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Evaluation of Uosm:Posm ratio and Posm as Hydration Biomarkers in Healthy Young Women During Daily Activities
Author(s) -
Armstrong Lawrence E,
Johnson Evan C,
Munoz Colleen X,
LeBellego Laurent,
Klein Alexis,
Casa Douglas J,
Maresh Carl M.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1084.14
Subject(s) - chemistry , morning , zoology , fluid intake , plasma osmolality , medicine , endocrinology , biology , vasopressin
The urine‐to‐plasma osmolality ratio (U osm :P osm ) is used clinically to diagnose renal and metabolic disorders. U osm :P osm <1 also represents a state of relative water excess. Diet records of 120 college women were analyzed [beverage water + food water = total fluid intake (TFI)] for 5d to identify 14 high volume (HIGH) and 14 low volume (LOW) drinkers (age, 20.3±1.7 y). Experimental protocol: 2 baseline days verified ad libitum TFI status of HIGH (3.21 L/d) and LOW (1.64 L/d). During a controlled intervention (days 3–6) with mineral water (Volvic™), HIGH consumed less than baseline (TFI, 2.00 L/d; H↔L) and LOW consumed more than baseline (TFI, 3.50 L/d; L↔H). On ad libitum recovery day 7, TFI were: HIGH, 3.17, LOW, 1.71 L/d. Duplicate U osm (24h collection) and P osm (morning) samples were analyzed via freezing point depression osmometry. Mean (± SD) U osm :P osm were H↔L: d1, 1.3±0.4; d2, 1.4±0.5; d3, 2.0±0.8; d4, 2.1±0.9; d5, 2.1±0.8; d6, 2.0±0.8; d7, 1.2±0.6. L↔H: d1, 2.7±0.7; d2, 2.6±0.6; d3, 0.9±0.2; d4, 0.9±0.3; d5, 0.9±0.1; d6, 1.0±0.4; d7, 1.9±0.7. 11/13 of U osm :P osm <1 values occurred for H↔L on d1, d2 and d7, and 32/33 occurred for L↔H on d3 to d6. Mean daily P osm values were similar (7d range: H↔L, 292 – 295; L↔H, 293 – 296 mOsm/kg), reflecting neuroendocrine regulation. These data indicate that U osm :P osm warrants further investigation as an index of human hydration status across days. Funded by Danone Research, France.