| Low weight | Normal weight | Overweight | Obesity | |
| BMI ⩽21 (n = 222) | BMI 21.01–24.99 (n = 583) | BMI 25–29.99 (n = 690) | BMI ⩾30 (n = 266) | |
| Age* | 60.3 (11.2) | 62.2 (10.7) | 63.9 (10.3) | 63.6 (10.0) |
| Gender (male) | 104 (46.8) | 363 (62.3) | 497 (72.0) | 168 (63.2) |
| Current smoker | 154 (69.4) | 331 (56.8) | 289 (41.9) | 111 (41.7) |
| GOLD stages | ||||
| I | 32 (14.4) | 89 (15.3) | 91 (13.2) | 22 (13.3) |
| II | 100 (45.0) | 362 (62.1) | 440 (63.8) | 187 (70.3) |
| III or IV | 90 (40.6) | 132 (22.6) | 159 (23.1) | 57 (21.5) |
| MRC score | ||||
| 0 | 55 (24.8) | 211 (36.2) | 215 (31.2) | 46 (17.3) |
| 1 | 92 (41.4) | 238 (40.8) | 277 (40.1) | 114 (42.9) |
| 2–4 | 75 (33.8) | 134 (23.0) | 198 (28.8) | 106 (39.8) |
| Postbronchodilator lung function | ||||
| FEV1% predicted† | 56.5 (18.2) | 63.0 (16.8) | 62.7 (16.2) | 61.1 (13.4) |
| FVC (litres)† | 3.2 (0.96) | 3.4 (1.00) | 3.4 (1.00) | 3.1 (0.92) |
| FEV1/FVC† | 0.54 (0.11) | 0.57 (0.10) | 0.59 (0.09) | 0.62 (0.07) |
Figures are number and percentage unless stated otherwise.
*All differences between groups were significant (p<0.01).
†Mean (SD).
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; MRC, Medical Research Council.