Osther P J
Odense Universitet, Klinisk Institut.
Ugeskr Laeger. 1993 Nov 22;155(47):3835-9.
Citrate is an important naturally occurring inhibitor of calcium stone formation in urine. Urinary citrate excretion was examined in 43 consecutive patients with recurrent idiopathic calcium nephrolithiasis and in 50 normal controls by a specific enzymatic technique. Hypocitraturia (< 1.6 mmol/24h) was found in 14 (33%) stone formers compared to 6 (12%) normal controls (p = 0.03). Citrate excretion expressed as citrate-creatinine ratio in 24 hour urine samples was significantly lower in the stone formers than in the healthy controls (p = 0.03), and significantly lower in healthy men, compared to healthy females (p = 0.006). There was a great variability in urinary citrate levels in both groups, and a considerable overlap in the urinary citrate excretion between normal subjects and stone formers. Factors other than urinary citrate excretion must therefore be of importance in the pathophysiology of calcium stone formation. Citrate-calcium ratio in urine proved to be a reliable index in discriminating stone formers from healthy subjects.
枸橼酸盐是尿液中一种重要的天然钙结石形成抑制剂。采用特定的酶技术，对43例复发性特发性钙肾结石患者及50名正常对照者的尿枸橼酸盐排泄情况进行了检测。14例（33%）结石形成者出现低枸橼酸盐尿症（<1.6 mmol/24小时），而正常对照者中有6例（12%）出现低枸橼酸盐尿症（p = 0.03）。结石形成者24小时尿样中以枸橼酸盐 - 肌酐比值表示的枸橼酸盐排泄量显著低于健康对照者（p = 0.03），且与健康女性相比，健康男性的该比值显著更低（p = 0.006）。两组的尿枸橼酸盐水平均存在很大差异，正常受试者与结石形成者之间的尿枸橼酸盐排泄量也有相当程度的重叠。因此，除尿枸橼酸盐排泄外的其他因素在钙结石形成的病理生理学中必定也很重要。尿中枸橼酸盐 - 钙比值被证明是区分结石形成者与健康受试者的可靠指标。
