Holmes R P, Goodman H O, Hart L J, Assimos D G
Department of Urology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina.
Kidney Int. 1993 Aug;44(2):366-72. doi: 10.1038/ki.1993.253.
The relationship of protein intake to urinary oxalate and glycolate excretion was examined in a large cohort (N = 101) of normal individuals on self-selected diets and in 11 individuals on controlled protein diets. On self-selected diets no correlation was detected between protein intake and urinary oxalate or glycolate excretion. A moderate but significant correlation (r = 0.45; P < 0.001) of oxalate with urea excretion was observed in males but not females, suggesting that there may be a link between urea and oxalate synthesis in males. On controlled protein diets mean oxalate excretion in females on days 7 to 10 of a high protein diet (1.8 g/kg body wt) was 20% higher than on a low protein diet (0.6 g/kg body wt; P = 0.02), but there was no difference in males. Glycolate excretion was significantly higher (P < 0.001) on the high protein diet than on the low protein diet in both sexes. Only a weak precursor-product relationship was observed between glycolate and oxalate. A gender effect was apparent on both self-selected and control diets with females excreting more oxalate and glycolate relative to creatinine than males. A pronounced inter- and intra-individual variability in the excretion of oxalate was observed, even on controlled diets. This suggests that genetic factors and physiological changes such as hormonal fluctuations may contribute more to the variability in oxalate excretion than the dietary intake of protein.
在一个由101名正常个体组成的大样本队列中，这些个体采用自选饮食，同时选取了11名采用控制蛋白质饮食的个体，研究了蛋白质摄入量与尿草酸和乙醇酸排泄之间的关系。在自选饮食中，未检测到蛋白质摄入量与尿草酸或乙醇酸排泄之间存在相关性。在男性中观察到草酸与尿素排泄之间存在中度但显著的相关性（r = 0.45；P < 0.001），而女性中未观察到，这表明男性中尿素和草酸合成之间可能存在联系。在控制蛋白质饮食中，女性在高蛋白饮食（1.8 g/kg体重）的第7至10天的平均草酸排泄量比低蛋白饮食（0.6 g/kg体重；P = 0.02）时高20%，但男性中无差异。两性中，高蛋白饮食时的乙醇酸排泄量均显著高于低蛋白饮食（P < 0.001）。仅观察到乙醇酸和草酸之间存在较弱的前体-产物关系。在自选饮食和对照饮食中均明显存在性别效应，相对于肌酐，女性排泄的草酸和乙醇酸比男性更多。即使在控制饮食时，草酸排泄也存在明显的个体间和个体内变异性。这表明遗传因素和诸如激素波动等生理变化可能比蛋白质的饮食摄入量对草酸排泄的变异性贡献更大。
