Total body potassium in aging humans: a longitudinal study

Abstract

Total body potassium (TBK) data calculated from longitudinal measurements over 18 y of 40K by whole-body counting of 564 male and 61 female healthy humans in a 2-pi liquid scintillation counter show little change in females younger than 50 y compared with males of those ages. Males show less TBK from 41 y onward as they age, with most rapid rate of loss between 41 and 60 y. Females have a rapid loss of TBK when they are older than 60 y; the loss is at a greater rate than that of males. Percent total body fat calculated from total body weight and lean body mass (LBM) derived from TBK document greater adiposity in females at all ages except ages 51-60 y when females are similar to males in change in percent fat per year per centimeter.

The prevalence and risk factors for age-related macular degeneration in rural–urban India, Sankara Nethralaya Rural–Urban Age-related Macular degeneration study, Report No. 1

“…A key observation made by Krieger (36), and later more comprehensively-and tragically-by the Warsaw Ghetto investigators (37) and studies of patients with AIDS (38), is that humans do not survive once their BCM declines below approximately 60% of normal levels for young adults. Moreover, BCM declines steadily with age even in healthy, successfully ageing people (39,40).…”

Sarcopenia and its implications for the elderly

“…There was a decline in lean mass of 0.25 kgay over this time span. Flynn et al (1989) measured body cell mass by TBK at 2 y intervals over 18 y in a group of 564 male and 61 female faculty employees of the University of Missouri. Lean mass (calculated from TBK) declined in the men who were ®rst measured after age 40, with a median loss of 0.3 kgay.…”

Lipid metabolism in the elderly

“…Fat-free mass declines with age in both men and women (Brozek, 1952;Flynn et al, 1977;Poehlman et al, 1992;. Thus, it is plausible to hypothesize that the reduction in fat-free mass with age partially explains the decline in fat oxidation.…”