Significance of low plasma levels of brain-derived neurotrophic factor in patients with heart failure.

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, which regulates neuronal differentiation and functions. Low levels of BDNF are because of psychological stress and potentially play a role in the pathogenesis of depression and cognition disorders. Because psychological stress and depression are associated with increased risk of heart failure (HF), the pathogenic link between HF and psychological status has attracted clinical attention. We hypothesized that plasma BDNF levels might be decreased in patients with HF and that BDNF could be a key factor associated with HF. We evaluated plasma BDNF levels in 242 patients with HF and 80 subjects without HF who are age and gender matched. Plasma BDNF levels were significantly lower in patients with HF (3,712 pg/ml [2,124 to 6,180]) than those without HF (7,247 pg/ml [5,388 to 9,255], p <0.001) and lower in patients with HF with the New York Heart Association functional class III than class I (p = 0.01) and class II (p <0.001). Log BDNF levels correlated negatively with log B-type natriuretic peptide (r = -0.203, p = 0.03) in patients with HF. Of 61 acute decompensated patients with HF, plasma BDNF levels were significantly higher at discharge (4,194 pg/ml [2,356 to 6,916]) compared with those at admission (2,749 pg/ml [1,380 to 4,161], p = 0.003). Multivariate logistic regression analysis identified log BDNF level as a significant correlate with the presence of HF (odds ratio 0.82; 95% confidence interval 0.76 to 0.91, p <0.001). In conclusion, plasma BDNF levels were decreased in patients with HF and associated with HF severity. BDNF could be a potentially clinically useful biomarker of HF reflecting possible cardio-neuronal linkage.