Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.
Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.
Auton Neurosci. 2021 Jul;233:102797. doi: 10.1016/j.autneu.2021.102797. Epub 2021 Mar 19.
Sodium intake and compliance with dietary sodium modification are typically assessed using a 24-h urine collection analyzed using flame photometry, but this is inconvenient. Spot urine samples have been investigated as alternatives to 24-h collections, but their accuracy is poor. Since sodium and chloride are present in equal concentrations in dietary salt, chloride test strips may provide a suitable proxy for at-home measurement of urine sodium concentrations. We aimed to determine whether (i) chloride test strips provide a reliable measure of urinary sodium compared to the gold standard flame photometry and (ii) multiple spot samples accurately reflect 24-h urine sodium. We recruited 43 participants (19 males) aged 23.6 ± 0.6 years to complete multiple consecutive spot samples (morning and evening) along with a 24-h urine sodium collection. Urine 24-h sodium estimates using chloride test strips (114.6 ± 7.5 mmol/day) were highly correlated (r = 0.900, p < 0.0001) with flame photometry (121.1 ± 7.7 mmol/day) with a bias of -6.53 ± 22.2 mmol/day. Use of a three-spot sample average (both morning and evening spot samples) with a correction factor applied (122.9 ± 4.1 mmol/day) provided a good approximation of 24-h sodium measured by flame photometry (125.6 ± 9.0 mmol/day), with a bias of -2.55 ± 43.9 mmol/day. Chloride test strips applied to a 24-h urine collection provide a highly accurate measure of urinary sodium excretion, permitting convenient at-home sample collection and analysis. Their application to multiple spot samples provides a reasonable approximation of sodium excretion that can be used to conveniently monitor attempts at dietary sodium manipulation, without the inconvenience of completing a 24-h urine sample.
钠摄入量和对饮食中钠的修改的遵守情况通常使用 24 小时尿液收集来评估，并用火焰光度法进行分析，但这很不方便。点尿样已被研究作为 24 小时收集的替代品，但它们的准确性较差。由于钠和氯在膳食盐中的浓度相等，氯测试条可能提供用于在家测量尿钠浓度的合适替代方法。我们旨在确定（i）氯测试条与金标准火焰光度法相比是否能可靠地衡量尿中的钠含量，以及（ii）多个点样本是否准确反映 24 小时尿钠含量。我们招募了 43 名年龄为 23.6 ± 0.6 岁的参与者，让他们连续完成多次点样（早晨和晚上）和 24 小时尿钠收集。氯测试条法估计的 24 小时尿钠值（114.6 ± 7.5 mmol/天）与火焰光度法高度相关（r = 0.900，p < 0.0001），偏差为-6.53 ± 22.2 mmol/天。使用三个点样平均值（早晨和晚上的点样）并应用校正因子（122.9 ± 4.1 mmol/天）可以很好地近似用火焰光度法测量的 24 小时钠值（125.6 ± 9.0 mmol/天），偏差为-2.55 ± 43.9 mmol/天。应用于 24 小时尿液收集的氯测试条可高度准确地衡量尿钠排泄量，可方便地进行家庭样本采集和分析。将其应用于多个点样可以提供钠排泄量的合理近似值，可方便地监测饮食钠干预的尝试，而无需完成 24 小时尿液样本的不便。
