Premium
Body Water Spaces and Cellular Hydration during Healthy Aging
Author(s) -
RITZ P.
Publication year - 2000
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2000.tb06502.x
Subject(s) - body water , intracellular , dehydration , free water , dilution , extracellular fluid , chemistry , fat mass , intracellular fluid , body weight , fat free mass , zoology , lean body mass , fluid compartments , physiology , water mass , extracellular , bound water , fresh water , endocrinology , medicine , biochemistry , biology , thermodynamics , environmental engineering , oceanography , engineering , physics , fishery , geology , organic chemistry , molecule
A bstract : Age‐related changes in the proportions of intracellular or extracellular water to total body water and in the ratio of total body water to fat‐free mass are debatable. These are important issues both for medical reasons (dehydration is a threat in the diseased elderly) and for methodological reasons (most techniques for assessing of body composition assume constant hydration of the fat‐free mass). This study compared hydration in young and elderly (60 ears) people. In the first part of the study, we analyzed the literature and computed the ratio of total body water over fat‐free mass, Hf. Eligible studies involved independent measurements of fat‐free mass and total body water. Hf did not appear to change with age. The second part of this study computed Hf in 103 individuals studied in our laboratory. The mean values were not different in young (73.2 ± 2.4%) and elderly people (73.4 ± 2.4%). At all ages, the proportion of intracellular or extracellular water (as measured by bromide dilution) to total body water (as measured by oxygen 18 dilution) was similar. The same finding holds for the proportion of intracellular water to fat‐free mass. We conclude that hydration of fat‐free mass and cellular hydration are not affected in healthy aging.