目的：最近的研究表明，最佳饮水量的24小时尿渗透压（UOsm）应保持<500mmol·kg-1。这项研究的目的是确定健康成年人的总饮水量（TWI）要求，以保持24小时尿液渗透压<500mmol·kg-1所表明的最佳水合作用。
方法：对居住在美国的49名男性和50名女性（年龄：41±14岁，体重指数：26.3±5.2kg·m-2）。TWI是根据7天的水量来评估的，使用氧化氘的稀释液，校正了代谢性水的产生。使用受试者工作特征（ROC）分析分别在男性和女性中评估TWI识别UOsm<500mmol·kg-1的诊断准确性。
结果：24小时UOsm分别为482±229和346±182mmol·kg-1，TWI分别为3.57±1.10L·d-1和3.20±1.27L·d-1在男性和女性中，分别。ROC分析检测男性24小时UOsm<500mmol·kg-1的曲线下面积（AUC）为77.4％，灵敏度高，特异性，阈值为83.3%，64.5%,和3.39L·d-1。有敏感性的女性的AUC为82.4%,特异性，阈值为85.7%，72.1%,和2.61L·d-1。
结论：考虑男性和女性的阈值分别为3.4L·d-1和2.6L·d-1，保持TWI符合美国国家医学院的指南，男性为3.7L·d-1，女性为2.7L·d-1，对于美国大多数人来说，应足以维持24小时UOsm<500mmol·kg-1。
OBJECTIVE: Recent studies suggest that 24-h urine osmolality (UOsm) for optimal water intake should be maintained < 500 mmol·kg-1. The purpose of this study was to determine the total water intake (TWI) requirement for healthy adults to maintain optimal hydration as indicated by 24-h urine osmolality < 500 mmol·kg-1.
METHODS: Twenty-four-hour UOsm was assessed in 49 men and 50 women residing in the United States (age: 41 ± 14 y, body mass index: 26.3 ± 5.2 kg·m-2). TWI was assessed from 7-day water turnover, using a dilution of deuterium oxide, corrected for metabolic water production. The diagnostic accuracy of TWI to identify UOsm < 500 mmol·kg-1 was evaluated using receiver operating characteristic (ROC) analysis in men and women separately.
RESULTS: Twenty-four-hour UOsm was 482 ± 229 and 346 ± 182 mmol·kg-1 and TWI was 3.57 ± 1.10 L·d-1 and 3.20 ± 1.27 L·d-1 in men and women, respectively. ROC analysis for TWI detecting 24-h UOsm < 500 mmol·kg-1 in men yielded an area under the curve (AUC) of 77.4% with sensitivity, specificity, and threshold values of 83.3%, 64.5%, and 3.39 L·d-1, respectively. The AUC was 82.4% in women with sensitivity, specificity, and threshold values of 85.7%, 72.1%, and 2.61 L·d-1.
CONCLUSIONS: Considering threshold values in men and women of 3.4 L·d-1 and 2.6 L·d-1, respectively, maintaining TWI in line with National Academy of Medicine
guidelines of 3.7 L·d-1 in men and 2.7 L·d-1 in women should be sufficient for most individuals in the United States to maintain 24-h UOsm < 500 mmol·kg-1.
