Aerobic exercise ameliorates glycemic control by improving the beta cell function and independent of insulin resistance in diabetic rats

Improving glycemic profile in diabetics is rooted in several metabolic, hormonal and genetic factors. The aim of this study was to determine the effect of aerobic training on blood glucose levels in diabetic rats with emphasis on insulin resistance and beta cell function.

For this purpose, 14 male Wistar rats were divided into aerobic training (10 weeks, 5 session/weekly in the form of running on a treadmill, n = 7) and control (n = 7) groups after induction of type 2 diabetes by intraperitoneal injection of nicotinamide and Streptozotocin (STZ). Fasting glucose, serum insulin, insulin resistance and beta cell function of both groups were measured after lasted exercise session and compared between 2 groups by independent T test at a significant alpha level of less than 5%.

Despite no change in insulin resistance (P = 0.458), aerobic training resulted in significant decrease in fasting glucose (P <0.001) with increased serum insulin (P <0.001) and beta cell function (0.011) compared with control subjects.

Despite no change in insulin function in the target tissue, the improvement in glycemic profile of type 2 diabetic rats in response to aerobic training may be attributed to increased synthesis or secretion of insulin, or in other words, increased beta cell function. Understanding the mechanisms responsible for altering insulin function at cellular levels in response to exercise requires further studies in this area.