title: VLDL-triglyceride kinetics during hyperglycemia-hyperinsulinemia: effects of sex and obesity.
abstract: We have previously shown that sex and obesity independently affect basal very low density lipoprotein (VLDL)-triglyceride (TG) kinetics. In the present study, we investigated the effect of hyperglycemia-hyperinsulinemia on VLDL-TG kinetics in lean and obese men and women (n = 6 in each group). VLDL-TG kinetics were measured during basal, postabsorptive conditions and during glucose infusion (5.5 mg x kg FFM(-1) x min(-1)) by using [(2)H(5)]glycerol bolus injection in conjunction with compartmental modeling analysis. Basal VLDL-TG secretion in plasma was greater in obese than in lean men (7.8 +/- 0.6 and 2.9 +/- 0.4 micromol x l plasma(-1) x min(-1); P < 0.001) but was not different in lean and obese women (5.0 +/- 1.1 and 5.9 +/- 1.1 micromol x l plasma(-1) x min(-1)). Glucose infusion decreased the VLDL-TG secretion rate by approximately 50% in lean and obese men and in lean women (to 1.5 +/- 0.4, 4.0 +/- 0.6, and 2.2 +/- 0.4 micromol x l plasma(-1) x min(-1), respectively; all P < 0.05) but had no effect on the VLDL-TG secretion rate in obese women (4.9 +/- 1.0 micromol x l plasma(-1) x min(-1)). These results demonstrate that both sex and adiposity affect the regulation of VLDL-TG metabolism. Glucose and insulin decrease VLDL-TG production in both lean men and lean women; obesity is associated with resistance to the glucose- and insulin-mediated suppression of VLDL-TG secretion in women, but not in men.
authors.affiliation: Department of Internal Medicine and Center for Human Nutrition, Washington University School of Medicine, St Louis, Missouri 63110, USA. mittendb@medicine.wustl.edu
authors.forename: Bettina
authors.initials: B
authors.lastname: Mittendorfer
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Patterson
authors.forename: Samuel
authors.initials: S
authors.lastname: Klein
authors.forename: Labros S
authors.initials: LS
authors.lastname: Sidossis
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015243:Cholesterol, VLDL / Q000097:blood*; D003327:Coronary Disease / Q000378:metabolism; D005227:Fatty Acids / Q000097:blood; D005260:Female; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism*; D006946:Hyperinsulinism / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007700:Kinetics; D008297:Male; D009765:Obesity / Q000378:metabolism*; D012737:Sex Factors; D014280:Triglycerides / Q000097:blood*
chemical_list: D001786:Blood Glucose; D015243:Cholesterol, VLDL; D005227:Fatty Acids; D007328:Insulin; D014280:Triglycerides; D005947:Glucose