Equivalence of afternoon spot and 24-h urinary hydration biomarkers in free-living healthy adults.

ABSTRACT:

Background/objectives

Urinary biomarkers of hydration (urine osmolality, UOsm; urine specific gravity, USG) follow circadian variations. For individuals, researchers and health-care professionals, there is value in identifying time frames during which spot values of UOsm and USG are representative of 24-h values in healthy young adults.

Subjects/methods

Eighty-two free-living adults (22.3±2.9 years, 22.2±1.5 kg/m(2)) collected individual urine voids over a 24-h period. UOsm and USG were measured on each void and on the pooled 24-h sample. To determine the time of day when a spot sample was likely to be equivalent to the 24-h value, daytime voids were binned by time and equivalence was tested for each 2-h window. Equivalence was a priori defined as being within 100 mOsm/kg (U

SUBMITTER: Bottin JH 

PROVIDER: S-EPMC5399132 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature