Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China,
Urol Int. 2022;106(3):227-234. doi: 10.1159/000513321. Epub 2021 Mar 19.
The purpose of this study in a small group of non-stone-forming Chinese persons was to measure the levels of supersaturation with calcium oxalate and calcium phosphate and pH with the aim of confirming if any of the different short-term urine samples were better for risk evaluation than a 24-h sample. Nine normal men and 1 woman collected urine during 4 periods of the day. Period 1 between 08 and 12 h, Period 2 between 12 and 18 h, Period 3 between 18 and 22 h, and Period 4 between 22 and 08 h. Each sample was analysed for calcium, oxalate, citrate, magnesium and phosphate, and estimates of supersaturation with calcium oxalate (CaOx) and calcium phosphate (CaP) were expressed in terms of AP(CaOx) and AP(CaP) index. An estimate of the solute load of CaOx was also calculated. Urine composition for 24-h urine (Period 24) was obtained mathematically from the analysed variables. Urine composition corresponding to 14-h urine portions 22-12 h (Period 14N) and 08-22 h (Period 14 D) were calculated. The lowest pH levels were recorded in Period 1 urine. The highest level of AP(CaOx) index was recorded during Period 1, and the product AP(CaOx) index × 107 × hydrogen ion concentration was significantly higher in Period 1 urine than in 24-h urine (p = 0.02). Also, the product SL(CaOx) × 107 × hydrogen ion concentration was significantly higher in Period 1 urine (p = 0.02). Low AP (CaP) index levels were recorded in Period 4, but also in all periods following dietary loads of calcium and phosphate. With the important reservation that the analytical results were obtained from non-stone-forming persons, the conclusion is that analysis of urine samples collected between 08 and 12 h might be an alternative to 24-h urine. The risk evaluation might advantageously be expressed either in terms of the product AP(CaOx) index × 107 × hydrogen ion concentration or the product SL(CaOx) × 107 × hydrogen ion concentration.
本研究旨在测量草酸钙和磷酸钙的过饱和度以及 pH 值，以确认短期尿液样本中是否有任何样本比 24 小时尿液样本更适合风险评估。9 名正常男性和 1 名女性在一天中的 4 个时间段收集尿液。第 1 时间段为 08 点至 12 点，第 2 时间段为 12 点至 18 点，第 3 时间段为 18 点至 22 点，第 4 时间段为 22 点至 08 点。每个样本均分析了钙、草酸、柠檬酸、镁和磷酸盐，并以 AP（草酸钙）和 AP（磷酸钙）指数的形式表示草酸钙（CaOx）和磷酸钙（CaP）的过饱和度。还计算了草酸钙溶质负荷的估计值。24 小时尿液（第 24 时间段）的尿液成分通过分析变量数学获得。计算了 22-12 小时（第 14N 时间段）和 08-22 小时（第 14D 时间段）的 14 小时尿液部分的尿液成分。第 1 时间段的尿液 pH 值最低。AP（草酸钙）指数最高记录在第 1 时间段，第 1 时间段的 AP（草酸钙）指数×107×氢离子浓度乘积显著高于 24 小时尿液（p=0.02）。此外，SL（草酸钙）×107×氢离子浓度乘积在第 1 时间段的尿液中显著更高（p=0.02）。第 4 时间段记录到低 AP（磷酸钙）指数，但在摄入钙和磷酸盐负荷后的所有时间段也记录到低 AP（磷酸钙）指数。有一个重要的保留意见，即分析结果是从非结石形成者获得的，结论是，在 08 点至 12 点之间收集的尿液样本的分析可能是 24 小时尿液的替代方法。风险评估可以有利地表示为 AP（草酸钙）指数×107×氢离子浓度乘积或 SL（草酸钙）×107×氢离子浓度乘积。
