We found significant association between eNOS rs1799983 polymorphism and the risk of hypertension under any genetic model (T vs G: OR 1.44, 95% CI 1.26–1.63; GT vs GG: OR 1.34, 95% CI 1.18–1.52; TT vs GG: OR 1.80, 95% CI 1.41–2.31; GT + TT vs GG: OR 1.42, 95% CI 1.25–1.63; TT vs GG + GT: OR 1.68, 95% CI 1.35–2.08; GT vs GG + TT: OR 1.24, 95% CI 1.11–1.40) (Fig. 2). This evidence concerns the gene NOS3 and hypertensive disorder.