Table 1. General characteristics of included studies.
| Author, year* | Study period | Country | Outcomes | Characteristics of OSAS patients | Quality assessment |
|---|---|---|---|---|---|
| OSAS subjects with/without CVD | |||||
| Sunnetcioglu, 2018 | 201301–201510 | Turkey | HGB, RDW | OSAS w/wo diabetes, hypertension, smoking and CVD | Strong |
| Song, 2016 | 201001–201412 | Korea | WBC, NEU, LYM, RBC, HGB, HCT, RDW, PLT, PLR, PDW | OSAS w/wo diabetes, smoking, primary hypertension, and hyperlipidemia | Strong |
| Uygur, 2016 | 201209–201403 | Turkey | WBC, NEU, LYM, NLR, HGB, RDW, PLT, PDW, MPV | OSAS w/wo diabetes, hypertension, CVD and hyperlipidemia | Strong |
| Koseoglu, 2015 | NA | Turkey | PLT, LYM, PLR, MPV, PDW, RDW | OSAS w/wo diabetes, hypertension, CVD and smoking | Strong |
| Sokucu, 2014 | 201201–201207 | Turkey | WBC, RBC, HGB, HCT, PLT, MPV, PDW | OSAS w/wo smoking and hypertension but wo CVD and diabetes | Strong |
| Kanbay, 2013 | 200501–201010 | Turkey | MPV, HGB, WBC, PLT | OSAS w/wo CVD | Strong |
| Kurt, 2013 | 201103–201207 | Turkey | WBC, RDW, HGB, MPV, PDW, PLT | OSAS w/wo diabetes, hypertension, CVD, hyperlipidemia and smoking | Strong |
| Ozsu, 2012 | NA | Turkey | HGB | OSAS w/wo diabetes, hypertension, CVD and smoking | Strong |
| Varol, 2011 | 200809–200909 | Turkey | HGB, WBC, PLT, MPV | OSAS w/wo diabetes, hypertension and smoking | Strong |
| Varol, 2010 | NA | Turkey | HGB, WBC, PLT, MPV | OSAS w/wo diabetes, hypertension and smoking | Strong |
| OSAS subjects without CVD | |||||
| Altintas, 2015 | 201301–201404 | Turkey | NLR | OSAS wo diabetes, hypertension, CVD and smoking | Strong |
| Korkmaz, 2015 | 201211–201312 | Turkey | WBC, NEU, LYM, NLR, LYM | OSAS wo diabetes, hypertension, CVD and hyperlipidemia | Strong |
| Koseoglu, 2015 | 201005–201307 | Turkey | PLR, NLR | OSAS wo CVD | Strong |
| Yenigun, 2015 | NA | Turkey | NLR, NEU, LYM, WBC | OSAS wo CVD. | Strong |
| Karakas, 2013 | 200903–201010 | Turkey | HGB, PLT, MPV | OSAS wo diabetes, hypertension, CVD, hyperlipidemia and smoking | Strong |
| Nena, 2012 | NA | Greece | MPV, PDW | OSAS wo diabetes and smoking | Strong |
| Choi, 2006 | NA | California | HGB, HCT, WBC | OSAS wo diabetes, hypertension, CVD and smoking | Strong |
*, all studies were retrospective case series. WBC, white blood cell; LYM, lymphocyte; NEU, neutrophil; NLR, neutrophil-to-lymphocyte ratio; RBC, red blood cell; PLT, platelet; PLR, platelet-to-lymphocyte ratio; HGB, hemoglobin; HCT, hematocrit; RDW, red cell distribution width; MPV, mean platelet volume; PDW, platelet distribution width; CVD, cardiovascular disease; COPD, chronic obstructive pulmonary disease; w/o, without; w/wo, with and without.