Aging, resting metabolic rate, and oxidative damage: results from the Louisiana Healthy Aging Study.
BACKGROUND
The aging process occurs at variable rates both among and within species and may be related to the variability in oxygen consumption and free radical production impacting oxidative stress. The current study was designed to test whether nonagenarians have a relatively low metabolic rate and whether it is associated with low levels of oxidative stress relative to age.


METHODS
Resting metabolic rate (RMR) and markers of oxidative stress to lipids, proteins, and DNA were measured in three groups of individuals aged 20-34 (n=47), 60-74 (n=49), and>or=90 years (n=74).


RESULTS
RMR, adjusted for fat-free mass, fat mass, and sex, was lower in both older groups when compared to the young group (p<or=.0001). There were no significant differences in urinary isoprostanes, serum protein carbonyls, or DNA fragmentation between groups, and RMR was not related to any markers of oxidative stress.


CONCLUSIONS
This study confirms an age-related decline in RMR independent of changes in body composition but surprisingly did not show an accumulation of oxidative damage with increasing age. Our data challenge the theory that RMR is a significant determinant of oxidative stress and therefore contributes to the aging process.
Frisard
Madlyn I
MI
Pennington Biomedical Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808, USA.
Broussard
Amanda
A
Davies
Sean S
SS
Roberts
L Jackson
LJ
Rood
Jennifer
J
de Jonge
Lillian
L
Fang
Xiaobing
X
Jazwinski
S Michal
SM
Deutsch
Walter A
WA
Ravussin
Eric
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001481:Basal Metabolism / Q000502:physiology*; D001823:Body Composition; D004247:DNA / Q000378:metabolism; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D011506:Proteins / Q000378:metabolism
D011506:Proteins; D004247:DNA