The effect of storing temperature and duration on urinary hydration markers

J. D. Adams, Stavros A. Kavouras, Evan C. Johnson, Lisa T. Jansen, Catalina Capitan-Jimenez, Joseph I. Robillard, Andy Mauromoustakos

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

The purpose of this investigation was to quantify the effects of storage temperature, duration, and the urinary sediment on urinary hydration markers. Thirty-six human urine samples were analyzed fresh and then the remaining sample was separated into 24 separate vials, six in each of the following four temperatures: 22 °C, 7 °C, -20 °C, and -80 °C. Two of each sample stored in any given temperature, were analyzed after 1, 2, and 7 days either following vortexing or centrifugation. Each urine sample was analyzed for osmolality (UOsm), urine specific gravity (USG), and urine color (UC). UOsm was stable at 22 °C, for 1 day (+5-9 mmolkg-1, p > .05) and at 7 °C, UOsm up to 7 days (+8-8 mmolkg-1, p > .05). At -20 and -80 °C, UOsm decreased after 1, 2, and 7 days (9-61 mmolkg-1, p < .05). Vortexing the sample before analysis further decreased only UOsm in the -20 °C and -80 °C storage. USG remained stable up to 7 days when samples were stored in 22 °C or 7 °C (p > .05) but declined significantly when stored in -20 °C, and -80 °C (p < .001). UC was not stable in any of the storing conditions for 1, 2, and 7 days. In conclusion, these data indicate that urine specimens analyzed for UOsm or USG remained stable in refrigerated (7 °C) environment for up to 7 days, and in room temperature for 1 day. However, freezing (-20 and -80 °C) samples significantly decreased the values of hydration markers.

Original languageEnglish (US)
Pages (from-to)18-24
Number of pages7
JournalInternational Journal of Sport Nutrition and Exercise Metabolism
Volume27
Issue number1
DOIs
StatePublished - Feb 2017
Externally publishedYes

Keywords

  • Hydration indices
  • Urine color
  • Urine osmolality
  • Urine samples
  • Urine specific gravity

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Orthopedics and Sports Medicine
  • Nutrition and Dietetics

Fingerprint Dive into the research topics of 'The effect of storing temperature and duration on urinary hydration markers'. Together they form a unique fingerprint.

  • Cite this

    Adams, J. D., Kavouras, S. A., Johnson, E. C., Jansen, L. T., Capitan-Jimenez, C., Robillard, J. I., & Mauromoustakos, A. (2017). The effect of storing temperature and duration on urinary hydration markers. International Journal of Sport Nutrition and Exercise Metabolism, 27(1), 18-24. https://doi.org/10.1123/ijsnem.2016-0098