Combined exercise training-induced improvements in executive functions are related to baseline plasmatic levels of Brain-Derived Neurotrophic Factor (BDNF) in middle-aged adults and older with Type 2 Diabetes Mellitus

Abstract

\n Background: Type 2 Diabetes Mellitus (T2DM) affects many cognitive functions and aerobic plus resistance exercise training, named combined training (CT), by improving metabolic control may mitigate or reverse the cognitive impairment T2DM-related. Brain-derived neurotrophic factor (BDNF) plays a substantial role in cognitive functions. However, the effects of CT on BDNF levels of T2DM subjects are poorly known.Aim: This study analyzed the effects of 8 weeks of CT on circulating BDNF levels and assessed whether plasmatic BDNF levels were related to CT-induced improvements in executive functions and long-term memory of T2DM subjects.Methods: Thirty-five (63\u2009±\u20098 years old) T2DM subjects of both sexes entered into CT (n\u2009=\u200917, thrice-weekly during 8 weeks) or control group (CONT, n\u2009=\u200918). Executive functions (measured through Trail making test, Stroop color task, and Digit Span), long-term memory (measured through the simplified version of Taylor Complex Figure Test), and blood samples were evaluated pre- and post-intervention.Results: Pre-CT plasma BDNF levels were positively related to CT-induced improvements on executive functions composite z-score (r\u2009=\u20090.71), inhibitory control (r\u2009=\u20090.58) and cognitive flexibility (r\u2009=\u20090.56), but not to long-term memory. Plasma BDNF levels were not statistically changed (pre-CT: 179\u2009±\u200988 pg/ml; post-CT: 148\u2009±\u2009108 pg/ml; pre-CONT: 163\u2009±\u200971 pg/ml; post-CONT: 141\u2009±\u200984 pg/ml, p\u2009>\u20090.05).Conclusion: Higher pre-training BDNF levels might be a potentializing factor of the training-induced improvements on executive functions, independently of the training-alterations in resting BDNF levels of T2DM subjects.