title: Effect of CPAP therapy on cardiovascular events and mortality in patients with obstructive sleep apnea: a meta-analysis.
abstract: OBJECTIVE
  Continuous positive airway pressure (CPAP) therapy may decrease the risk of mortality and cardiovascular events in patients with obstructive sleep apnea. However, these benefits are not completely clear.
  
  
  METHODS
  We undertook a meta-analysis of randomized clinical trials identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database.
  
  
  RESULTS
  Eighteen studies (4146 patients) were included. Overall, CPAP therapy did not significantly decrease the risk of cardiovascular events compared with the control group (odds ratio (OR), 0.84; 95 % confidence intervals (CI), 0.62-1.13; p = 0.25; I (2) = 0 %). CPAP was associated with a nonsignificant trend of lower rate of death and stroke (for death: OR, 0.85; 95 % CI, 0.35-2.06; p = 0.72; I (2) = 0.0 %; for stroke: OR, 0.56; 95 % CI, 0.18-1.73; p = 0.32; I (2) = 12.0 %), a significantly lower Epworth sleepiness score (ESS) (mean difference (MD), -1.78; 95 % CI, -2.31 to -1.24; p < 0.00001; I (2) = 76 %), and a significantly lower 24 h systolic and diastolic blood pressure (BP) (for 24 h systolic BP: MD, -2.03 mmHg; 95 % CI, -3.64 to -0.42; p = 0.01; I (2) = 0 %; for diastolic BP: MD, -1.79 mmHg; 95 % CI, -2.89 to -0.68; p = 0.001; I (2) = 0 %). Daytime systolic BP and body mass index were comparable between the CPAP and control groups. Subgroup analysis did not show any significant difference between short- and mediate-to-long-term follow-up groups with regard to cardiovascular events, death, and stroke.
  
  
  CONCLUSIONS
  CPAP therapy was associated with a trend of decreased risk of cardiovascular events. Furthermore, ESS and BP were significantly lower in the CPAP group. Larger randomized studies are needed to confirm these findings.
authors.affiliation: Department of Respiratory Medicine, Beijing Tsinghua Changgung Hospital, Medical Center, Tsinghua University, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Cardiology, Binzhou City Center Hospital, No. 208, Huimin South Road, Binzhou, Shandong, China. sunyu2312@sina.com.|Department of Cardiology, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian, China. sunyu2312@sina.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Neonatology, Shenzhen Bao'an District Songgang People's Hospital, Shenzhen, Guangdong, China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Xue
authors.affiliation: Department of Cardiology, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian, China.
authors.forename: Zi-Yang
authors.initials: ZY
authors.lastname: Huang
authors.affiliation: Department of Cardiology, Binzhou City Center Hospital, No. 208, Huimin South Road, Binzhou, Shandong, China.
authors.forename: Yong-Shen
authors.initials: YS
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Binzhou City Center Hospital, No. 208, Huimin South Road, Binzhou, Shandong, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, Binzhou City Center Hospital, No. 208, Huimin South Road, Binzhou, Shandong, China.
authors.forename: Gui-Hua
authors.initials: GH
authors.lastname: Zhou
authors.affiliation: Department of Cardiology, Binzhou City Center Hospital, No. 208, Huimin South Road, Binzhou, Shandong, China.
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Yuan
mesh_terms: D001794:Blood Pressure; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000150:complications* / Q000401:mortality / Q000628:therapy*; D002423:Cause of Death; D015897:Comorbidity; D045422:Continuous Positive Airway Pressure; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000401:mortality / Q000628:therapy*
keywords: Cardiovascular events; Continuous positive airway pressure; Meta-analysis; Mortality; Obstructive sleep apnea; Sleepiness