THE VALIDITY OF URINE COLOR SELF-ASSESSMENT AS AN INDEX OF HYDRATION IN MALES

J.D. Adams, Layne Nixon, Cameron Nichols, & Stavros Kavouras, FACSM. University of Arkansas, Fayetteville, AR; e-mail: jxa014@uark.edu Urine color (UC) is a practical tool for hydration assessment. To date no study has found if the general population can accurately assess their UC. PURPOSE: Therefore, the purpose of this study was to examine the accuracy of self-assessed UC as an index of hydration in males. METHODS: Seventy six males (24±5 y; 83.9±16.0 kg; 1.79±0.76 m) participated in the study. Participants were instructed to provide a single void into a specially constructed urinal which drained into a dark, plastic urine container. Participants were asked to compare their urine to an eight-point color scale. Hydration status was assessed by an experienced technician via urine osmolality (UOsm) and UC via the eight-point and two-point color scales. RESULTS: Mean UC was 3±1 and UOsm 661±247 mmol/kg. UC displayed a positive relationship as a predictor of UOsm (R2 = 0.21; P \u3c 0.001). The diagnostic ability of self-assessed urine color for hydration state was assessed via receiver operating curve. A cut-off point of \u3c800 mmol/kg of urine osmolality was defined as hypohydration. UC had a poor overall diagnostic ability (area under the curve 65%), with excellent sensitivity (91%), and poor specificity (35%). Further threshold analysis indicated that the optimal self-assessed UC threshold for hypohydration was ≥3. CONCLUSION: Even though self-assessed UC had “poor” overall diagnostic ability for assessing hydration, the diagnosis of hypohydration with a UC of ≥3 was excellent, but assessing euhydration was inaccurate