Female rats do not develop sucrose-induced insulin resistance

In male rats, 2 wk of high-sucrose feeding results in insulin resistance and hypertriglyceridemia [Pagliassotti, M.J., P.A. Prach, T.A. Koppenhafer, and D.A. Pan. Am. J. Physiol. 271 (Regulatory Integrative Comp. Physiol. 40): R1319-R1326, 1996]. The present study aimed to determine if female rats also become insulin resistant and hypertriglyceridemic in response to high-sucrose feeding. Female Wistar rats (7 wk old) were fed either a high-sucrose diet (68% energy) (SU) or a high-starch diet (68% energy) (ST) for 3, 5, or 8 wk. In each animal, glucose kinetics were measured using [3-(3)H]glucose under basal and hyperinsulinemic conditions (insulin infusion 4.0 mU.kg-1.min-1). Body weight and basal glucose kinetics were not different between diet groups at 3, 5, or 8 wk. Glucose infusion rate (mg.kg-1.min-1) was not different between groups (3 wk: 17.7 +/- 1.6 ST, 16.6 +/- 0.9 SU; 5 wk: 16.1 +/- 0.9 ST, 15.1 +/- 2.0 SU; 8 wk: 18.3 +/- 1.9 ST, 16.1 +/- 1.5 SU). Clamp rate of glucose appearance (mg.kg-1.min-1) was also not different between diet groups (3 wk: 4.0 +/- 1.6 ST, 3.6 +/- 1.4 SU; 5 wk: 2.6 +/- 1.0 ST, 2.3 +/- 1.14 SU; 8 wk: 5.9 +/- 1.8 ST, 7.7 +/- 1.2 SU). No difference was observed in plasma and tissue triglycerides or tissue glycogen between sucrose- and starch-fed animals. We therefore conclude that female rats, in contrast to males, do not develop sucrose-induced insulin resistance and hypertriglyceridemia.