BDNF and coronary artery disorder: Lower BDNF levels were confirmed in ischemic heart disease in both subgroups (serum: SMD = −0.73, 95% CI: −1.84; 0.37, p-value = 0.192; plasma: SMD: −0.37, 95% CI: −0.67; −0.08, p-value = 0.013) [55].