TABLE 1

Basic characteristics of the study population

Subjects3942
Normal spirometry2843 (72.1%)
COPD grade 1319 (8.1%)
COPD grade 2305 (7.7%)
COPD grade 343 (1.1%)
COPD grade 412 (0.3%)
All COPD679 (17.2%)
Restrictive spirometric pattern420 (10.7%)
Never-smokers1595 (40.5%)
Former smokers1481 (37.6%)
Smokers819 (20.8%)
Underweight#102 (2.6%)
Normal weight1402 (35.6%)
Pre-obesity+1721 (43.7%)
Obesity§719 (18.2%)
Coronary artery disease521 (13.2%)
Heart failure51 (1.3%)
Arrhythmia238 (6.0%)
Hypertension1369 (34.7%)
Claudication151 (3.8%)
Diabetes357 (9.1%)
Wheeze most days a week424 (10.8%)
mMRC dyspnoea score ≥2668 (16.9%)
Chronic productive cough1072 (27.2%)
Any inhaled steroids897 (22.8%)
Any oral steroids301 (7.6%)
Professionals or executives1003 (25.4%)
Assistant nonmanual employees645 (16.4%)
Manual workers in industry768 (19.5%)
Manual workers in services1144 (29.0%)
Self-employed nonprofessionals236 (6.0%)
Other occupations146 (3.7%)
  • COPD: chronic obstructive pulmonary disease; mMRC: modified Medical Research Council. #: body mass index (BMI) <20; : 20≤BMI<25; +: 25≤BMI<30; §: BMI≥30.