In patients with sleep apnea, CPAP therapy enhances endothelial function, decreases abnormally elevated levels of circulating apoptotic endothelial cells, reduces neutrophil and monocyte production of free radicals, attenuates C-reactive protein (CRP), increases vasodilator levels, and mediates a decrease in vasoconstrictor levels [16]. This evidence concerns the gene CRP and sleep apnea syndrome.