Impact of Potassium Citrate vs Citric Acid on Urinary Stone Risk in Calcium Phosphate Stone Formers
Impact of Potassium Citrate vs Citric Acid on Urinary Stone Risk in Calcium Phosphate Stone Formers
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DOI：
10.1016/j.juro.2018.07.039
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发表时间：
2018-12-01
影响因子：
6.6
通讯作者：
Maalouf, Naim M.
中科院分区：
文献类型：
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作者：
Doizi, Steeve;Poindexter, John R.;Maalouf, Naim M.
目的：据我们所知，没有药物被证明是有效的预防复发性磷酸钙尿路结石。柠檬酸钾可能通过促进尿中柠檬酸盐的排泄和降低尿钙来预防磷酸钙结石，但它会提高尿pH值，从而增加磷酸钙饱和度，并可能抵消有益的效果。柠檬酸可以潜在地提高尿液的柠檬酸盐，但不是pH值，因此，可能是一种有用的对抗磷酸钙结石的对策。我们评估了这两种药物是否能显著改变尿液成分和降低磷酸钙饱和度。材料和方法：在一项交叉代谢研究中，13例复发性磷酸钙结石患者无高钙尿症，在为期31周的研究阶段结束时进行评估，在此期间，他们摄入固定的代谢饮食，并接受指定的研究药物，包括柠檬酸30 mEq，每天两次，柠檬酸钾20 mEq，每天两次或匹配的安慰剂。我们收集24小时尿液标本进行尿液化学研究并计算磷酸钙饱和度指数。结果：柠檬酸期和安慰剂期的尿液参数无显著差异。与柠檬酸和安慰剂相比，柠檬酸钾显著提高了尿pH值、钾和柠檬酸（p < 0.01），并有降低尿钙的趋势（p = 0.062）。用相对过饱和比计算，柠檬酸钾增加了刷子石的饱和度，但不增加饱和指数。结论：每天60meq剂量的柠檬酸没有显著改变磷酸钙结石患者的尿液组成。柠檬酸钾对磷酸钙结石复发的远期影响有待进一步研究。
Purpose: To our knowledge no medication has been shown to be effective for preventing recurrent calcium phosphate urinary stones. Potassium citrate may protect against calcium phosphate stones by enhancing urine citrate excretion and lowering urine calcium but it raises urine pH, which increases calcium phosphate saturation and may negate the beneficial effects. Citric acid can potentially raise urine citrate but not pH and, thus, it may be a useful countermeasure against calcium phosphate stones. We assessed whether these 2 agents could significantly alter urine composition and reduce calcium phosphate saturation.Materials and Methods: In a crossover metabolic study 13 recurrent calcium phosphate stone formers without hypercalciuria were evaluated at the end of 3, 1-week study phases during which they consumed a fixed metabolic diet and received assigned study medications, including citric acid 30 mEq twice daily, potassium citrate 20 m Eq twice daily or matching placebo. We collected 24-hour urine specimens to perform urine chemistry studies and calculate calcium phosphate saturation indexes.Results: Urine parameters did not significantly differ between the citric acid and placebo phases. Potassium citrate significantly increased urine pH, potassium and citrate compared to citric acid and placebo (p < 0.01) with a trend toward lower urine calcium (p = 0.062). Brushite saturation was increased by potassium citrate when calculated by the relative supersaturation ratio but not by the saturation index.Conclusions: Citric acid at a dose of 60 mEq per day did not significantly alter urine composition in calcium phosphate stone formers. The long-term impact of potassium citrate on calcium phosphate stone recurrence needs to be studied further.