The Effect of Exercise Training Modality on Serum Brain Derived Neurotrophic Factor Levels in Individuals with Type 2 Diabetes

INTRODUCTION Brain derived neurotrophic factor (BDNF) has been implicated in memory, learning, and neurodegenerative diseases. However, the relationship of BDNF with cardiometabolic risk factors is unclear, and the effect of exercise training on BDNF has not been previously explored in individuals with type 2 diabetes. METHODS Men and women (N = 150) with type 2 diabetes were randomized to an aerobic exercise (aerobic), resistance exercise (resistance), or a combination of both (combination) for 9 months. Serum BDNF levels were evaluated at baseline and follow-up from archived blood samples. RESULTS Baseline serum BDNF was not associated with fitness, body composition, anthropometry, glucose control, or strength measures (all, p>0.05). Similarly, no significant change in serum BDNF levels was observed following exercise training in the aerobic (-1649.4 pg/ml, CI: -4768.9 to 1470.2), resistance (-2351.2 pg/ml, CI:-5290.7 to 588.3), or combination groups (-827.4 pg/ml, CI: -3533.3 to 1878.5) compared to the control group (-2320.0 pg/ml, CI: -5750.8 to 1110.8). However, reductions in waist circumference were directly associated with changes in serum BDNF following training (r = 0.25, p = 0.005). CONCLUSIONS Serum BDNF was not associated with fitness, body composition, anthropometry, glucose control, or strength measures at baseline. Likewise, serum BDNF measures were not altered by 9 months of aerobic, resistance, or combination training. However, reductions in waist circumference were associated with decreased serum BDNF levels. Future studies should investigate the relevance of BDNF with measures of cognitive function specifically in individuals with type-2 diabetes.