Sexual dimorphism of hyperglycemia and glucose tolerance in Wistar fatty rats

Obese and lean male and female Wistar fatty rats were fed a high-sucrose (68% of calories) diet from 5 to 22 wk of age. Obese males, but not obese females, developed hyperglycemia in the fed state and were more glucose intolerant during an intragastric glucose tolerance test than obese females. Lean Wistar fatty rats did not become hyperglycemic on the sucrose diet. Obese males also showed a smaller insulin response during the glucose tolerance test than did obese females. The Wistar fatty rat is a sexually dimorphic model of non-insulin-dependent diabetes mellitus in which the male but not the female obese rats become diabetic. The diabetic condition and impaired glucose tolerance in the obese male Wistar fatty rat may be related to impaired pancreatic insulin release and peripheral insulin resistance.