Kirkland J L, Lye M, Levy D W, Banerjee A K
Br Med J (Clin Res Ed). 1983 Dec 3;287(6406):1665-7. doi: 10.1136/bmj.287.6406.1665.
Twenty four young (mean age 29.2 years, range 25-35) and 21 elderly (mean age 66.5, range 60-80) healthy subjects collected their urine in timed aliquots over 24 hours. The elderly subjects had been selected for their fitness by clinical and laboratory examinations and all lived independently at home. Sodium and potassium excretions were reduced in the elderly subjects compared with the young subjects, potassium excretion considerably so. This was despite similar 24 hour urine volumes and total solute excretion by both groups. The ratios of rates of excretion of water, electrolytes, and solutes during the night to the rates of excretion during the day were found to be higher in the elderly than the young subjects. Reduced day to night ratios of urinary excretion may be partly responsible for complaints of nocturia and sleep disturbance in elderly people.
24名年轻（平均年龄29.2岁，范围25 - 35岁）和21名老年（平均年龄66.5岁，范围60 - 80岁）健康受试者在24小时内定时收集尿液样本。老年受试者通过临床和实验室检查筛选出身体状况良好，且均独立居家生活。与年轻受试者相比，老年受试者的钠和钾排泄量减少，钾排泄量减少尤为明显。尽管两组的24小时尿量和总溶质排泄量相似。结果发现，老年人夜间水、电解质和溶质排泄率与白天排泄率的比值高于年轻人。老年人夜间尿量排泄率与白天比值降低可能是导致夜尿症和睡眠障碍的部分原因。
