Young women partition fatty acids towards ketone body production rather than VLDL-TAG synthesis, compared with young men.
Journal article, 2011
Before the menopause, women are relatively protected against CVD compared with men. The reasons for this sex difference are not completely understood, but hepatic fatty acid metabolism may play a role. The present study aimed to investigate the utilisation of plasma NEFA by the liver and to determine whether they are partitioned differently into ketone bodies and VLDL-TAG in healthy, lean young men and women. Volunteers were studied during a prolonged overnight fast (12-19 h) using an intravenous infusion of [U-¹³C]palmitate. After 12 h fasting, the women had a more advantageous metabolic profile with lower plasma glucose (P < 0·05) and TAG (P < 0·05) but higher plasma NEFA (P < 0·05) concentrations. Plasma 3-hydroxybutyrate (3-OHB) concentrations rose more in women than in men, and the transfer of ¹³C from [U-¹³C]palmitate to plasma [¹³C]3-OHB reached a plateau 6-7 h after the start of the infusion in women but was still increasing at 6 h in men. This implies a slower 3-OHB production rate and/or dilution by other precursor pools in men. In women, the high isotopic enrichment of plasma 3-OHB suggested that systemic plasma fatty acids were the major source of 3-OHB production. However, in men, this was not observed during the course of the study (P < 0·01). There were no sex differences for the incorporation of ¹³C into VLDL1- or VLDL2-TAG. The ability of young women to partition fatty acids towards ketone body production rather than VLDL-TAG may contribute to their more advantageous metabolic profile compared with young men.
Sex Factors
Palmitic Acid
metabolism
metabolism
metabolism
Nonesterified
3-Hydroxybutyric Acid
physiology
metabolism
Adult
Postprandial Period
blood
VLDL
Fasting
Young Adult
Carbon Isotopes
Dietary Fats
Female
blood
Triglycerides
Lipoproteins
Liver
metabolism
blood
Male
blood
blood
Premenopause
Humans
Fatty Acids
Blood Glucose
physiology
Author
Kyriakoula Marinou
Martin Adiels
Chalmers, Mathematical Sciences
University of Gothenburg
Leanne Hodson
Keith N Frayn
Fredrik Karpe
Barbara A Fielding
British Journal of Nutrition
0007-1145 (ISSN) 1475-2662 (eISSN)
Vol. 105 6 857-65Subject Categories
MEDICAL AND HEALTH SCIENCES
DOI
10.1017/S0007114510004472
PubMed
21251339