Criterion values for urine-specific gravity and urine color representing adequate water intake in healthy adults

• Published in: European journal of clinical nutrition Vol. 71; no. 4; pp. 561 - 563
• Main Authors: Perrier, E T, Bottin, J H, Vecchio, M, Lemetais, G
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.04.2017; Nature Publishing Group
• Subjects: 631/443/272; 692/53; Adult; Body water; Clinical Nutrition; Color - standards; Drinking; Drinking (Physiology); Drinking water; Epidemiology; Female; Health behavior; Health risks; Healthy Volunteers; Humans; Hydration; Internal Medicine; Male; Measurement; Medicine; Medicine & Public Health; Metabolic Diseases; Methods; Organism Hydration Status - physiology; Physiological research; Public Health; Reference Values; ROC Curve; Sensitivity and Specificity; Short Communication; Specific Gravity; Urinalysis; Urinalysis - statistics & numerical data; Urine; Urine - chemistry; Young Adult
• ISSN: 0954-3007; 1476-5640
• DOI: 10.1038/ejcn.2016.269

Growing evidence suggests a distinction between water intake necessary for maintaining a euhydrated state, and water intake considered to be adequate from a perspective of long-term health. Previously, we have proposed that maintaining a 24-h urine osmolality ( U Osm ) of ⩽500 mOsm/kg is a desirable target for urine concentration to ensure sufficient urinary output to reduce renal health risk and circulating vasopressin. In clinical practice and field monitoring, the measurement of U Osm is not practical. In this analysis, we calculate criterion values for urine-specific gravity ( U SG ) and urine color ( U Col ), two measures which have broad applicability in clinical and field settings. A receiver operating characteristic curve analysis performed on 817 urine samples demonstrates that a U SG ⩾1.013 detects U Osm >500 mOsm/kg with very high accuracy (AUC 0.984), whereas a subject-assessed U Col ⩾4 offers high sensitivity and moderate specificity (AUC 0.831) for detecting U Osm >500 m Osm/kg.