Low Serum Levels of Brain-Derived Neurotrophic Factor Were Associated with Poor Short-Term Functional Outcome and Mortality in Acute Ischemic Stroke

Circulating brain-derived neurotrophic factor (BDNF) has been highlighted as being a key regulator of rehabilitation-induced recovery after stroke. The aim of this study was to evaluate the association between serum levels of BDNF and functional outcome and mortality events in a 3-month follow-up study in a cohort of patients with an acute ischemic stroke (AIS). From January 2015 to December 2015, consecutive first-ever AIS patients admitted to the Department of Emergency of our hospital were identified. Serum BDNF levels were measured at admission. Functional outcome was evaluated at 3 months using the modified Rankin scale (m-Rankin). We used logistic regression models to assess the relationship between BDNF levels and functional outcome or mortality. In this study, 204 patients were included. Patients with poor outcomes and non-survivors had significantly lower BDNF levels on admission (P < 0.0001 all). Multivariate logistic regression analysis adjusted for common risk factors showed that BDNF levels in the lowest interquartile (≤1st 9.2 ng/ml) was an independent predictor of functional outcome (odds ratios [OR] = 3.75; 95 % confidence interval [CI], 2.43–8.12) and mortality (OR = 4.04; 95 % CI, 2.07–9.14). The area under the receiver operating characteristic curve of BDNF was 0.77 (95 % CI, 0.70–0.84) for functional outcome and 0.79 (95 % CI, 0.71–0.86) for mortality. The findings indicated that low serum levels of BDNF at admission were significantly associated with poor short-term functional outcome and mortality, suggesting that BDNF may serve as a biomarker of poor function outcome after stroke.