title: Sex differences in lipid and glucose kinetics after ingestion of an acute oral fructose load.
abstract: The increase in VLDL TAG concentration after ingestion of a high-fructose diet is more pronounced in men than in pre-menopausal women. We hypothesised that this may be due to a lower fructose-induced stimulation of de novo lipogenesis (DNL) in pre-menopausal women. To evaluate this hypothesis, nine healthy male and nine healthy female subjects were studied after ingestion of oral loads of fructose enriched with 13C6 fructose. Incorporation of 13C into breath CO2, plasma glucose and plasma VLDL palmitate was monitored to evaluate total fructose oxidation, gluconeogenesis and hepatic DNL, respectively. Substrate oxidation was assessed by indirect calorimetry. After 13C fructose ingestion, 44.0 (sd 3.2)% of labelled carbons were recovered in plasma glucose in males v. 41.9 (sd 2.3)% in females (NS), and 42.9 (sd 3.7)% of labelled carbons were recovered in breath CO2 in males v. 43.0 (sd 4.5)% in females (NS), indicating similar gluconeogenesis from fructose and total fructose oxidation in males and females. The area under the curve for 13C VLDL palmitate tracer-to-tracee ratio was four times lower in females (P < 0.05), indicating a lower DNL. Furthermore, lipid oxidation was significantly suppressed in males (by 16.4 (sd 5.2), P < 0.05), but it was not suppressed in females ( -1.3 (sd 4.7)%). These results support the hypothesis that females may be protected against fructose-induced hypertriglyceridaemia because of a lower stimulation of DNL and a lower suppression of lipid oxidation.
authors.affiliation: Faculty of Biology and Medicine, Department of Physiology, University of Lausanne, Rue du Bugnon 7, Lausanne CH-1005, Switzerland.
authors.forename: Christel
authors.initials: C
authors.lastname: Tran
authors.forename: Delphine
authors.initials: D
authors.lastname: Jacot-Descombes
authors.forename: Virgile
authors.initials: V
authors.lastname: Lecoultre
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Fielding
authors.forename: Guillaume
authors.initials: G
authors.lastname: Carrel
authors.forename: Kim-Anne
authors.initials: KA
authors.lastname: Lê
authors.forename: Philippe
authors.initials: P
authors.lastname: Schneiter
authors.forename: Muriel
authors.initials: M
authors.lastname: Bortolotti
authors.forename: Keith N
authors.initials: KN
authors.lastname: Frayn
authors.forename: Luc
authors.initials: L
authors.lastname: Tappy
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism; D002247:Carbon Isotopes; D005260:Female; D005632:Fructose / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D050356:Lipid Metabolism; D015227:Lipid Peroxidation; D008297:Male; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes; D005632:Fructose; D002244:Carbon