Table 1.
Characteristics of the subjects by age group
| Characteristics | All (n = 11,587) | Age group (years) | |||
|---|---|---|---|---|---|
| 40–49 (n = 3,803) | 50–59 (n = 4,539) | 60–69 (n = 2,451) | ≥70 (n = 794) | ||
| Age (years) | 54.6 ± 9.1 | 44.8 ± 2.9 | 54.7 ± 2.9 | 63.5 ± 2.9 | 74.2 ± 3.8 |
| BMI (kg/m2) | 23.7 ± 2.9 | 24.0 ± 3.1 | 23.8 ± 2.8 | 23.4 ± 2.6 | 23.0 ± 2.7 |
| FEV1 % predicted | 94.2 ± 11.2 | 94.2 ± 9.4 | 94.1 ± 10.7 | 94.3 ± 12.8 | 94.8 ± 16.2 |
| FEV1/FVC (%) | 78.5 ± 6.4 | 80.4 ± 5.4 | 78.7 ± 6.0 | 76.5 ± 6.7 | 74.2 ± 8.3 |
| Creatinine (mg/dL) | 0.12 ± 0.37 | 0.11 ± 0.31 | 0.11 ± 0.33 | 0.14 ± 0.49 | 0.14 ± 0.39 |
| Estimated GFR (mL/min/1.73 m2) | 74.3 ± 13.0 | 78.6 ± 12.0 | 74.4 ± 12.5 | 70.3 ± 12.6 | 65.6 ± 13.6 |
| CRP (mg/L) | 0.12 ± 0.37 | 0.11 ± 0.31 | 0.11 ± 0.33 | 0.14 ± 0.49 | 0.14 ± 0.39 |
| Hyper-LDL-cholesterolemia (%) | 32.5 | 31.4 | 33.1 | 32.6 | 33.2 |
| Hypertension (%) | 31.2 | 19.1 | 32.3 | 40.8 | 52.5 |
| Diabetes (%) | 9.9 | 5.2 | 11.0 | 14.2 | 12.3 |
| Medication | |||||
| Treatment for cholesterolemia (%) | 8.2 | 4.2 | 8.5 | 11.3 | 16.2 |
| Treatment for hypertension (%) | 19.2 | 7.5 | 19.9 | 29.0 | 41.1 |
| Treatment for diabetes (%) | 5.2 | 1.9 | 5.5 | 8.2 | 9.1 |
| Chronic kidney disease (%) | 10.6 | 3.1 | 9.5 | 17.4 | 31.5 |
| Airflow obstruction (%) | 7.9 | 3.1 | 6.4 | 13.6 | 22.0 |
| Lung function status (%) | |||||
| Normal lung function | 92.1 | 96.9 | 93.6 | 86.4 | 78.0 |
| GOLD stage I | 3.9 | 1.5 | 3.0 | 7.0 | 11.1 |
| GOLD stage II–IV | 4.0 | 1.6 | 3.4 | 6.6 | 10.9 |
| Smoking history (%) | |||||
| Never smokers | 31.8 | 32.1 | 27.4 | 36.1 | 42.4 |
| Former smokers | 38.0 | 27.7 | 40.5 | 46.3 | 47.1 |
| Current smokers | 30.2 | 40.2 | 32.1 | 17.7 | 10.5 |
| Pack-yearsa | 18.7 ± 20.0 | 14.4 ± 14.6 | 20.8 ± 20.2 | 21.2 ± 24.1 | 18.8 ± 23.1 |
| Alcohol intake (%) | |||||
| Non-drinkers | 23.8 | 25.5 | 22.0 | 22.9 | 29.1 |
| 1–2 days/week | 13.2 | 16.0 | 11.9 | 11.6 | 12.1 |
| 3–4 days/week | 11.2 | 11.7 | 11.6 | 9.9 | 10.6 |
| 5–6 days/week | 12.9 | 12.5 | 12.5 | 13.8 | 14.5 |
| Everyday drinkers | 38.9 | 34.3 | 42.0 | 41.8 | 33.8 |
| Regular physical activityb (%) | 36.1 | 24.3 | 32.4 | 52.0 | 66.2 |
Values are presented as the mean and, which appropriate, ± standard deviation (SD)
BMI Body mass index, FEV1 forced expiratory volume in 1 s, FEV1/FVC forced expiratory volume in 1 s/forced vital capacity, CRP C-reactive protein, GFR glomerular filtration rate, LDL low-density lipoprotein
aPack-years = (number of cigarettes smoked per day × number of years smoked)/20
bRegular physical activity was defined as exercising at least 2 times per week for at least 30 min per session throughout the year