TY - JOUR
T1 - Effects of aging on basal fat oxidation in obese humans
AU - Solomon, Thomas P.J.
AU - Marchetti, Christine M.
AU - Krishnan, Raj K.
AU - Gonzalez, Frank
AU - Kirwan, John P.
N1 - Funding Information:
We wish to thank the nursing/dietary staff of the General Clinical Research Center and the research participants for their cooperation and commitment. This research was supported by National Institutes of Health grants AG12834, RR10732, RR00080, and RR018390 and the Diabetes Association of Greater Cleveland (467-R-01).
PY - 2008/8
Y1 - 2008/8
N2 - Basal fat oxidation decreases with age. In obesity, it is not known whether this age-related process occurs independently of changes in body composition and insulin sensitivity. Therefore, body composition, resting energy expenditure, basal substrate oxidation, and maximal oxygen consumption (VO2max) were measured in 10 older (age, 60 ± 4 years; mean ± SEM) and 10 younger (age, 35 ± 4 years) body mass index-matched, obese, normal glucose-tolerant individuals. Fasting blood samples were also collected. Older subjects had slightly elevated fat mass (32.2 ± 7.1 vs 36.5 ± 6.7 kg, P = .16); however, waist circumference was not different between groups (104.3 ± 10.3 vs 102.1 ± 12.6 cm, P = .65). Basal fat oxidation was 22% lower (1.42 ± 0.14 vs 1.17 ± 0.22 mg/kg fat-free mass per minute, P = .03) in older subjects. The VO2max was also decreased in older individuals (44.6 ± 7.1 vs 38.3 ± 6.0 mL/kg fat-free mass per minute, P = .03); but insulin sensitivity, lipemia, and leptinemia were not different between groups (P > .05). Fat oxidation was most related to age (r = -0.61, P = .003) and VO2max (r = 0.52, P = .01). These data suggest that aging per se is responsible for reduced basal fat oxidation and maximal oxidative capacity in older obese individuals, independent of changes in insulin resistance, body mass, and abdominal fat. This indicates that age, in addition to obesity, is an independent risk factor for weight gain and for the metabolic complications of elevated body fat.
AB - Basal fat oxidation decreases with age. In obesity, it is not known whether this age-related process occurs independently of changes in body composition and insulin sensitivity. Therefore, body composition, resting energy expenditure, basal substrate oxidation, and maximal oxygen consumption (VO2max) were measured in 10 older (age, 60 ± 4 years; mean ± SEM) and 10 younger (age, 35 ± 4 years) body mass index-matched, obese, normal glucose-tolerant individuals. Fasting blood samples were also collected. Older subjects had slightly elevated fat mass (32.2 ± 7.1 vs 36.5 ± 6.7 kg, P = .16); however, waist circumference was not different between groups (104.3 ± 10.3 vs 102.1 ± 12.6 cm, P = .65). Basal fat oxidation was 22% lower (1.42 ± 0.14 vs 1.17 ± 0.22 mg/kg fat-free mass per minute, P = .03) in older subjects. The VO2max was also decreased in older individuals (44.6 ± 7.1 vs 38.3 ± 6.0 mL/kg fat-free mass per minute, P = .03); but insulin sensitivity, lipemia, and leptinemia were not different between groups (P > .05). Fat oxidation was most related to age (r = -0.61, P = .003) and VO2max (r = 0.52, P = .01). These data suggest that aging per se is responsible for reduced basal fat oxidation and maximal oxidative capacity in older obese individuals, independent of changes in insulin resistance, body mass, and abdominal fat. This indicates that age, in addition to obesity, is an independent risk factor for weight gain and for the metabolic complications of elevated body fat.
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U2 - 10.1016/j.metabol.2008.03.021
DO - 10.1016/j.metabol.2008.03.021
M3 - Article
C2 - 18640394
AN - SCOPUS:47149104321
SN - 0026-0495
VL - 57
SP - 1141
EP - 1147
JO - Metabolism: Clinical and Experimental
JF - Metabolism: Clinical and Experimental
IS - 8
ER -
