The Role Of Continuous Positive Airway Pressure In Blood Pressure Control For Patients With Obstructive Sleep Apnea And Hypertension:a Meta-Analysis Of Randomized Controlled Trials

Background:Continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea syndrome (OSAS) and hypertension might decrease blood pressure (BP), but evidences from clinical trials have not been consistent.Objective:The aim of this study was to quantitatively review the effect of CPAP therapy on BP in the patients with OSAS and hypertension.Methods:Major electronic information sources were explored for randomized controlled trials (RCTs) comparing CPAP with control among patients with OSAS and hypertension. The primary outcome was the net change of 24-hour ambulatory BP. The secondary outcomes were consisted of the net changes of nocturnal and diurnal ambulatory BP.Results:Seven RCTs reporting 24-hour ambulatory BP were identified for meta-analysis. CPAP was associated with significant reductions in 24-hour ambulatory systolic blood pressure (SBP) (-2.32 mmHg; 95%confidence interval [CI],-3.65 to-1.00, p=0.001) and diastolic blood pressure (DBP) (-1.98mmHg; 95%CI:-2.82 to-1.14, p<0.001); in nocturnal SBP (-2.74mmHg; 95%CI:-4.26 to-1.23, p<0.001) and nocturnal DBP (-1.75mmHg; 95%CI:-2.79 to-0.71, p=0.001); and in diurnal DBP (-2.85mmHg; 95%CI:-5.58 to-0.12, p=0.041). However, no significant change was observed in diurnal SBP (-3.58mmHg; 95%CI:-8.04 to 0.89, p=0.117). Meta-regression indicated that CPAP compliance, age, and baseline SBP were positively correlated with decrease in 24-hour DBP, but not reduction in 24-hour SBP.Conclusions:CPAP significantly reduces 24-hour ambulatory BP in the patients with OSAS and hypertension, which led to more significant improvement in nocturnal SBP than that in diurnal SBP. Subgroup analysis showed that patients with resistant hypertension or receiving antihypertensive drugs benefited most from CPAP.