Sleep Apnea and Cardiovascular Disease

Obstructive sleep apnea (OSA) is associated with incident coronary and cerebral vascular disease. The mechanisms underlying this association are thought to include increased sympathetic nervous system activity, oxidative stress, and systemic inflammation, with these effects mediated in part by elevated blood pressure and impaired glucose metabolism. In observational studies, OSA treatment with positive airway pressure (PAP) is associated with a reduction in cardiovascular disease risk. The aim of this review is to evaluate evidence from recent clinical trials that tested the impact of OSA treatment on major cardiovascular disease outcomes.

Multicenter randomized trials have demonstrated a significant, albeit modest, reduction in blood pressure with OSA treatment. Treatment of OSA has generally not demonstrated improvement in type 2 diabetes mellitus, although limited evidence suggests that treatment may be effective in the prediabetic period. However, recent randomized trials of PAP treatment for OSA failed to demonstrate a reduction in incident or recurrent cardiovascular disease events. This may reflect the enrollment of a mostly non-sleepy study sample, as recent evidence suggests that sleepiness is a predictor of adverse cardiovascular outcomes from OSA. PAP treatment of OSA lowers blood pressure and may improve glucose metabolism; however, randomized clinical trials do not indicate a reduction in cardiovascular risk with treatment of minimally symptomatic OSA patients.