The relation of hydration status to declarative memory and working memory in older adults.

Abstract

Prior studies have suggested a relationship between dehydration and poor cognitive performance. The present study examined the relationships among hydration status, declarative memory and working memory skills, and blood pressure in a sample of older community dwelling females. Data was analyzed from a larger study; relationships among hydration status, blood pressure, and cognitive measures were assessed with correlation and meditational analyses. Laboratory. 21 postmenopausal women (mean age 60.3, SD 8.03). Hydration status was measured using bioelectrical impedance, baseline blood pressure was assessed using a Colin Pressmate, and cognition was examined using the Auditory Verbal Learning Test and Auditory Consonant Trigrams. Bioelectrical impedance total body water by weight was found to be related to working memory, r = .47, p = .04, and memory skills, r = .54, p = .01. Total body water by weight was also found to be related to diastolic blood pressure, r = -.56, p = .01, which in turn was related to working memory, r = -.67, p = .002, and declarative memory, r = -.57, p = .009, skills. When diastolic blood pressure was accounted for, the relationship between hydration status and cognitive skills was attenuated. A similar pattern of results was seen for systolic blood pressure, although findings did not reach statistical significance. Results emphasize the importance of considering hydration status and blood pressure when interpreting cognitive performance in older adults.