Table 3.
Clinical characteristics across the (co)morbidity clusters in COPD.
| C1 | C2 | C3 | C4 | C5 | |
|---|---|---|---|---|---|
| Cluster description | Less Comorbidity | Cardiovascular | Metabolic | Psychologic | Cachectic |
| Subjects, n (%) | 46 (22%) | 27 (13%) | 56 (27%) | 40 (19%) | 39 (19%) |
| Male, % | 63 | 67 | 64 | 43 1 | 51 |
| Age, years | 61 ± 7 | 65 ± 7 1 | 64 ± 6 | 61 ± 8 | 60 ± 6 |
| BMI, kg/m2 | 27.2 ± 4.0 | 26.9 ± 3.5 | 31.1 ± 4.9 1 | 27.5 ± 3.8 | 19.9 ± 2.0 1 |
| Waist circumference, cm | 102 ± 12 | 102 ± 12 1 | 112 ± 14 | 102 ± 15 | 82 ± 8 1 |
| Former smoker, % | 59 | 89 1 | 75 | 58 | 49 1 |
| Current smoker, % | 39 | 11 1 | 26 | 40 | 49 1 |
| Pack-years, n | 39 (27–45) 1 | 40 (27–45) | 45 (32–57) | 58 (31–84) 1 | 43 (28–59) |
| Fram.10yr. risk ≥ 30%, % | 18 1 | 37 | 60 1 | 26 | 10 1 |
| FEV1, % predicted | 51 ± 16 | 49 ± 16 | 56 ± 13 1 | 48 ± 15 | 40 ± 15 1 |
| FEV1/FVC | 41 ± 12 | 40 ± 10 | 46 ± 11 1 | 40 ± 11 | 36 ± 12 1 |
| ITGV, % predicted | 139 ± 28 | 149 ± 30 | 128 ± 30 1 | 144 ± 30 | 171 ± 32 1 |
| KCO, % predicted | 67 ± 22 | 68 ± 17 | 80 ± 24 1 | 66 ± 18 | 58 ± 18 1 |
| MRC dyspnea grade | 3.0 ± 0.8 | 2.9 ± 1.1 | 2.9 ± 1.2 | 3.2 ± 0.9 | 3.0 ± 1.1 |
| SGRQ, total score | 48.3 ± 15.0 1 | 56.1 ± 18.7 | 53.6 ± 15.1 | 66.2 ± 13.7 1 | 52.2 ± 16.2 |
| 6MWD, m | 445 ± 168 | 450 ± 159 | 462 ± 121 | 466 ± 100 | 465 ± 116 |
| ≥2 ex. previous year, % | 46 | 33 | 44 | 48 | 53 |
Abbreviations: BMI = body mass index; Fram.10-yr. risk = Framingham 10-year risk of overall cardiovascular disease; FEV1 = Forced expiratory volume in 1 s; FVC = Forced vital capacity. ITGV = Intrathoracic gas volume. KCO = Transfer factor for carbon monoxide per alveolar volume. MRC = Medical Research Council. SGRQ = St. George’s Respiratory Questionnaire. 6MWD = 6-min walking distance. ex. = Exacerbations. kbp = Kilobase pairs. NA = Not applicable. Summary variables are presented as mean ± standard deviation for quantitative variables, with exception of pack-years (median and interquartile range), and percentage for discrete variables. 1 p < 0.05 versus COPD group.