Białecka-Dębek Agata, Madej Dawid, Łojek Emilia
Department of Human Nutrition, Institute of Human Nutrition Sciences, Warsaw University of Life Sciences - SGGW, Warsaw, Poland.
Faculty of Psychology, University of Warsaw, Warsaw, Poland.
Eur J Nutr. 2025 May 9;64(4):175. doi: 10.1007/s00394-025-03690-1.
This study aimed to assess the relationship between the hydration status and cognitive functioning of older adults. The novelty of the study was the simultaneous use of several indicators of hydration status, including plasma and urine osmolality, specific gravity and urine color, as well as the assessment of total body water content from body composition measurements, together with comprehensive cognitive assessment.
A cross-sectional pilot study included 35 participants aged ≥ 60 years. Water intake was assessed using the 3-day food record method. Hydration status was assessed by plasma osmolality (Posm), urine osmolality (Uosm), specific gravity (USG) and color (UC), extracellular water (ECW) and percentage of total body water (%TBW). Cognitive functions were assessed using a set of standardized neuropsychological tests including: two verbal tests (Digit Span, DS and Vocabulary, VT) from the Wechsler Adult Intelligence Scale, California Verbal Learning Test (CVLT), Verbal Fluency Test (VFT), Grooved Pegboard Test (GPT) and Global Cognitive Function (GCF).
The %TBW was the most strongly related to cognitive processes of all the measures of hydration status. %TBW was significantly related to the performance on memory/learning based on CVLT (r = -0.55, p = 0.002), after a short delay (r = -0.59, p = 0.001) and long delay (r = -0.57, p = 0.001) and GCF (r = -0.43, p = 0.019). Marked correlations were also present between %TBW and psychomotor speed using the GPT (r = 0.41, p = 0.028). Moreover, significant relationships were obtained in cluster analyses. Cluster 2 (lower hydration status) was characterized by lower water intake and AI% (% of Adequate Intake), higher Uosm, USG, UC, ECW and %TBC than cluster 1. At the same time, it had significantly higher scores for language ability: VT (p = 0.041) and VFT (p = 0.041).
Significant relationships between some indicators of hydration status and selected cognitive domains were observed. This pilot study complements previous research on the relationship between hydration status and cognitive function in older adults, emphasizing that even small changes in hydration status assessment parameters can affect cognitive outcomes. In healthy, free-living older adults without dehydration assessed by plasma osmolality, other parameters of hydration status, such as water intake and urine parameters, influence language functions, suggesting the need to assess multiple markers simultaneously. The long-term effect of low water intake should be evaluated in a larger study group.
本研究旨在评估老年人的水合状态与认知功能之间的关系。该研究的新颖之处在于同时使用多种水合状态指标，包括血浆和尿液渗透压、比重和尿液颜色，以及通过身体成分测量评估总体水含量，并进行全面的认知评估。
一项横断面试点研究纳入了35名年龄≥60岁的参与者。采用3天食物记录法评估水摄入量。通过血浆渗透压（Posm）、尿液渗透压（Uosm）、比重（USG）和颜色（UC）、细胞外水（ECW）和总体水百分比（%TBW）评估水合状态。使用一组标准化神经心理测试评估认知功能，包括：韦氏成人智力量表中的两项言语测试（数字广度，DS和词汇，VT）、加利福尼亚言语学习测试（CVLT）、言语流畅性测试（VFT）、沟槽钉板测试（GPT）和整体认知功能（GCF）。
在所有水合状态测量指标中，%TBW与认知过程的相关性最强。%TBW与基于CVLT的记忆/学习表现显著相关（r = -0.55，p = 0.002），短延迟后（r = -0.59，p = 0.001）和长延迟后（r = -0.57，p = 0.001）以及GCF（r = -0.43，p = 0.019）。使用GPT评估时，%TBW与心理运动速度之间也存在显著相关性（r = 0.41，p = 0.028）。此外，在聚类分析中获得了显著关系。聚类2（水合状态较低）的特征是水摄入量和充足摄入量百分比（AI%）较低，Uosm、USG、UC、ECW和%TBC较高，高于聚类1。同时，其语言能力得分显著更高：VT（p = 0.041）和VFT（p = 0.041）。
观察到水合状态的一些指标与选定的认知领域之间存在显著关系。这项试点研究补充了先前关于老年人水合状态与认知功能关系的研究，强调即使水合状态评估参数的微小变化也可能影响认知结果。在通过血浆渗透压评估无脱水的健康、自由生活的老年人中，水合状态的其他参数，如水摄入量和尿液参数，会影响语言功能，这表明需要同时评估多个标志物。应在更大的研究组中评估低水摄入量的长期影响。
