title: Comparison of the effects of sucrose and fructose on insulin action and glucose tolerance.
abstract: The purpose of the present study was to determine whether fructose is the nutrient mediator of sucrose-induced insulin resistance and glucose intolerance. Toward this end, male rats were fed a purified starch diet (68% of total calories) for a 2-wk baseline period. After this, rats either remained on the starch (ST) diet or were switched to a sucrose (SU, 68% of total calories), fructose/glucose (F/G, 34/34% of total calories), or fructose/starch (F/ST, 34/34% of total calories) diet for 5 wk. Rats then underwent either an intravenous glucose tolerance test (n = 10/diet) or a euglycemic, hyperinsulinemic clamp (n = 8 or 9/diet). Incremental glucose and insulin areas under the curve in SU, F/G, and F/ST were on average 61 and 29% greater than ST, respectively, but not significantly different from one another. During clamps, glucose infusion rates (mg. kg(-1). min(-1)) required to maintain euglycemia were significantly lower (P < 0.05) in SU, F/G, and F/ST (13.4 +/- 0.9, 9. 5 +/- 1.7, 11.3 +/- 1.3, respectively) compared with ST (22.8 +/- 1. 1). Insulin suppression of glucose appearance (mg. kg(-1). min(-1)) was significantly lower (P < 0.05) in SU, F/G, and F/ST (5.6 +/- 0.5, 2.2 +/- 1.2, and 6.6 +/- 0.7, respectively) compared with ST (9.6 +/- 0.4). Insulin-stimulated glucose disappearance (mg. kg(-1). min(-1)) was significantly lower (P < 0.05) in SU, F/G, and F/ST (17. 9 +/- 0.6, 16.2 +/- 1.3, 15.3 +/- 1.8, respectively) compared with ST (24.7 +/- 1.2). These data suggest that fructose is the primary nutrient mediator of sucrose-induced insulin resistance and glucose intolerance.
authors.affiliation: Department of Kinesiology, University of Colorado at Boulder, Boulder, Colorado 80302, USA. jeffrey.thresher@asu.edu
authors.forename: J S
authors.initials: JS
authors.lastname: Thresher
authors.forename: D A
authors.initials: DA
authors.lastname: Podolin
authors.forename: Y
authors.initials: Y
authors.lastname: Wei
authors.forename: R S
authors.initials: RS
authors.lastname: Mazzeo
authors.forename: M J
authors.initials: MJ
authors.lastname: Pagliassotti
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology / Q000187:drug effects; D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D004040:Dietary Carbohydrates / Q000494:pharmacology; D019422:Dietary Sucrose / Q000494:pharmacology*; D005632:Fructose / Q000494:pharmacology*; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology; D006946:Hyperinsulinism; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology*; D007333:Insulin Resistance; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013213:Starch; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D019422:Dietary Sucrose; D007328:Insulin; D005632:Fructose; D013213:Starch