Brain-Derived Neurotrophic Factor Profile in Ischemic Heart Disease; a Systematic Review and Meta-Analysis

Abstract Background Patients with ischemic heart disease (IHD) are at high risk of ischemic heart events, and novel biomarkers that reflect the severity of atherosclerotic disease and the fragility of coronary plaques are warranted. The Brain-Derived Neurotrophic Factor (BDNF) regulates endothelial and macrophage activation, suggesting a role in atherosclerotic plaque behavior. However, the precise involvement of BDNF in cardiovascular events is still unknown. This is the major goal of this study. Method We explored four databases for studies comparing BDNF levels in patients with IHD and controls. The Newcastle-Ottawa scale was used to evaluate the quality of included articles, and statistical analyses were conducted using R version 4.0.4. Results The final analysis comprised nine investigations covering 1,137 IHD patients and 724 controls. The preliminary result revealed statistically insignificant lower levels of BDNF in IHD compared with controls (SMD = -0.57, 95% CI [-1.18; 0.04], p-value = 0.068). After removing outliers, the following statistically significant results were obtained: SMD − 0.41 (95% CI [-0.78; -0.03], p-value = 0.03). In addition, subgroup analysis demonstrated no significant difference between serum and plasma levels ( p-value = 0.53). No predictor for the difference in BDNF levels was revealed using meta-regression. Conclusion To conclude, when outlier studies were excluded, serum and plasma BDNF concentrations were considerably lower in patients with IHD than in healthy controls. Further studies of higher quality are required to investigate the function and value of BDNF in IHD.