Effect of training and creatine supplementation interaction on insulin resistance and glucose tolerance in obese male rats

The present study was undertaken to explore the effects of exercise training and creatine supplementation interaction on insulin resistance and glucose tolerance in obese male rats.

50 male Wistar rats (weigh; 160 ± 15 g) were randomly divided into five groups. Control, High-fat Diet, High-Fat Diet plus creatine supplementation, High-Fat Diet plus exercise training and High-Fat Diet plus Creatine plus exercise training. Training program was 12 weeks swimming and each week its duration increased. At the end, rats underwent the glucose tolerance test (OGTT) and the blood samples for analyzing TG, HDL and insulin collected. Moreover, for determining of PGC-1α expression the SOL muscle dissected. 

Obesity resulted in increased insulin resistance level and it also reduced glucose tolerance and insulin efficiency; creatine supplementation alone did not affect these changes. Training reduced insulin resistance and also elevated glucose tolerance and insulin efficiency in high-fat fed rats and creatine supplementation combined with training had additive effect on these variables. High-fat diet reduced PGC-1α protein level and training elevated it. Creatine supplementation alone or combined with training did not change the expression of this protein (P < 0.05).

For the first time, this study shows that combined creatine supplementation with training resulted in improved glycemic control and insulin efficiency and it also reduced the insulin resistance of obese rats.