In rats with the metabolic syndrome, induced by chronic consumption of a high fat, high refined sugar [31], hypertension is associated with oxidative stress [32], avid nitric oxide (NO) inactivation, and down-regulation of NO synthase (NOS) isoforms and endothelial NOS activator [32], suggesting that oxidative stress and endothelial dysfunction may be strongly associated with development of hypertension in the metabolic syndrome. This evidence concerns the gene NOS3 and hypertensive disorder.