The effect of chronic psychological stress on carbohydrate metabolism in rat

Several studies have shown that stress has major effects on metabolism. There is also some evidence indicating that stress may induce diabetes mellitus. The present study has investigated the role of chronic psychological stress on carbohydrate metabolism in male Wistar rats (250 ± 50 g). Animals were divided into control and test groups (n = 8/group). Blood samples were obtained by tail snipping from fasted animals, then oral glucose tolerance test was performed on the 1st, 15th and 30th days of experimental period. Different restrainer stressors were used twice daily and to minimize habituation the sequence of the stressors were randomized during the experiment. Glucose concentration was measured by a glucose oxidase method. Results showed that fasting plasma glucose concentration in the control group did not significantly change during the experiment. On the other hand, in the test group fasting plasma glucose concentration increased on 15th (157 ± 5 mg%) and 30th (157 ± 4 mg%) days of experiment as compared to the 1st day (127 ± 8 mg%). The comparison of fasting plasma glucose concentration between control and test groups showed a significant rise on 30th day in the test group. Glucose tolerance test in the test group exhibited a significant reduction in glucose tolerance just on 15th day with respect to the 1st day. The comparison of plasma glucose concentration between the test and control group after performing glucose tolerance test showed no significant difference. In conclusion, the results of this study indicate that psychological stress may induce diabetes types I and II or at least can set a basis for the disease.