Continuous positive airway pressure reduces blood pressure in patients with obstructive sleep apnea; a systematic review and meta-analysis with 1000 patients

Background: Obstructive sleep apnea (OSA) may lead tothe development of hypertension and therapy withcontinuous positive airway pressure (CPAP) can promotereduction in blood pressure.Objective: The objective of this study is to reviewsystematically the effects of CPAP on blood pressure inpatients with OSA.Methods: The search was conducted in the followingdatabases, from their beginning until February 2013:MEDLINE, Embase, Cochrane CENTRAL, Lilacs and PEDro.In addition, a manual search was performed on referencesof published studies. Randomized clinical trials (RCTs) thatused CPAP compared with placebo CPAP orsubtherapeutic CPAP for treatment of patients with OSAand that evaluated office systolic blood pressure (SBP) anddiastolic blood pressure (DBP) and 24-h ambulatory bloodpressure were selected.Results: Sixteen RCTs were included among 3409publications, totaling 1166 patients. The use of CPAP resultedin reductions in office SBP [ 3.20mmHg; 95% confidenceinterval (CI) 4.67 to 1.72] and DBP ( 2.87mmHg; 95% CI 5.18 to 0.55); in night-time SBP ( 4.92mmHg; 95% CI 8.70 to 1.14); in mean 24-h blood pressure( 3.56mmHg; 95% CI 6.79 to 0.33), mean night-timeblood pressure ( 2.56mmHg; 95% CI 4.43 to 0.68) and24-h DBP ( 3.46mmHg; 95% CI 6.75 to 0.17). However,no significant change was observed in daytime SBP( 0.74mmHg; 95% CI 3.90 to 2.41) and daytime DBP( 1.86mmHg; 95% CI 4.55 to 0.83).Conclusion: Treatment with CPAP promoted significantlybut small reductions in blood pressure in individuals withOSA. Further studies should be performed to evaluate theeffects of long-term CPAP and the impact oncardiovascular risk.Keywords: arterial pressure, continuous positive airwaypressure, hypertension, sleep apnea, obstructive sleepapnea syndromesAbbreviations: 95%CI, 95% confidence interval; AHI,apnea–hypopnoea index; CPAP, continuous positive airwaypressure; DBP, diastolic blood pressure; OSA, obstructivesleep apnea; RCTs, randomized clinical trials; SBP, systolicblood pressure