Characteristics of study participants (n = 535, 50% men)*
| Variable | ECRHS I(1992) | ECRHS II(2000) |
|---|---|---|
| BMI, body mass index; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; LDL, low density lipoprotein. | ||
| *Quantitative variables are mean (SD). | ||
| †Subjects who answered “yes” to at least one of the two questions: “Have you had an attack of asthma in the last 12 months?” and “Are you currently taking any medicine including inhalers, aerosols or tablets for asthma?” | ||
| ‡Subjects who answered “yes” to the two questions: “Do you usually cough during the day, or at night, in the winter?” and “Do you cough like this on most days for as much as three months each year?” | ||
| §Subjects who answered “yes” to the two questions : “Do you usually bring up any phlegm from your chest during the day, or at night, in the winter?” and “Do you bring up phlegm like this on most days for as much as three months each year?” | ||
| Age (years) | 36.9 (7.1) | 45.2 (7.1) |
| Smoking status (%) | ||
| Never smokers | 41.9 | 40.0 |
| Former smokers | 25.6 | 30.4 |
| Moderate smokers (<20 cigs/day) | 20.8 | 19.9 |
| Heavy smokers (⩾20 cigs/day) | 11.8 | 9.6 |
| BMI (%) | ||
| Underweight (<20 kg/m2) | 16.4 | 10.8 |
| Normal (20–24.9 kg/m2) | 63.9 | 56.8 |
| Overweight (25–29.9 kg/m2) | 17.6 | 25.8 |
| Obese (⩾30 kg/m2) | 2.1 | 6.6 |
| Current asthma (%) † | 5.6 | 6.4 |
| Chronic cough (%)‡ | 7.5 | 5.1 |
| Chronic sputum (%)§ | 4.5 | 5.2 |
| FEV1 (l/s) | 3.67 (0.82) | 3.42 (0.79) |
| FEV1 (% predicted) | 105.3 (13.5) | 104.9 (14.3) |
| FEV1/FVC <70% (%) | 4.3 | 5.2 |
| Serum β-carotene (μmol/l) | 0.40 (0.31) | 0.64 (0.48) |
| Serum α-carotene (μmol/l) | 0.096 (0.10) | 0.13 (0.11) |
| Serum vitamin A (μmol/l) | 1.91 (0.53) | 2.02 (0.56) |
| Serum vitamin E (μmol/l) | 23.0 (7.2) | 29.0 (7.6) |
| Serum LDL cholesterol (g/l) | 1.33 (0.40) | 1.32 (0.36) |