The association of brain-derived neurotrophic factor Val66Met polymorphism with stroke outcomes: a cross-sectional pilot study

Aim: This study investigated the effect of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism on post-stroke outcomes, including quality of life, physical fitness, cognitive function, depression, and overall disability. Methods: The difference between Met carriers and non-Met carriers was analyzed for the entire sample and in pair-matched analysis, using age, sex, time since stroke, and race. Results: We evaluated 89 stroke participants (mean age, 57 ± 10 years; 58% male; 54% White, and 49% Hispanic). Twelve participants (13%) had one copy of the BDNF Val66Met (Val/Met heterozygotes) and none had two copies (Met/Met homozygotes). Comparing Met (n = 12) and non-Met carriers (n = 77), no significant differences were observed in demographics or clinical characteristics, including motor or cognitive outcomes. In pair-matched analysis, a significant difference was observed for the Center for Epidemiological Studies Depression (CES-D) scale, where Met carriers had significantly greater CES-D scores than non-Met carriers (24 ± 16 vs. 9 ± 9, p = 0.011). Regardless of the chosen CES-D cut-off scores (≥ 16 vs. ≥ 20), more cases of depressive symptomatology were observed among those with the BDNF Val66Met polymorphism than those without it (p values < 0.05). Conclusions: The BDNF Val66Met polymorphism may be associated with post-stroke depression but not motor or cognitive recovery.