The Effect of HighIntensity Interval Training (HIIT) and Caffeine Supplementation on Brainderived Neurotrophic Factor and Glial Linederived Neurotrophic Factor in StreptozotocinInduced Diabetic Rats

Background: Diabetes mellitus is a widespread disease disrupting cognitive function. We investigated the effect of eightweek highintensity interval training (HIIT) and caffeine supplementation on Brainderived neurotrophic factor (BDNF) and glial linederived neurotrophic factor (GDNF) in a rat diabetic model. Methods: lt;/strong gt; In this experimental study, streptozotocininduced 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 highintensity 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 twoway ANOVA test. Results: lt;/strong gt; Streptozotocininduced diabetes increased blood glucose (P lt;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 gt;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: lt;/strong gt; 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 HIITinduced increase in neurotrophic factors which remains to be further investigated.