The influence of different exercises intensity on the level of serum leptin for STZ diabetic rats

Objective:To study if exercises can affect serum leptin level that related with weight regulation and observe the influence of different exercises intensity on weight, blood glucose, serum insulin and leptin in STZ diabetic rats. Method:Six experimental groups of rats were investigated: normal controls (NC), normal exercises (NE), diabetic group (DG), diabetic low-intensity exercises group (LEG), middle-intensity and great-intensity exercises group (MEG and GEG). Swimming training was administered according to Ploug methods. Result:After 8 weeks swimming, serum leptin concentration of NE markedly decreased. Before swimming, body weight, serum insulin and leptin level of all the STZ diabetic rats were significantly lower than that of NC, and blood glucose were higher. Eight weeks later, only rats of MEG raised an obvious increase in weight lift per week, concentration of blood glucose decreased 35%, serum insulin level increased 38%, serum leptin level increased 40%. However, 8 weeks later the former guidelines in LEG and GEG made no differences with those of pre-exercises. Multiple relation and stepwise regression analysis were applied. It indicated that in diabetic rats only serum insulin was a significant influencing factor of serum leptin. Conclusion:Under normal physiological condition decreased serum leptin level by exercises is an adaptive reaction to maintain stable body weight and balanceable energy, while under STZ diabetic condition, leptin seems to be closely related with insulin. Middle-intensity exercises reduce blood glucose and improve insulin sensitivity, and at the same time, it seems to improve leptin sensitivity. Insufficient exercises or excess exercises have no therapeutic effect on diabetes.