Brain-derived neurotrophic factor correlated with muscle strength in subjects undergoing stationary bicycle exercise training.

Aims: Several central nervous disorders are associated with metabolic syndrome (MetS) and type 2 diabetes. Reduction in brain-derived neurotrophic factor (BDNF) is involved in the mechanism of central nervous dysfunction. BDNF is up-regulated after exercise, but it is not known whether increased BDNF is related to increases in muscle strength. Methods: In the present study, subjects with MetS or type 2 diabetes were enrolled in an exercise program. All participants underwent an indoor bicycle exercise program for twelve weeks. Serum BDNF was determined after overnight fasting. Muscle strength was assessed by extension of the dominant lower extremity. Results: A total of 33 subjects were enrolled in this study. The body mass index did not change significantly (from 30.4 ± 6.0 to 30.2 ± 5.8 kg/m², P = 0.436), but serum BDNF increased significantly (from 17.1 ± 9.1 to 24.2 ± 10.7 ng/mL, P < 0.001) after the study. The exercise-associated BDNF was significantly correlated with the increased strength in lower-extremity extension test (r = 0.54, P = 0.001). Using multivariate regression analysis, muscle-strength increment, but not body-weight change, was an independent factor for serum BDNF (95% CI = 0.009-0.044, P = 0.005). Conclusions: After a twelve-week program of stationary bicycle exercise, serum BDNF concentration increased, and this change was positively correlated with muscle strength of lower-extremity extension, but not body weight. [ABSTRACT FROM AUTHOR]