The effect of psychical stress on cause and exacerbation of diabetes mellitus, serum glucose and cortisol levels, and body weight in rats

In this study the effects of chronic stress on the serum glucose level (SGL), serum cortisol level (SCL) and body weight were investigated to determine the possible causal link between stress and diabetes. The experiments were performed on nondiabetic and diabetic rats divided to control, sham, and stressed groups. Water immersion was used as chronic psychical stress (one minute every hour, 4 hours every day for a period of 14 days). After the experiment, a blood sample was collected. The serum glucose level was measured by the glucose oxidase method, and serum cortisol level was measured by radioimmunoassay method. Difference in body weight was also calculated. Our results showed that, this psychical stress caused a significant increase in glucose level in both nondiabetic and diabetic rats, but could not produce diabetes in nondiabetic rats. Diabetes caused significant increase in serum cortisol level. This stress caused a small but nonsignificant increase of cortisol level. Also, there was a significant weight loss in stressed rats, that was much higher in diabetic rats. Effect of diabetes on weight loss was much higher than that of the psychical stress. Therefore stress exacerbated the disease in the diabetic rats and probably made the nondiabetic rats prone to diabetes.