Table 3: Characteristics of study subjects.
| Eweda et. al, 2015 | Sabit et. al, 2010 | Yilmaz et al, 2005 | Wahsh et al, 2013 | Funk et al, 2008 | Suchon et al, 2007 | Abo-El Magd et al, 2017 | Acharya et al, 2018 |
| Control total | 20 | 14 | 24 | 12 | 22 | 25 | 20 | 50 |
| COPD total | 40 | 36 | 44 | 36 | 22 | 35 | 60 | 50 |
| Control average age | 51.40+/-3.89 | 67+/-8.8 | 63+/-12 | 51.9+/-9.7 | 54.8+/-1.3 | 61.6+/-10.1 | 57.42+/-6.44 | * |
| COPD average age | 51+/-5 | 66.5+/-8.9 | 64.4+/-8 | 55.1+/-7.3 | 59.1+/-1.7 | 62.1+/-7.7 | 57.73+/-5.93 | * |
| Control male n (%) | 10 | 9 | 13(65) | 6(50) | n/a | 18 (72) | 12 | * |
| COPD male n (%) | 19 | 19 | 31 | 30(83.3) | n/a | 25(71) | 42 | * |
| Control average BMI | n/a | 26.9+/-3.2 | n/a | n/a | n/a | n/a | n/a | * |
| COPD average BMI | n/a | 27.3+/-4.9 | n/a | n/a | n/a | n/a | n/a | * |
| Control HTN n (%) | 0 | n/a | 0 | n/a | 0 | 0 | n/a | 0 |
| COPD HTN n (%) | 0 | n/a | 0 | n/a | 0 | 0 | n/a | 0 |
| Control DM n (%) | 0 | n/a | n/a | n/a | 0 | n/a | 0 | 0 |
| COPD DM n (%) | 3 | n/a | n/a | n/a | 0 | n/a | 0 | 0 |
| Control CVD n (%) | 0 | n/a | 0 | 0 | 0 | 0 | 0 | 0 |
| COPD CVD n (%) | 0 | n/a | 0 | 0 | 0 | 0 | 0 | 0 |
| Control CKD n (%) | 0 | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| COPD CKD n (%) | 0 | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| * Author did not provide continuous demographic information |
| Kubota et al, 2016 | Boussuges et al, 2000 | Farouk et al, 2017 | Malerba et al, 2011 | Huang et al, 2014 | Faludi et al, 2016 | Pela et al, 2016 | |
| Control total | 115 | 20 | 18 | 40 | 73 | 34 | 36 | |
| COPD total | 115 | 34 | 35 | 55 | 75 | 65 | 49 | |
| Control average age | 74.4 | 60+/- 10 | 56+/-8 | 55.9 +/- 11.4 | 78.67±7.14 | 58+/-8.3 | 62.7 | |
| COPD average age | 74.4 | 58+/-11 | 58.9+/-9 | 58.8 +/- 11.5 | 82.76±5.71 | 60.8+/-9 | 66.3 | |
| Control male n (%) | 72.3 (65) | 12(60) | 100 | 21 (52) | 51 (69.9) | 18 (53) | 24 (69) | |
| COPD male n (%) | 72.3(65) | 21(61.7) | 100 | 23 (52) | 60 (80.0) | 39 (60) | 37 (76) | |
| Control average BMI | 21.5 | wt. 65 +/-17 | 26+/-5 | 27.7 +/- 4.4 | 23.92±3.10 | n/a | 25.8 | |
| COPD average BMI | 22.5 | wt. 76 +/-15 | 25.6 | 28.4 +/- 4.2 | 23.56±3.10 | n/a | 25.3 | |
| Control HTN | n (%) | 64 (55.4) | 0 | 0 | 0 | 41 (56.2) | n/a | |
| COPD HTN n (%) | 53 (45.5) | 0 | 0 | 0 | 52 (69.3) | 51 (78) | 0 | |
| Control DM n (%) | 20.5 | 0 | 0 | 0 | 27 (36.9) | n/a | 0 | |
| COPD DM n (%) | 25 | 0 | 0 | 0 | 17 (45.4) | 18 (28) | 3 | |
| Control CVD n (%) | 0 | 0 | 0 | 0 | 32 (43.8) | 0 | 0 | |
| COPD CVD n (%) | 0 | 0 | 0 | 0 | 29 (38.7) | 9 (12) | 0 | |
| Control CKD n (%) | 38.4 | 0 | 0 | n/a | 12 (16.4) | n/a | n/a | |
| COPD CKD n (%) | 41.4 | 0 | 0 | n/a | 14 (18.7) | n/a | n/a | |