Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a meta-analysis.

OBJECTIVE: To systematically analyze the studies that have examined the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with resistant hypertension and obstructive sleep apnea (OSA). METHODS: Design - meta-analysis of observational studies and randomized controlled trials (RCTs) indexed in PubMed and Ovid (All Journals@Ovid). participants: individuals with resistant hypertension and OSA; interventions - CPAP treatment. RESULTS: A total of six studies met the inclusion criteria for preintervention to postintervention analyses. The pooled estimates of mean changes after CPAP treatment for the ambulatory (24-h) SBP and DBP from six studies were -7.21 mmHg [95% confidence interval (CI): -9.04 to -5.38; P < 0.001; I² 58%) and -4.99 mmHg (95% CI: -6.01 to -3.96; P < 0.001; I² 31%), respectively. The pooled estimate of the ambulatory SBP and DBP from the four RCTs showed a mean net change of -6.74 mmHg [95% CI: -9.98 to -3.49; P < 0.001; I² 61%] and -5.94 mmHg (95% CI: -9.40 to -2.47; P = 0.001; I² 76%), respectively, in favor of the CPAP group. CONCLUSION: The pooled estimate shows a favorable reduction of BP with CPAP treatment in patients with resistant hypertension and OSA. The effects sizes are larger than those previously reported in patients with OSA without resistant hypertension.