A systematic review including 12 RCTs with a total of 572 subjects was abstracted in DARE. The pooled estimate of the effect of the continuous positive airway pressure (CPAP) intervention was a net decrease of 1.69 mm Hg in 24-hour ambulatory mean blood pressure (95% CI –2.69 to –0.69; random-effects model; moderate statistical heterogeneity, I2 = 41%). Predefined metaregression analyses estimated that 24-hour MBP would decrease by 0.89 mm Hg per 10-point increase in apnea-hypopnea index at entry (P = 0.006), by 0.74 mm Hg for each increase of 10 arousal events per hour slept (P = 0.008), and by 1.39 mm Hg for each 1-hour increase in effective nightly use of the CPAP device (P = 0.01).
Another systematic review including 16 RCTs (9 parallel-group, 7 crossover) with a total of 818 subjects was abstracted in DARE. CPAP was associated with a clinically significant reduction in the mean net change in systolic blood pressure (–2.46 mmHg, 95% CI –4.30 to –0.62), diastolic blood pressure (–1.83 mmHg, 95% CI –3.05 to –0.61) and mean arterial pressure (–2.22 mmHg, 95% CI –4.38 to –0.05) compared with control. There was no significant difference between daytime and night-time BP measurements.