Cross-sectional Analysis on the Association of Brain-derived Neurotropic Factor Vall66Met Polymorphism with Stroke Outcomes

Background and/or Objectives: To investigate the effect of BDNF Vall66Met polymorphism on post stroke outcomes including depression, quality of life, physical fitness, cognitive function, and overall disability.

Design: Cross-sectional exploratory study as part of a larger cohort study

Setting: University health system, a large academic health system in an urban setting

Participants: We evaluated 89 stroke participants (mean age, 57±10 years; 58% male; 54% White, and 49% Hispanic) with available data on the polymorphism and stroke outcomes. The difference between Met-carriers and non-Met carriers were analyzed for the entire sample and in pair-matched analysis, using gender, sex, time since stroke, and race.

Interventions: not applicable

Main Outcome Measures: Stroke-specific quality of life, physical fitness, cognition function, and depression

Results: Twelve participants (13%) had one copy of the BDNF Vall66Met (Val/Met heterozygotes) and none had two copies (Met/Met homozygotes). Comparing Met (n=12) and non-Met carriers (n=77) no statistically significant differences were observed in demographics or clinical characteristics, including motor or cognitive outcomes. In pair-matched analysis, the significant difference was observed for Center of 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 Vall66Met polymorphism than those without it (p values = ≤0.05).

Conclusions: The BDNF Vall66Met polymorphism is associated with depressive symptomatology but not physical recovery and cognitive outcomes post-stroke. Future studies should continue to explore the role of the BDNF Vall66Met polymorphism in stroke recovery.