HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Cited by other online articles Google Scholar Articles by Sehl, M. E. Articles by Yates, F. E. Articles citing this Article PubMed PubMed Citation Articles by Sehl, M. E. Articles by Yates, F. E.

Kinetics of Human Aging

I. Rates of Senescence Between Ages 30 and 70 Years in Healthy People

^a Division of Geriatrics, Department of Medicine, University of California School of Medicine, Los Angeles
^b Division of Biology and Medicine, Brown University School of Medicine, Providence, Rhode Island

Correspondence: F. Eugene Yates, Department of Medicine, UCLA, Medical Monitoring Unit, Suite 330, 1950 Sawtelle Blvd., Los Angeles, CA 90025-7014 E-mail: gyates{at}ix.netcom.com.

Decision Editor: John A. Faulkner, PhD

A calculation of loss rates is reported for human structural and functional variables from a substantially larger data set than has been previously studied. Data were collected for healthy, nonsmoking human subjects of both sexes from a literature search of cross-sectional, longitudinal, and cross-sequential studies. The number of studies analyzed was 469, and the total number of subjects was 54,274. A linear model provided a fit of the data, for each variable, that was not significantly different from the best polynomial fit. Therefore, linear loss rates (as a percent decline per year from the reference value at age 30) were calculated for 445 variables from 13 organ systems, and additionally for 24 variables even more integrative, such as maximum oxygen consumption and exercise performance, that express effects of multiple contributing variables and systems. The frequency distribution of the 13 individual system linear loss rates (as percent loss per year) for a very healthy population has roughly a unimodal, right-skewed shape, with mean 0.65, median 0.5, and variance 0.32. (The actual underlying distribution could be a truncated Gaussian, an exponential, Poisson, gamma or some other). The linear estimates of loss rates were clustered between 0% and 2% per year for variables from most organ systems, with exceptions being the endocrine, thermoregulatory, and gastrointestinal systems, for which wider ranges (up to 3% per year) of loss rates were found. We suggest that this set of linear losses over time, observed in healthy individuals between ages (approximately) 30 to 70 years, exposes the underlying kinetics of human senescence, independent of effects of substantial disease.

This article has been cited by other articles: (Search Google Scholar for Other Citing Articles)

				L. A. Gavrilov and N. S. Gavrilova The Quest for a General Theory of Aging and Longevity Sci. Aging Knowl. Environ., July 16, 2003; 2003(28): re5 - 5. [Abstract] [Full Text] [PDF]

				J. E. Morley and J. H. Flaherty Editorial It's Never Too Late: Health Promotion and Illness Prevention in Older Persons J. Gerontol. A Biol. Sci. Med. Sci., June 1, 2002; 57(6): M338 - 342. [Full Text]

				W. M. Bortz II Nonage Versus Age J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2001; 56(9): M527 - 528. [Full Text] [PDF]