Effect of long-term high fat diet feeding on insulin resistance in rats

Objective To investigate the effect of long-term high fat diet feeding on insulin resistance(IR) in rats.Methods Male Wistar rats were randomly divided into two groups.Rats in control group were fed with routine diet and in high-fat group with high-fat diet(38.5% of calories-fat) for 12 weeks,and then switched to a diet containing 51.3% of calories-fat for 4 weeks.After 16 weeks,body weight,fasting blood glucose(FBG),fasting insulin(FINS),insulin sensitivity index(ISI) and homeostasis model assessment of insulin resistance(HOMA-IR) were measured.Oral glucose tolerance test(OGTT) was performed for valuing AUC of plasma glucose.Results Energy intake of high-fat group was similar to that of control group.High-fat group gained only 32.7 g more weight than that of control group.FINS concentration of high-fat group was significantly higher than that of control group,but there was no difference in FBG between two groups.In high-fat group,ISI was obviously lower and HOMA-IR was markedly higher than that of control group(P0.01).Furthermore,the AUC of plasma glucose was significantly higher in high-fat group than that of control group.Conclusions High fat diet feeding can induce IR and impair glucose tolerance.