Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-10-27
pubmed:abstractText
1. Gender differences in fat oxidation at rest and during exercise may contribute to higher body fat in women. We examined gender differences in fat oxidation at rest and during submaximal exercise and their relationship to sympathetic nervous system activity, free fatty acid availability, body composition and aerobic capacity in older volunteers. 2. We measured free fatty acid kinetics using [14C]palmitate, absolute (micromol/min) and relative (respiratory quotient) rates of fat oxidation by indirect calorimetry and sympathetic nervous system activity from noradrenaline kinetics using [3H]noradrenaline in 12 older men (70+/-4 years) and 12 older women (66+/-4 years) at rest and during 30 min of submaximal exercise (45% of peak oxygen consumption). 3. At rest, men oxidized more fat than women on both an absolute (88+/-19 versus 51+/-15 micromol/min; P<0.01) and relative (respiratory quotient: 0.80+/-0. 04 versus 0.85+/-0.04; P<0.01) basis. These differences were not related to noradrenaline appearance rate, free fatty acid concentration, body composition or aerobic capacity. During exercise, fat oxidation was higher (P<0.05 to P<0.01) in men on an absolute level, but respiratory quotient did not differ. Higher absolute fat oxidation in men during exercise was explained by their higher absolute workload. Plasma free fatty acids and free fatty acid rate of appearance did not differ between men and women during exercise despite higher (P<0.05 to P<0.01) plasma noradrenaline concentrations in men. 4. We conclude that: (i) resting fat oxidation is higher in older men compared with older women independent of differences in noradrenaline appearance rate, free fatty acid availability, body composition or aerobic capacity, and (ii) despite higher plasma noradrenaline concentrations during submaximal exercise, no gender differences in free fatty acid appearance rate or fat oxidation were found. These results suggest a sex dimorphism in post-absorptive fat metabolism in the elderly.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0143-5221
pubmed:author
pubmed:issnType
Print
pubmed:volume
95
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
59-66
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Gender differences in fat oxidation and sympathetic nervous system activity at rest and during submaximal exercise in older individuals.
pubmed:affiliation
Division of Clinical Pharmacology and Metabolic Research, Department of Medicine, Given Building C-247, University of Vermont, Burlington, Vermont 05405, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.