常吃的无咖啡因苏打水中的柠檬酸盐、苹果酸盐和碱含量：对肾结石治疗的影响。

Citrate, malate and alkali content in commonly consumed diet sodas: implications for nephrolithiasis treatment.

机构信息

Department of Urology, University of California-San Francisco, San Francisco, California, USA.

出版信息

J Urol. 2010 Jun;183(6):2419-23. doi: 10.1016/j.juro.2010.02.2388. Epub 2010 Apr 18.

DOI:10.1016/j.juro.2010.02.2388

PMID:20403610

Abstract

PURPOSE

Citrate is a known inhibitor of calcium stone formation. Dietary citrate and alkali intake may have an effect on citraturia. Increasing alkali intake also increases urine pH, which can help prevent uric acid stones. We determined citrate, malate and total alkali concentrations in commonly consumed diet sodas to help direct dietary recommendations in patients with hypocitraturic calcium or uric acid nephrolithiasis.

MATERIALS AND METHODS

Citrate and malate were measured in a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis and in 15 diet sodas. Anions were measured by ion chromatography. The pH of each beverage was measured to allow calculation of the unprotonated anion concentration using the known pK of citric and malic acid. Total alkali equivalents were calculated for each beverage. Statistical analysis was done using Pearson's correlation coefficient.

RESULTS

Several sodas contained an amount of citrate equal to or greater than that of alkali and total alkali as a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis (6.30 mEq/l citrate as alkali and 6.30 as total alkali). These sodas were Diet Sunkist Orange, Diet 7Up, Sprite Zero, Diet Canada Dry Ginger Ale, Sierra Mist Free, Diet Orange Crush, Fresca and Diet Mountain Dew. Colas, including Caffeine Free Diet Coke, Coke Zero, Caffeine Free Diet Pepsi and Diet Coke with Lime, had the lowest total alkali (less than 1.0 mEq/l). There was no significant correlation between beverage pH and total alkali content.

CONCLUSIONS

Several commonly consumed diet sodas contain moderate amounts of citrate as alkali and total alkali. This information is helpful for dietary recommendations in patients with calcium nephrolithiasis, specifically those with hypocitraturia. It may also be useful in patients with low urine pH and uric acid stones. Beverage malate content is also important since malate ingestion increases the total alkali delivered, which in turn augments citraturia and increases urine pH.

摘要

目的

柠檬酸盐是已知的钙结石形成抑制剂。饮食中的柠檬酸盐和碱的摄入可能会影响柠檬酸排泄。增加碱的摄入也会增加尿 pH 值，这有助于预防尿酸结石。我们测定了常见饮用苏打水中的柠檬酸盐、苹果酸盐和总碱浓度，以帮助指导低柠檬酸钙或尿酸肾结石患者的饮食建议。

材料和方法

测定了一种常用于治疗低柠檬酸钙肾结石的柠檬水和 15 种苏打水中的柠檬酸盐和苹果酸盐。采用离子色谱法测定阴离子。测量每种饮料的 pH 值，以便根据柠檬酸和苹果酸的已知 pK 值计算未质子化的阴离子浓度。计算了每种饮料的总碱当量。采用 Pearson 相关系数进行统计学分析。

结果

几种苏打水中的柠檬酸含量与治疗低柠檬酸钙肾结石常用的柠檬水（6.30mEq/L 柠檬酸作为碱和 6.30 作为总碱）相等或更高。这些苏打水包括 Diet Sunkist Orange、Diet 7Up、Sprite Zero、Diet Canada Dry Ginger Ale、Sierra Mist Free、Diet Orange Crush、Fresca 和 Diet Mountain Dew。可乐类饮料，包括无咖啡因 Diet Coke、Coke Zero、无咖啡因 Diet Pepsi 和 Diet Coke with Lime，总碱含量最低（小于 1.0mEq/L）。饮料 pH 值与总碱含量之间无显著相关性。