Document Type : Original Article
Assistant Professor, Department of Sport Sciences, Faculty of Social Sciences, Imam Khomeini International University, Qazvin, Iran
Master of exercise physiology, Allame Gazvini Institute, Qazvin, Iran
Assistant Professor, Department of exercise physiology, Faculty of Sport Sciences, Shahrood University of Technology, Shahrood, Iran
Background: Diabetes mellitus is a widespread disease disrupting cognitive function. We investigated the effect of eight-week high-intensity interval training (HIIT) and caffeine supplementation on Brain-derived neurotrophic factor (BDNF) and glial line-derived neurotrophic factor (GDNF) in a rat diabetic model.
Methods: In this experimental study, streptozotocin-induced diabetic rats were randomly divided into: control (C), diabetic (D), diabetic+caffeine (D+CA), diabetic+training (D+T) and diabetic+training+caffeine (D+T+CA) groups. Training groups underwent a high-intensity interval training program (5 sessions a week over 8 weeks). The supplement groups were administered with 7mg caffeine/100gr body weight for 5 days a week before each exercise session throughout the experimental period. The rat hippocampus and brainstem were removed 48 h after the last training session and blood samples were taken from left ventricle. The levels of glucose, BDNF and GDNF were measured by ELISA assay. Data were analyzed using two-way ANOVA test.
Results: Streptozotocin-induced diabetes increased blood glucose (p <0.01) whereas decreased BDNF and GDNF levels (P=0.002). The results showed that HIIT decreased blood glucose (P=0.002) but increased BDNF and GDNF levels in diabetic rats (P=0.003 and P=0.001, respectively). Even though caffeine supplementation significantly reduced blood glucose concentration (P=0.0001), it had no significant effect on BDNF and GDNF levels in diabetic rats (P>0.05). We also observed a significant interaction between treatments regarding GDNF changes (P=0.024); yet, the interaction between caffeine and HIIT on BDNF did not reach the significance level (P=0.074).
Conclusion: Based on the findings, HIIT increased BDNF and GDNF levels in rat diabetic model, but caffeine ingestion had no significant effect on neurotrophic factors. However, caffeine seems to blunt HIIT-induced increase in neurotrophic factors which remains to be further investigated.