Background: Obstructive sleep apnea (OSA) is a major cause of secondary hypertension. Moreover, a considerable proportion of patients with essential hypertension have OSA. OSA also appears to increase the risk for cardiovascular disease and all-cause mortality. Continuous positive airway pressure (CPAP) treatment substantially reduces daytime somnolence and improves quality of life in patients with OSA. However, the effects of CPAP treatment on blood pressure (BP) are questionable. The aim of the present review is to summarize the evidence regarding the association between OSA with hypertension and the effects of CPAP treatment on BP in patients with OSA. The severity of OSA directly correlates with the increase in BP. Moreover, patients with OSA are at increased risk for developing hypertension. However, CPAP treatment does not result in substantial reductions in BP in unselected patients with OSA with moderate adherence to this treatment. Nevertheless, these effects are more pronounced in patients with more severe hypertension, more severe OSA and more importantly, in those who adhere to CPAP treatment.
Conclusion: Therefore, it is essential to improve the adherence to CPAP treatment in order to optimally manage this important cause of hypertension.