We investigated the association between the three polymorphisms of the endothelial nitric oxide synthase (eNOS) gene (single-nucleotide polymorphism (SNP); rs2070744, rs1799983, variable number tandem repeat (VNTR) in intron 4) and scores on the Hamilton Rating Scale for Depression, plasma metabolites of NO (NO(x) ) or ankle brachial index in patients with MDD and healthy controls.
We found that genotype Met/Met of the Val66Met polymorphism of the brain-derived neurotrophic factor gene was positively associated with depressive disorder (P < 0.05), but we were not able to find any significant associations of both the depressive disorder and metabolic syndrome with the remaining polymorphisms studied (methylenetetrahydrofolate reductase 677CT, methylenetet rahydrofolate reductase 1298AC, endothelial nitric oxide synthase Glu298Asp, and tyrosine hydroxylase).