Rudman D, Kutner M H, Redd S C, Waters W C, Gerron G G, Bleier J
J Clin Endocrinol Metab. 1982 Dec;55(6):1052-7. doi: 10.1210/jcem-55-6-1052.
Several investigators have reported that hypocitraturia is frequent in patients with idiopathic kidney stones. In these studies, however, glomerular filtration rate, urinary tract infection, sex, diet, time of day, and medications, all potentially influential variables, were uncontrolled. Fifteen men, aged 30-52 yr, with recurrent idiopathic calcium oxalate stones and 15 normal age-matched men were studied. Patients with hyperparathyroidism, renal tubular acidosis, reduced creatinine clearance (less than 80 ml . min/1.73 M2), or urinary infection were excluded. Medications were stopped 2 weeks before the study began. A standard constant diet, furnishing 800 mg calcium and free of citrate, was fed for 20 days. During the last 10 days, 4.5 g sodium citrate were given orally. Eight-hour collections of urine were analyzed for calcium and citrate. Filtered load and net tubular reabsorption of citrate were also calculated. The 24-h urinary excretion of calcium was elevated in eight stone formers, and citrate excretion was depressed in seven. Five patients were both hypercalciuric anc hypocitraturic. The hypocitraturia resulted from excessive net tubular reabsorption of a normal filtered load of citrate. Urinary citrate was highest between 0800-1600 h, whereas calcium was highest between 1600-2400 h; both components were lowest between 2400-0800 h. The diurnal profiles of urinary calcium and citrate were similar in the stone formers and in the normal men. Oral sodium citrate did not influence urinary citrate in either group. These data suggest that in adult men, hypocitraturia may be a common predisposing factor for calcific nephrolithiasis.
几位研究者报告称，特发性肾结石患者中低枸橼酸尿症很常见。然而，在这些研究中，肾小球滤过率、尿路感染、性别、饮食、一天中的时间以及药物等所有可能有影响的变量均未得到控制。对15名年龄在30 - 52岁之间、患有复发性特发性草酸钙结石的男性以及15名年龄匹配的正常男性进行了研究。排除了患有甲状旁腺功能亢进、肾小管酸中毒、肌酐清除率降低（低于80 ml·min/1.73 M2）或尿路感染的患者。在研究开始前2周停用药物。给予标准的恒定饮食，提供800 mg钙且不含枸橼酸盐，持续20天。在最后10天，口服4.5 g柠檬酸钠。对8小时尿液收集样本进行钙和枸橼酸盐分析。还计算了枸橼酸盐的滤过负荷和肾小管净重吸收量。8名结石形成者的24小时尿钙排泄量升高,7名的枸橼酸盐排泄量降低。5名患者同时存在高钙尿症和低枸橼酸尿症。低枸橼酸尿症是由于肾小管对正常滤过负荷的枸橼酸盐过度净重吸收所致。尿枸橼酸盐在08:00 - 16:00时最高，而钙在16:00 - 24:00时最高；两者在24:00 - 08:00时均最低。结石形成者和正常男性的尿钙和枸橼酸盐的日变化曲线相似。口服柠檬酸钠对两组的尿枸橼酸盐均无影响。这些数据表明，在成年男性中，低枸橼酸尿症可能是钙化性肾结石的常见易感因素。
