Siener Roswitha, Ebert Dagmar, Nicolay Claudia, Hesse Albrecht
Department of Urology, and Institute of Medical Biometry, Informatics and Epidemiology, University of Bonn, Bonn, Germany.
Kidney Int. 2003 Mar;63(3):1037-43. doi: 10.1046/j.1523-1755.2003.00807.x.
Hyperoxaluria is a major predisposing factor in calcium oxalate urolithiasis. The aim of the present study was to clarify the role of dietary oxalate in urinary oxalate excretion and to assess dietary risk factors for hyperoxaluria in calcium oxalate stone patients.
Dietary intakes of 186 calcium oxalate stone formers, 93 with hyperoxaluria (>or=0.5 mmol/day) and 93 with normal oxalate excretion (<0.4 mmol/day), were assessed by a 24-hour weighed dietary record. Each subject collected 24-hour urine during the completion of the food record. Oxalate content of foods was measured by a recently developed analytical method.
The mean daily intakes of energy, total protein, fat and carbohydrates were similar in both groups. The diets of the patients with hyperoxaluria were estimated to contain 130 mg/day oxalate and 812 mg/day calcium as compared to 101 mg/day oxalate and 845 mg/day calcium among patients without hyperoxaluria. These differences were not significant. The mean daily intakes of water (in food and beverages), magnesium, potassium, dietary fiber and ascorbic acid were greater in patients with hyperoxaluria than in stone formers with normal oxalate excretion. Multiple logistic regression analysis revealed that urinary oxalate excretion was significantly associated with dietary ascorbate and fluid intake, and inversely related to calcium intake. Differences of estimated diet composition of both groups corresponded to differences in urinary parameters.
These findings suggest that hyperoxaluria predominantly results from increased endogenous production and from intestinal hyperabsorption of oxalate, partly caused by an insufficient supply or low availability of calcium for complexation with oxalate in the intestinal lumen.
高草酸尿症是草酸钙尿路结石的主要诱发因素。本研究的目的是阐明膳食草酸盐在尿草酸排泄中的作用，并评估草酸钙结石患者高草酸尿症的膳食风险因素。
通过24小时称重膳食记录评估186例草酸钙结石形成者的膳食摄入量，其中93例患有高草酸尿症（≥0.5 mmol/天），93例草酸排泄正常（<0.4 mmol/天）。每位受试者在完成食物记录期间收集24小时尿液。食物中的草酸盐含量通过最近开发的分析方法进行测量。
两组的每日能量、总蛋白、脂肪和碳水化合物的平均摄入量相似。高草酸尿症患者的饮食估计每天含有130毫克草酸盐和812毫克钙，而无高草酸尿症患者的饮食中草酸盐含量为每天101毫克，钙含量为845毫克。这些差异不显著。高草酸尿症患者的水（食物和饮料中）、镁、钾、膳食纤维和抗坏血酸的平均每日摄入量高于草酸排泄正常的结石形成者。多因素logistic回归分析显示，尿草酸排泄与膳食抗坏血酸和液体摄入量显著相关，与钙摄入量呈负相关。两组估计饮食组成的差异与尿液参数的差异相对应。
这些发现表明，高草酸尿症主要源于内源性草酸生成增加和肠道对草酸盐的过度吸收，部分原因是肠道腔内用于与草酸盐络合的钙供应不足或利用率低。
