Effects of chronic treatment with acarbose on glucose and lipid metabolismin obese diabetic Wistar rats

Aims: The effect of chronic treatment with acarbose on fasting plasma gluco se, insulin, triglyceride, cholesterol and free fatty acid (FFA) concentrat ions, as well as on the glucose and insulin excursions during oral glucose tolerance test (OGTT), in obese diabetic Wistar (WDF) rats was investigated . Methods: Forty-five mature male WDF rats were randomly distributed to one o f the three treatment groups (no acarbose, 20 mg and 40 mg of acarbose/100 g of chow, respectively). After 3.5, 7.5 and 11.5 months, animals were test ed for glucose tolerance by means of an OGTT, and their respective metaboli c profiles were determined. Control determinations were done in obese and a ge-matched lean animals before the start of the trial. Results: The WDF rats exhibit higher body weight and fasting blood glucose, insulin, triglyceride and cholesterol concentrations compared to lean anim als. Moreover, they show marked glucose intolerance as indicated by the glu cose and insulin excursions during OGTT. Interestingly, in both treated and untreated animals, a reversion of the hyperglycaemic state as well as an i mprovement of the glucose tolerance is observed. However, whereas in the gr oup receiving no acarbose this is accounted for by dramatic increases in fa sting plasma insulin concentrations and insulin secretion during OGTT (as i ndicated by the, Delta Insulin area), in rats treated with acarbose the rev ersion of the diabetic state takes place without increments in hormone conc entration. In addition, rats treated with acarbose for 3.5 and 7.5 months s how lower plasma triglyceride and FFA concentrations, and the same was obse rved for cholesterol at the highest dosage of the drug. Conclusions: Chronic treatment with acarbose of WDF rats improves the glyca emic and lipidic control as well as the glucose tolerance, with a lower dem and of pancreatic insulin than in untreated rats. This data suggests that t he long-term modulation of glucose and insulin excursions after meals impro ves the insulin sensitivity in this rat strain.