Role of rs6265 BDNF polymorphisms and post‐stroke dysphagia recovery—A prospective cohort study

Background Previous studies suggest that specific genes may predispose some to increased risk of dysphagia in the geriatric population, but whether these genes may affect swallowing recovery after a stroke is unknown. This study investigated whether single‐nucleotide polymorphisms (SNP) of the brain‐derived neurotrophic factor (BDNF), catechol‐O‐methyl transferase, apolipoprotein E, interleukin‐1 receptor antagonist, and dopamine, which have been linked to swallowing, could adversely affect the prognosis of post‐stroke dysphagia. Methods In this study, 218 subjects with confirmed post‐stroke dysphagia were enrolled. The primary endpoint was failed recovery from nil per mouth (NPM) status with the first 3 months post‐stroke. Key Results The Val/Val group from the rs6265, BDNF, showed higher score changes on the Functional Oral Intake Scale at 1 month. The proportion of patients with recovery from NPM status within the first 1 month was 60.8% in the Val/Val group, which was statistically higher than those in the Met allele groups (38.1%, P = .017). At 3 months, the BDNF rs6265 showed significant group differences in Modified Barium Swallow Impairment Profile© score changes with the Val/Val allele leading to greater improvement. However, no single SNP was associated with increased risk of poor recovery with persistence of NPM at 3 months post‐stroke. Conclusions and Inferences Those with the dominant Val/Val phenotype of BDNF manifested with faster and greater improvement than the Met‐phenotypes. Based on our results, the BDNF Val allele may play a positive role with faster score improvement and rapid recovery from NPM than the Met allele. Clinical Trials gov: NCT03577444 (https://clinicaltrials.gov/ct2/show/study/NCT03577444). BDNF rs6265 Val/Val manifested with more significant improvement in swallowing than the Met‐alleles within the first few months post‐stroke. These changes were observed with shorter nil per mouth duration, and greater changes in the Functional Oral Intake Scale and MBSImP© scores.