Zhang Na, Du Songming, Zheng Mengqi, Tang Zhenchuang, Yan Ruixia, Zhu Yitang, Ma Guansheng
National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Xi Cheng District, Beijing, China.
Chinese Nutrition Society, Xi Cheng District, Beijing, China.
Asia Pac J Clin Nutr. 2017;26(5):788-793. doi: 10.6133/apjcn.052017.09.
To examine the association between quantified urine color and urine osmolality, and its validity in distinguishing hydration status among college men in Hebei, China.
Sixty-eight college men aged 18~25 years completed a cross-sectional study. All participants were asked to complete a 24-h fluid intake record to estimate fluid intake from beverages after anthropometric measurements. The foods eaten by participants were weighed to assess fluid intake from foods. All urine samples for the day were collected by participants to determine urine osmolality and urine color by chromatogram spectrophotometry (in accord with the Commission Internationale de l'Eclarige (CIE) notation Lab*).
A total 413 urine samples from 68 participants were collected and 151 (36.6%) samples indicated dehydration according to urine osmolality. The dehydrated group versus hydrated group had a smaller urine color L* (94.88 vs 98.06) and a* (- 2.39 vs -1.91), bigger b* (30.41 vs 15.15), and higher osmolality (958 mOsm/kg vs 486 mOsm/kg). Urine color and osmolality were closely correlated, especially for b* (0.86, p<0.0001). The percentage variance in urine osmolality (R2) explained by a partial least squares (PLS) model was 79%. Urine color b* contributed most substantially to the PLS model, with variable importance for projection of 1.35. The cutoff for b* for adequate hydration was 17.78 (area under the curve=0.899).
Differences in urine color between dehydrated and hydrated status related to urine osmolality. Urine color quantification is a reliable method to assess hydration status among young Chinese men.
研究尿液颜色量化值与尿渗透压之间的关联，及其在中国河北高校男性中区分水合状态的有效性。
68名年龄在18至25岁的高校男性完成了一项横断面研究。所有参与者在进行人体测量后，被要求完成一份24小时液体摄入量记录，以估算从饮料中摄入的液体量。对参与者所吃食物进行称重，以评估从食物中摄入的液体量。参与者收集当天所有尿液样本，通过色谱分光光度法（符合国际照明委员会（CIE）的Lab*表示法）测定尿渗透压和尿液颜色。
共收集了68名参与者的413份尿液样本，根据尿渗透压，151份（36.6%）样本显示脱水。脱水组与水合组相比，尿液颜色的L值较小（94.88对98.06），a值较小（-2.39对-1.91），b值较大（30.41对15.15），渗透压较高（958毫摩尔/千克对486毫摩尔/千克）。尿液颜色与渗透压密切相关，尤其是b值（0.86，p<0.0001）。偏最小二乘法（PLS）模型解释的尿渗透压变异百分比（R2）为79%。尿液颜色b对PLS模型的贡献最大，投影变量重要性为1.35。充足水合状态下b的临界值为17.78（曲线下面积=0.899）。
脱水状态与水合状态之间的尿液颜色差异与尿渗透压有关。尿液颜色量化是评估中国年轻男性水合状态的可靠方法。
