title: Meta-analysis of all-cause and cardiovascular mortality in obstructive sleep apnea with or without continuous positive airway pressure treatment.
abstract: OBJECTIVE
  The associations between obstructive sleep apnea (OSA) and all-cause and cardiovascular mortality are well established but are not entirely consistent. To accurately evaluate these associations as well as the therapeutic effects of continuous positive airway pressure (CPAP), we conducted a comprehensive meta-analysis of all eligible cohort studies.
  
  
  METHODS
  Electronic literature databases (i.e., PubMed and Embase) were searched for relevant studies published before January 2016 that evaluated the associations between OSA and all-cause or cardiovascular mortality. Random-effect models were used to calculate the pooled hazard ratio (HR) and corresponding 95 % confidence intervals (CIs) for categorical risk estimates. The therapeutic effects of CPAP treatment for all-cause and cardiovascular mortality in OSA were examined through the meta-analysis.
  
  
  RESULTS
  The 27 cohort studies included in the meta-analysis included 3,162,083 participants. Compared to the control group, the pooled HR of all-cause mortality was 1.19 (95 % CI, 0.86-1.65) for mild OSA, 1.28 (0.96-1.69) for moderate OSA, and 2.13 (1.68-2.68) for severe OSA. The pooled HR of cardiovascular mortality was 1.24 (0.53-2.55) for mild OSA, 2.05 (0.57-5.47) for moderate OSA, and 2.73 (1.94-3.85) for severe OSA. All-cause mortality (HR 0.66; 0.59-0.73) and cardiovascular mortality (HR 0.37; 0.16-0.54) were significantly lower in CPAP-treated than in untreated patients. There were no differences in cardiovascular mortality in CPAP-treated OSA patients vs. normal control subjects (HR 0.82; 0.52-1.29).
  
  
  CONCLUSIONS
  Greater attention should be paid to severe OSA, as it is an independent predictor for risk for all-cause and cardiovascular mortality. CPAP is an effective treatment that reduces risk of mortality.
authors: Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Yishan Road 600, Shanghai, 200233, China.|Otolaryngological Institute of Shanghai Jiao Tong University, Yishan Road 600, Shanghai, 200233, China.|Clinical Research Center, Shanghai Jiao Tong University School of Medicine, South Chongqing Road 225, Shanghai, 200020, China.
authors: Yiqun
authors: Y
authors: Fu
authors: Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Yishan Road 600, Shanghai, 200233, China.|Otolaryngological Institute of Shanghai Jiao Tong University, Yishan Road 600, Shanghai, 200233, China.|Clinical Research Center, Shanghai Jiao Tong University School of Medicine, South Chongqing Road 225, Shanghai, 200020, China.
authors: Yunyan
authors: Y
authors: Xia
authors: Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Yishan Road 600, Shanghai, 200233, China.|Otolaryngological Institute of Shanghai Jiao Tong University, Yishan Road 600, Shanghai, 200233, China.|Clinical Research Center, Shanghai Jiao Tong University School of Medicine, South Chongqing Road 225, Shanghai, 200020, China.
authors: Hongliang
authors: H
authors: Yi
authors: Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Yishan Road 600, Shanghai, 200233, China. sunnydayxu2010@sjtu.edu.cn.|Otolaryngological Institute of Shanghai Jiao Tong University, Yishan Road 600, Shanghai, 200233, China. sunnydayxu2010@sjtu.edu.cn.|Clinical Research Center, Shanghai Jiao Tong University School of Medicine, South Chongqing Road 225, Shanghai, 200020, China. sunnydayxu2010@sjtu.edu.cn.
authors: Huajun
authors: H
authors: Xu
authors: Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Yishan Road 600, Shanghai, 200233, China. guanjian0606@sina.com.|Otolaryngological Institute of Shanghai Jiao Tong University, Yishan Road 600, Shanghai, 200233, China. guanjian0606@sina.com.|Clinical Research Center, Shanghai Jiao Tong University School of Medicine, South Chongqing Road 225, Shanghai, 200020, China. guanjian0606@sina.com.
authors: Jian
authors: J
authors: Guan
authors: Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Yishan Road 600, Shanghai, 200233, China.|Otolaryngological Institute of Shanghai Jiao Tong University, Yishan Road 600, Shanghai, 200233, China.|Clinical Research Center, Shanghai Jiao Tong University School of Medicine, South Chongqing Road 225, Shanghai, 200020, China.
authors: Shankai
authors: S
authors: Yin
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000401:mortality* / Q000628:therapy*; D016019:Survival Analysis
keywords: All-cause mortality; Cardiovascular mortality; Meta-analysis; Obstructive sleep apnea