Relationships between Morning and Afternoon WUT (Weight, Urine Color, and Thirst) Criteria and Hydration Markers

Authors

Marcos S. Keefe, Texas Tech UniversityFollow
Jan-Joseph S. Rolloque, Texas Tech UniversityFollow
Nigel C. Jiwan, Texas Tech UniversityFollow
Casey R. Appell, Texas Tech UniversityFollow
Tyler McCollum, Texas Tech UniversityFollow
Hui-Ying Luk, Texas Tech UniversityFollow
Yasuki Sekiguchi, Texas Tech UniversityFollow

Abstract

A Venn diagram decision tool consisting of weight, urine color, and thirst (WUT) is suggested to measure hydration status. The WUT Venn diagram has been used as a practical hydration status assessment tool; however, this relationship has only been investigated using a first-morning urine sample. PURPOSE: To investigate relationships between morning and afternoon WUT criteria, blood and urine markers. METHODS: Eight men (age: 21 ± 3; mass: 76.3 ± 15.6 kg) and five women (age: 22 ± 2; mass: 60.5 ± 13.6 kg) completed the study. Body mass, urine color, urine specific gravity (USG), urine osmolality (U_OSM), thirst level, and plasma osmolality (P_OSM) were collected as a first-morning and afternoon spot urine (2:00-4:00 CST) for 3 consecutive days in a free-living situation and 3 consecutive days in a euhydrated state. Body mass loss >1%, urine color >5, and thirst level ≥5 were used as dehydration thresholds. The number of markers that indicated dehydration levels were counted and categorized into either 3, 2, 1, or 0 WUT markers indicating dehydration (defined by either USG, U_OSM, or P_OSM). One-way ANOVA with Tukey pairwise comparisons were used to assess differences in USG, U_OSM, and P_OSM between different numbers of WUT markers. Receiver operating characteristics analysis was performed to calculate the predictive value of 0, 1, 2, or 3 hydration markers in detecting a dehydrated or euhydrated state. RESULTS: Morning and afternoon 1, 2, and 3 WUT markers were not significantly different (ps > .05) for USG and P_OSM. Morning and afternoon 0, 2, and 3 WUT markers were not significantly different for U_OSM. Morning and afternoon 3 WUT resulted in a specificity of 0.984 and 1.000, 0.984 and 1.000, and 0.956 and 0.981 for USG > 1.020, U_OSM > 700mOsm, and P_OSM > 290mOsm, respectively. Meeting at 2 WUT for morning and afternoon resulted in a specificity of 0.820 and 0.985, and 0.806 and 0.984 for USG and U_OSM, respectively. Meeting at 1 WUT for morning and afternoon resulted in a sensitivity of 1.000 and 0.813 for U_OSM. CONCLUSION: These results suggest that when 2 or 3 WUT markers are met, urine and blood hydration markers indicate dehydration, and when 1 WUT marker is met, U_OSM indicates not dehydrated. The WUT Venn diagram can assess hydration status when an afternoon spot urine sample is used.

Recommended Citation

Keefe, Marcos S.; Rolloque, Jan-Joseph S.; Jiwan, Nigel C.; Appell, Casey R.; McCollum, Tyler; Luk, Hui-Ying; and Sekiguchi, Yasuki (2023) "Relationships between Morning and Afternoon WUT (Weight, Urine Color, and Thirst) Criteria and Hydration Markers," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 15, Article 13.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss15/13