Objective Studies suggest that continuous positive airway pressure (CPAP) therapy may decrease blood pressure for patients with obstructive sleep apnoea (OSA). However, these benefits are not completely clear.

Method We undertook a meta-analysis of randomized trials identified in systematic researches of MEDLINE, EMBASE, and the Cochrane Database.

Results Twelve studies (1,720 patients) were included. Overall, CPAP therapy significantly decreased 24-h systolic blood pressure (SBP) (MD, -2.03; 95% CI, -3.64 to -0.42; P= 0.01; I2 = 0%) and 24-h diastolic blood pressure (DBP) (MD, -1.79; 95% CI, -2.89 to -0.68; P= 0.001; I2 = 0%) compared with the control group. Meanwhile, CPAP was associated with significantly lower daytime DBP (MD, -1.43; 95% CI, -2.67 to -0.19; P= 0.02; I2 = 0%), nighttime SBP (MD, -3.94; 95% CI, -5.85 to -2.04; P < 0.0001; I2 = 34%), nighttime DBP (MD, -1.64; 95% CI, -2.88 to -0.40; P= 0.009; I2 = 0%), clinic SBP (MD, -4.53; 95% CI, -6.07 to -2.99; P < 0.00001; I2 = 70%) and clinic DBP (MD, -2.94; 95% CI, -4.16 to -1.72; P < 0.00001; I2 = 56%). Furthermore, the risk of cardiovascular events was significantly decreased in the CPAP group (OR, 0.59; 95% CI, 0.36 to 0.98; P= 0.04; I2 = 0%).

Conclusions CPAP therapy was associated with a significantly decreased level of BP and cardiovascular events. However, larger randomized studies are needed to confirm these findings.