Table 2.
Baseline and follow-up characteristics of subjects who had spirometry in 1993 and 2013
| Males Mean (SD) (n=130) | Females Mean (SD) (n=132) | |
|---|---|---|
| Baseline characteristics (1993) | ||
| Age (years) | 35.6 (5.9) | 35.1 (6.4) |
| Weight (kg) | 80.3 (11.9) | 64.8 (11.9)* |
| BMI (kg/m2) | 25.8 (2.8) | 24.5 (4.1)† |
| FEV1 (L) | 4.02 (0.7) | 3.0 (0.4)* |
| (% predicted) | 94.7 (14.0) | 97.0 (11.5) |
| FVC (L) | 5.25 (0.77) | 3.82 (0.66)* |
| (% predicted) | 99.5 (11.5) | 102.4 (13.1) |
| FEV1/FVC (%) | 77 (7.2) | 79 (6.8)‡ |
| Smoking status (%) | ||
| Never smoked | 52.3 | 56.1 |
| Former smoker | 26.9 | 24.2 |
| Current smoker | 20.8 | 19.7 |
| Characteristics on follow-up (2013) | ||
| Age (years) | 55.4 (5.9) | 55.0 (6.3) |
| Age difference (years) | 19.8 (0.59) | 19.8 (0.58) |
| Weight (kg) | 87.4 (16.5) | 72.9 (16.3)* |
| Weight difference (kg) | 7.0 (9.1) | 8.1 (9.8) |
| BMI (kg/m2) | 27.9 (4.4) | 27.7 (5.9) |
| ΔBMI 1993–2013 (kg/m2) | 2.2 (2.97) | 3.2 (3.8)** |
| FEV1(L) | 3.61 (0.68) | 2.52 (0.46)* |
| FVC (L) | 4.84 (0.8) | 3.35 (0.6)* |
| ΔFEV1 in mL/year | 21.4 (19.4) | 24.7 (14.4) |
| ΔFVC in mL/year | 21.1 (20.1) | 24.7 (20.2) |
| FEV1/FVC decline (%) | 2.2 (5.0) | 3.4 (5.4) |
| Current smoker (%) | 6.9 | 7.7 |
| Pack-years for current smokers 2013 median (IQR) | 13.6 (11.0, 35.3) | 28.4 (7.8, 33.8) |
Notes:
*
P<0.001,
**
P=0.014,
†
P=0.004,
‡
P=0.006.
Abbreviations: ΔBMI, change in body mass index; ΔFEV1, rate of decline over time in forced expiratory volume in 1 second (mL/year); ΔFVC, rate of decline over time in forced vital capacity (mL/year); IQR, interquartile range; SD, standard deviation.