Table 1.
Characteristics of included studies.
| Study | Study Design | Diagnosis Criteria of OS | Population | Adjustment | Outcome | Quality* |
|---|---|---|---|---|---|---|
| Bai, 201714 | Case-control study | COPD: criteria established by the Chinese Medical Association (2011) | COPD: 27, OSA: 21 | Sex | Hypertension | 6 |
| OSA: criteria established by the Chinese Medical Association (2013) (PSG) | OS: 22 | |||||
| Chaouat et al, 199515 | Cross-sectional study | COPD: FEV1/FVC ratio ≤ 60% | OSA: 194 | No | PH | 7 |
| OSA: AHI > 20 (PSG) | OS: 26 | |||||
| Du et al, 201816 | Cross-sectional study | COPD: answered yes to the question “Has a doctor or other health professional ever told you that you had chronic bronchitis or emphysema?” | COPD: 695, OSA: 366 | No | Hypertension | 8 |
| OSA: answered yes to the question “Have you ever been told by a doctor or other health professional that you have a sleep disorder?” and reported sleep apnea to “What was the sleep disorder?” | OS:90 | |||||
| Steveling et al, 20144 | Cross-sectional study | COPD: GOLD (2013) | COPD: 144 | Age | Hypertension | 8 |
| OSA: AHI > 10 events/h (Apnealink) | OS: 33 | Smoking | ||||
| Greenberg-Dotan et al, 20131 | Case-control study | COPD: International Classification of Diseases, Ninth Revision | COPD: 41 | Age, sex | Hypertension | 8 |
| OSA: AHI ≥ 5 events/h (PSG) | OS: 57 | Smoking | PH | |||
| Gunduz et al, 201817 | Cross-sectional study | COPD: GOLD (2014) | COPD:19 | Age, sex | PH | 7 |
| OSA: RDI ≥ 15(Watch-PAT) | OS: 26 | Smoking | ||||
| Han et al, 201318 | Cross-sectional study | COPD: GOLD (2008) | COPD: 36, OSA: 96 | Age, sex | Hypertension | 6 |
| OSA: criteria established by the Chinese Medical Association (2011) (PSG) | OS: 32 | |||||
| Hang et al, 201611 | Cross-sectional study | COPD: 5 questions about COPD and respiratory symptoms to identify diagnosed COPD or related respiratory symptoms of 3 months duration | COPD: 206 | Age, sex | Stroke | 8 |
| OSA: Berlin Questionnaire | OS: 86 | Smoking | ||||
| Hawrylkiewicz et al, 200419 | Cross-sectional study | COPD: Optimal assessment and management of chronic obstructive pulmonary disease (COPD) (1995) | OSA: 67 | No | PH | 6 |
| OSA: ATS recommendations (PSG) | OS: 17 | |||||
| Lacedonia et al, 201820 | Cross-sectional study | COPD: postbronchodilator FEV1/FVC ratio of < .7 | OSA: 721 | No | Hypertension | 6 |
| OSA: AASM criteria (cardio-respiratory overnight monitoring) | OS: 123 | |||||
| Taranto- Montemurro et al, 201621 | Cross-sectional study | COPD: GOLD (2013) | COPD: 16, OSA: 24 | No | Hypertension | 7 |
| OSA: AASM (2012) (cardio-respiratory polysomnography) | OS: 14 | |||||
| Niu et al, 201022 | Cross-sectional study | COPD: criteria established by the Chinese Medical Association (2007) | COPD: 53, OSA: 50 | Not mentioned | PH | 6 |
| OSA: criteria established by the Chinese Medical Association (2002) (PSG) | OS: 25 | |||||
| Ou et al, 201823 | Cross-sectional study | COPD: GOLD (2011) | COPD: 55 | BMI | PH | 6 |
| OSA: criteria established by the Chinese Medical Association (2011) (PSG) | OS: 32 | |||||
| Silva Junior et al, 201824 | Cross-sectional study | COPD: postbronchodilator FEV1/FVC ratio < 70 | COPD: 25 | Age, sex | Hypertension | 8 |
| OSA: AHI ≥ 15 events/h (PSG) | OS: 14 | Smoking,BMI | PH | |||
| Sun, 201525 | Cross-sectional study | COPD: criteria established by the Chinese Medical Association (2011) | COPD: 54 | Age, sex | Hypertension | 8 |
| OSA: AHI ≥ 5 events/h (Apnealink) | OS: 28 | Smoking | CHD, PH | |||
| Sun et al, 201926 | Cross-sectional study | COPD: GOLD (2017) | COPD: 50 | Age, sex | Hypertension | 9 |
| OSA: AHI ≥ 10 events/h (Apnealink) | OS: 56 | Smoking,BMI | CHD, PH, CVD | |||
| Xie et al, 201927 | Cross-sectional study | COPD: GOLD (2007) | COPD: 62, OSA: 735 | No | Hypertension | 8 |
| OSA: AHI ≥ 15 events/h (PSG) | OS: 49 | CHD, CVD |
*
The cross-sectional study was measured by the Agency for Healthcare Research and Quality; the case-control study was evaluated by the Newcastle-Ottawa Scale. AASM = American Academy of Sleep Medicine, AHI = apnea-hypopnea index, BMI = body mass index, CHD = coronary heart disease, COPD = chronic obstructive pulmonary disease, CVD = cerebrovascular disease, GOLD = global initiative for obstructive lung disease, OS = overlap syndrome, OSA = obstructive sleep apnea, PH = pulmonary hypertension, PSG = polysomnography, RDI = respiratory disturbance index.