Abstract
Dietary factors, especially fat composition, influence the progression of insulin resistance and metabolic disorders. Using a rat model of type II diabetes (Otsuka Long-Evans Tokushima Fatty (OLETF)), we examined the effects of fatty acid composition on insulin-mediated whole-body glucose uptake using hyperinsulinemic euglycemic clamp technique. Rats were fed powdered chow (5.1% fat) with the addition of 1.0g/kg/day of eicosapentaenoic-(94% eicosapentaenoic acid, EPA) or oleic-rich (79% oleic acid, OA) oils from 5 weeks until 30 weeks of age. EPA-rich diet, but not the OA-rich diet, significantly improved insulin sensitivity and decreased concentrations of plasma and liver lipids and abdominal fat deposition. Whole body insulin sensitivity was significantly inversely correlated with plasma triglyceride levels. Oral glucose tolerance test tended to be improved in the EPA group compared to that in the other two groups, although the difference was not significant. These results indicate that long-term feeding of EPA, but not with OA, may have a beneficial effect on insulin sensitivity in type II diabetes mellitus.
