Hyperinsulinemia in fructose-induced hypertriglyceridemia in the rat

Rats were fed diets containing (as percent of calories) 66% glucose or fructose, 22% casein, and 12% lard, for 1 wk. The effects of these diets on plasma triglyceride, glucose, and insulin concentrations were compared to those of control rats eating regular rat chow. Plasma triglyceride levels increased from a mean (+/- SE) control level of 85 +/- 7 to 142 +/- 9 (p less than 0.001) and 380 +/- 38 (p less than 0.001) mg/dl in dextrose- and fructose-fed rats, respectively. Plasma insulin concentrations demonstrated a similar increase, rising from a mean (+/- SE) control value of 29 +/- 4 microunits/ml to 55 +/- 10 microunits/ml in dextrose-fed rats and 85 +/- 12 microunits/ml in rats eating the fructose diet. Plasma glucose concentrations of the three groups were comparable. These results indicate that fructose-induced hypertriglyceridemia is associated with significant hyperinsulinemia.