title: Energy expenditure, insulin, and VLDL-triglyceride production in humans.
abstract: Hypertriglyceridemia is considered a cardiovascular risk factor in diabetic and nondiabetic subjects. In this study, we aimed to determine potential regulators of very low density lipoprotein-triglyceride (TG) production. VLDL-TG kinetics were measured in 13 men and 12 women [body mass index [mean (range)]: 24.8 (20.2-35.6) kg/m(2)]. VLDL-TG production was assessed from the plasma decay of a bolus injection of ex vivo labeled VLDL particles ([1-(14)C]triolein-VLDL-TG). Similar VLDL-TG production (micromol/min) was found in men and women. VLDL-TG production was not significantly correlated with palmitate flux ([9,10-(3)H]palmitate) (r = 0.09, P = 0.67) or palmitate concentration (r = -0.29, P = 0.2) but was correlated significantly with fasting insulin concentration (r = 0.46, P < 0.05) and resting energy expenditure (REE) (r = 0.45, P < 0.05). The latter correlation improved when adjusted for sex. The best multivariate model with VLDL-TG production as the dependent variable and REE, body composition, hormones, and substrate levels as independent variables included fasting insulin (P = 0.02) and REE (P = 0.02) (r(2) = 0.32, P < 0.001). We conclude that VLDL kinetics are similar in men and women and that REE and plasma insulin are significant independent predictors of VLDL-TG production. FFA availability and body fat distribution are unrelated to VLDL production. We suggest that REE plays a greater role in VLDL-TG production than previously anticipated. REE and insulin should be taken into account when VLDL-TG production comparisons between groups are made.
authors.affiliation: Medical Department M (Endocrinology and Diabetes), Aarhus University Hospital, DK-8000 Aarhus, Denmark.
authors.forename: Lars C
authors.initials: LC
authors.lastname: Gormsen
authors.forename: Michael D
authors.initials: MD
authors.lastname: Jensen
authors.forename: Ole
authors.initials: O
authors.lastname: Schmitz
authors.forename: Niels
authors.initials: N
authors.lastname: Møller
authors.forename: Jens S
authors.initials: JS
authors.lastname: Christiansen
authors.forename: Søren
authors.initials: S
authors.lastname: Nielsen
mesh_terms: D001823:Body Composition; D015992:Body Mass Index; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood*; D007700:Kinetics; D008079:Lipoproteins, VLDL / Q000096:biosynthesis* / Q000097:blood*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D014280:Triglycerides / Q000096:biosynthesis* / Q000097:blood*
chemical_list: D007328:Insulin; D008079:Lipoproteins, VLDL; D014280:Triglycerides; C030106:very low density lipoprotein triglyceride; D019382:Human Growth Hormone; D009638:Norepinephrine