Schwartz G J, Gauthier B
J Pediatr. 1985 Mar;106(3):522-6. doi: 10.1016/s0022-3476(85)80697-1.
We reexamined the relationship between creatinine clearance (Ccr) and body habitus in 212 girls and 356 boys, including 181 boys and 69 girls between 13 and 21 years of age. The use of formula Ccr = k L/Pcr, where k = 0.55 for the calculation of GFR, resulted in a significant underestimation of GFR in adolescent boys but was suitable for girls. In 51 adolescent boys the equation Ccr = 0.7 L/Pcr resulted in an accurate estimate of GFR. Regression analysis in 133 boys aged 3 to 21 years showed that the constant k increased gradually and linearly with age (r = 0.35, P less than 0.01). GFR could be better estimated for boys of any age by the linear bivariate equation Ccr = 1.5 (age) + 0.5 (L/Pcr), where age is given in years (r = 0.82, P less than 0.001). This equation yielded slightly better results than did 0.7 L/Pcr in 91 additional clearance studies performed in adolescent boys with native kidneys or functioning renal transplants. The larger value for the constant k (0.7) and the age correction for GFR reflect the greater rate of urinary creatine excretion (and thus muscle mass) per unit of body mass in adolescent boys.
我们重新研究了212名女孩和356名男孩中肌酐清除率（Ccr）与身体形态之间的关系，其中包括181名年龄在13至21岁之间的男孩和69名女孩。使用公式Ccr = k×L/Pcr（计算肾小球滤过率（GFR）时k = 0.55）会导致青少年男孩的GFR被显著低估，但该公式适用于女孩。对于51名青少年男孩，公式Ccr = 0.7×L/Pcr能准确估算GFR。对133名年龄在3至21岁之间的男孩进行回归分析表明，常数k随年龄逐渐呈线性增加（r = 0.35，P < 0.01）。通过线性双变量方程Ccr = 1.5×（年龄）+ 0.5×（L/Pcr）（年龄以年为单位）可以更好地估算任何年龄男孩的GFR（r = 0.82，P < 0.001）。在对具有正常肾脏或功能性肾移植的青少年男孩进行的另外91项清除率研究中，该方程的结果略优于0.7×L/Pcr。常数k的较大值（0.7）以及对GFR的年龄校正反映了青少年男孩每单位体重中尿肌酐排泄率（进而肌肉量）更高。
