The role of nitric oxide (NO) levels in patients with obstructive sleep apnea-hypopnea syndrome: a meta-analysis

Purpose The pathogenesis of cardiovascular disease (CVD) in patients with obstructive sleep apnea (OSA) is unclear. Several studies have suggested that CVD may be caused by oxidative stress from chronic intermittent hypoxia and associated vascular endothelial dysfunction. Oxidative stress in patients with OSA can induce endothelial cell apoptosis, aggravate vascular endothelial damage, and promote the expression of redox-sensitive genes and adhesion molecules. No meta-analysis has explored whether or not OSA is related to nitric oxide (NO). Method To assess the association between serum/plasma NO levels and OSA, we performed a meta-analysis of the literature on the subject to grade the strength of evidence. Results OSA was significantly related to decreased serum or plasma NO levels (WMD = − 11.66, 95% CI − 17.21 to − 6.11; P