On the associations of body cholesterol pool size with age, HDL cholesterol and plasma total cholesterol concentration in humans.
Data from 17 subjects, in whom cholesterol kinetics had been measured by two-pool analysis of medium-term plasma cholesterol specific activity-time curves, were examined by multiple linear regression to explore the determinants of the size of the slowly exchanging cholesterol pool (MBmin) in humans. Pool size was independently and positively related to body weight (regression coefficient, 0.94 g per kg; P = 0.05) and age (1.77 g per year; P = 0.02). After allowance for these effects, MBmin retained a significant negative association with the plasma high density lipoprotein (HDL) cholesterol concentration (-0.56 g per mg/dl; P = 0.03), but was unrelated to plasma total cholesterol. This result is consistent with published data on the composition of those human tissues whose cholesterol is known to be largely a component of the slowly exchanging pool. It differs, however, from that of a recent study of cholesterol turnover [Blum et al, J. Lipid Res., 1985; 26: 1079-1088] in which pool size, measured by three-pool analysis of long-term decay curves, was unrelated to HDL and directly related to plasma total cholesterol. On the basis of other published data, it is considered that this discrepancy is unlikely to be a consequence of the difference between our respective studies in the duration and method of analysis of the specific activity decay curves. Differences in the variances of HDL cholesterol and plasma total cholesterol concentration that were examined, and in the biochemical-genetic factors underlying these variances, provide a more likely explanation. The overall weight of evidence favours the view that the pool of slowly exchangeable cholesterol in many human tissues expands during ageing at a rate which is increased in the presence of severe hypercholesterolemia, and which under some, but not all, circumstances also varies inversely with HDL cholesterol. The critical components of HDL metabolism which affect this process remain to be identified.
Miller
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Department of Chemical Pathology and Metabolic Disorders, St. Thomas' Campus, United Medical School, Guy's Thomas' Hospital, London, U.K.
D000328:Adult; D000375:Aging / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000378:metabolism*; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged
D008076:Cholesterol, HDL; D002784:Cholesterol