Characteristics of 1097 people from the middle-aged general population by presence of breathlessness
| Variable | With breathlessness (mMRC ≥1) n=108 | Without breathlessness (mMRC=0) n=989 | P value |
| Age, mean years (SD) | 59.1 (4) | 57.5 (4) | <0.001 |
| Female, n (%) | 71 (66) | 477 (48) | 0.001 |
| Low socioeconomic status, n (%) | 80 (74) | 461 (47) | <0.001 |
| BMI, kg/m2, mean (SD) | 30.2 (6) | 26.9 (4) | <0.001 |
| Pack years of smoking, mean years (SD) | 16.9 (30) | 9.3 (13.6) | <0.001 |
| Smoking status, n (%) | 0.069 | ||
| Never | 37 (34) | 441 (45) | |
| Current | 26 (24) | 169 (17) | |
| Former | 45 (42) | 379 (38) | |
| Fitness- Ekblom-Bak (mL/min/kg), mean (SD) (missing=441) | 30.7 (7) | 35.4 (7) | <0.001 |
| Low aerobic fitness*, n (%) (missing=441) | 14 (33) | 63 (10) | <0.001 |
| FEV1, L (SD) (missing=15) | 2.6 (0.6) | 3.3 (0.75) | <0.001 |
| FEV1, % of predicted (SD) | 84 (23) | 102 (23) | <0.001 |
| FVC, L (SD) (missing=15) | 3.5 (0.8) | 4.2 (1) | <0.001 |
| FVC, % of predicted (SD) | 88 (24) | 103 (24) | <0.001 |
| FEV1/FVC (SD) (missing=22) | 0.75 (0.1) | 0.78 (0.6) | <0.001 |
| FEV1/FVC, % of predicted (SD) (missing=22) | 93 (14) | 98 (8) | <0.001 |
| Chronic airflow limitation (FEV1 <LLN), n (%) (missing=22) | 24 (23) | 109 (11) | 0.001 |
| Restriction (TLC <LLN) (missing=45) | 9 (9.1) | 68 (7.1) | 0.48 |
| Respiratory disease, n (%) (missing=34) | 58 (57) | 341 (35) | 0.001 |
| Asthma, n (%) (missing=15) | 26 (24) | 72 (7) | <0.001 |
| COPD, n (%) (missing=15) | 12 (11.2) | 12 (1.2) | <0.001 |
| Chronic bronchitis, n (%) (missing=41) | 21 (20) | 60 (6) | <0.001 |
| Heart disease or chest pain, n (%) (missing=47) | 35 (35) | 59 (6) | <0.001 |
| Atrial fibrillation/flutter, n (%) (missing=17) | 2 (2) | 7 (0.7) | 0.19 |
| Angina pectoris, n (%) (missing=22) | 30 (30) | 38 (4) | <0.001 |
| Coronary heart disease, n (%), (missing=21) | 4 (4) | 15 (1.5) | 0.24 |
| Heart failure, n (%) (missing=29) | 3 (3.8) | 5 (0.5) | 0.094 |
| Anxiety or depression, n (%) (missing=9) | 56 (52) | 228 (23) | <0.001 |
| Anxiety, n (%) (missing=22) | 39 (36) | 188 (19) | <0.001 |
| Depression, n (%) (missing=32) | 33 (31) | 89 (9) | <0.001 |
| Anaemia, n (%) (missing=8) | 1 (1) | 9 (1) | 0.96 |
| Obesity, n (%) | 46 (43) | 190 (19) | <0.001 |
Obesity=BMI>30.
*Subcohort with measured exercise capacity using the Ekblom-Bak test (n=656), defined as having a score of 28 or less for men aged 50–59 years, 23 or less for men aged 60 years or higher, 26 or less for women aged 50–59 years or a score of 22 or lower for women aged 60 years or higher.
BMI, body mass index; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume during 1 s; FVC, functional vital capacity; LLN, lower limit of normal; mMRC, modified Medical Research Council; TLC, total lung capacity.