Department of Urology, Chungbuk National University, Cheongju, South Korea.
J Urol. 2010 Oct;184(4):1372-6. doi: 10.1016/j.juro.2010.06.019. Epub 2010 Aug 17.
Sodium restriction is widely recommended to prevent urinary stone recurrence. However, the effect of urinary sodium excretion has not been fully evaluated. We investigated the relationship between urinary sodium, urinary metabolite excretion and the risk of recurrence in urinary stone formers.
Selected for study were 798 stone formers with no evidence of metabolic disorders as the cause of abnormal urinary solutes. We analyzed the relationship between urinary sodium and other metabolic parameters by gender. Values were adjusted by covariates according to correlation status. Patients were divided into stone formers with hypernatriuresis or normal natriuresis (less than 220 mEq daily) and urinary parameters were compared. Kaplan-Meier analysis was done to determine the cumulative incidence of recurrent stones by urinary sodium. Patients were considered recurrence-free at a minimum followup of 3 years without incidence.
In the 492 men and 306 women mean ± SD age was 40.0 ± 11.4 and 45.4 ± 12.7 years, and mean body mass index was 23.9 ± 3.1 and 23.0 ± 3.0 kg/m(2), respectively. Using covariate adjusted partial correlation coefficients urinary sodium was noted to influence volume, pH, calcium, uric acid, oxalate and citrate in men, and volume, pH, calcium, uric acid and citrate in women (each p <0.05). At a median followup of 56.1 months 46 of 98 stone formers (46.9%) with normal natriuresis experienced stone recurrence vs 60 of 93 (64.5%) with hypernatriuresis. Patients with hypernatriuresis also had significantly decreased time to recurrence than those with normal natriuresis (log rank test p = 0.043).
Results show that urinary sodium is an important determinant of other stone forming parameters and of the risk of recurrent stones. These findings suggest that a sodium restricted diet should be the initial step when treating stone formers.
限制钠的摄入被广泛推荐用于预防尿路结石复发。然而，尿钠排泄的效果尚未得到充分评估。我们研究了尿钠与尿代谢产物排泄和结石形成者复发风险之间的关系。
选择 798 名无代谢紊乱证据的结石形成者作为研究对象，这些异常尿液溶质是由其他原因引起的。我们按性别分析了尿钠与其他代谢参数之间的关系。根据相关状态调整了协变量值。将患者分为高尿钠或正常尿钠（每日少于 220mEq）结石形成者，并比较尿参数。通过 Kaplan-Meier 分析确定尿钠对复发性结石累积发生率的影响。至少随访 3 年无复发者被认为无复发。
在 492 名男性和 306 名女性中，平均年龄±SD 分别为 40.0±11.4 和 45.4±12.7 岁，平均体重指数分别为 23.9±3.1 和 23.0±3.0kg/m²。使用协变量调整的偏相关系数，尿钠影响男性的体积、pH 值、钙、尿酸、草酸盐和柠檬酸，以及女性的体积、pH 值、钙、尿酸和柠檬酸（p<0.05）。在中位随访 56.1 个月时，98 名正常尿钠结石形成者中有 46 名（46.9%）发生结石复发，93 名高尿钠结石形成者中有 60 名（64.5%）发生结石复发。高尿钠组患者的复发时间明显短于正常尿钠组（对数秩检验 p=0.043）。
结果表明，尿钠是其他结石形成参数和结石复发风险的重要决定因素。这些发现表明，在治疗结石形成者时，应首先限制钠的摄入。
