The relationship between brain-derived neurotrophic factor, irisin and cognitive skills of endurance athletes.

Abstract

The objective of this study was to assess the cognitive performance of endurance athletes and its relation with circulating brain-derived neurotrophic factor (BDNF) and irisin levels. 26 endurance athletes (14 elite orienteers (mean ± SD: age = 26.33 ± 4.08, body weight = 70.33 ± 4.64, body height = 177.7 ± 6.1), 12 pentathletes (mean ± SD: age = 29.42 ± 5.32, body weight = 74.77 ± 6.59, body height = 180.8 ± 3.8)) and ten sedentary (mean ± SD: age = 27.30 ± 2.06, body weight = 76.65 ± 12.50, body height = 176.9 ± 5.2) men at almost same ages and educational levels participated in this study. Cognitive functions were analyzed with mini-mental-state examination (MMSE) and Isaacs' Set Test of Verbal Fluency (IST) tests. Insulin-like growth factor-1 (IGF-1), BDNF and irisin levels were measured in the blood samples. The MSSE and IST scores of the endurance athletes were higher than that of the sedentary control group (P < 0.05). Serum IGF-1 levels were higher in the pentathletes (111.18 ± 22.26 ng mL(-1)) than the orienteers (85.89 ± 19.32 ng mL(-1)) (P < 0.05). Plasma BDNF (2.78 ± 0.81, 4.28 ± 1.03, and 3.93 ± 0.77 ng mL(-1) in the sedentary, orienteers and pentathletes, respectively) and irisin (3.25 ± 0.70, 6.16 ± 0.99, and 6.58 ± 1.09 µg mL(-1) in the sedentary, orienteers and pentathletes, respectively) concentrations of the endurance trained athletes were higher than that of the sedentary control group (P < 0.05). Positive correlation between the cognitive function test results and BDNF and irisin concentrations were observed (P < 0.05). There was also a positive correlation between the circulating irisin and BDNF concentrations (P < 0.05). These results suggested that irisin and BDNF levels positively correlated with cognition in the endurance trained athletes.