May-Jun;26(3):310-7.
Current guidelines suggest to evaluate kidney function by estimates of the glomerular filtration rate (GFR) calculated using the Cockcroft-Gault equation or the simplified equation of the Modification of Diet in Renal Disease (MDRD) study. Cockcroft and Gault developed a method to predict an individual's creatinine clearance without urinary data but on the basis of average creatinine clearance values corrected for age and body weight. The equation needs information about gender, age, weight, and serum creatinine. The precision of the equation is biased by overweight because the equation is based on the assumption that creatinine clearance linearly reflects body weight. The MDRD equation derives from a multiple regression used to analyze the relation of GFR measurements by a radioisotope technique over serum creatinine after data linearization by logarithm transformation and with control for gender, age, ethnicity and other variables. The equation has not been validated for GFR >60 mL/min x 1.73 m2 because the study did not include healthy persons. The two equations often give conflicting estimates of GFR. Nephrologists have to understand the rationale of the two equations for the correct interpretation of these discrepancies.
当前指南建议通过使用Cockcroft-Gault方程或肾脏疾病饮食改良（MDRD）研究的简化方程计算的肾小球滤过率（GFR）估计值来评估肾功能。Cockcroft和Gault开发了一种无需尿液数据即可预测个体肌酐清除率的方法，该方法基于根据年龄和体重校正后的平均肌酐清除率值。该方程需要性别、年龄、体重和血清肌酐的信息。由于该方程基于肌酐清除率线性反映体重的假设，因此其精度受超重影响而存在偏差。MDRD方程源自多元回归分析，该分析通过对数变换使数据线性化并控制性别、年龄、种族和其他变量后，用于分析放射性同位素技术测量的GFR与血清肌酐之间的关系。该方程尚未在GFR>60 mL/min×1.73 m²的情况下得到验证，因为该研究未纳入健康人群。这两个方程对GFR的估计值常常相互矛盾。肾病学家必须了解这两个方程的原理，以便正确解释这些差异。
