Luft F C, Aronoff G R, Sloan R S, Fineberg N S
Am J Kidney Dis. 1986 May;7(5):375-80. doi: 10.1016/s0272-6386(86)80085-3.
To elucidate patterns of dietary sodium ingestion in free-living subjects, we collected 26 consecutive 24-hour urine specimens in 18 subjects who had not received instructions to limit the sodium content of their diets, and who were not aware that sodium intake would be estimated from the collections. Nine subjects with plasma creatinine values less than 2 mg/dL had a mean 24-hour UNaV of 156 mEq/d, with an interindividual variability of SD +/- 38 mEq. Their intraindividual variability was 61 mEq. Nine subjects with creatinine values greater than 2 mg/dL had a mean 24-hour UNaV of 108 mEq/d (P less than 0.05). The intraindividual variability of these subjects was 39 mEq/d. Subjects with normal renal function ingested more sodium than subjects with renal insufficiency, although the variability in both groups was extensive. These data confirm and extend earlier observations and illustrate the difficulty in identifying biologic correlations in the presence of considerable intraindividual variability. They underscore the futility of estimating mean dietary sodium intake with a single or occasional 24-hour urine collection in both normal subjects and patients with renal insufficiency.
为了阐明自由生活人群的膳食钠摄入模式，我们收集了18名未接受限制饮食钠含量指导且未意识到将通过尿液收集来估算钠摄入量的受试者连续26份24小时尿液样本。9名血浆肌酐值低于2mg/dL的受试者24小时尿钠排泄量均值为156mEq/d，个体间标准差为±38mEq，个体内变异为61mEq。9名肌酐值高于2mg/dL的受试者24小时尿钠排泄量均值为108mEq/d（P<0.05），这些受试者的个体内变异为39mEq/d。肾功能正常的受试者比肾功能不全的受试者摄入更多的钠，尽管两组的变异都很大。这些数据证实并扩展了早期的观察结果，说明了在存在显著个体内变异的情况下识别生物学相关性的困难。它们强调了在正常受试者和肾功能不全患者中通过单次或偶尔一次24小时尿液收集来估算平均膳食钠摄入量是徒劳的。
