Table 1.
Characteristics of the study populations
| Grade I | Grade II | Grade III | Grade IV | P-value | |
|---|---|---|---|---|---|
| Number (%) | 93 (21) | 205 (46) | 114 (26) | 33 (7) | |
| Female (%) | 11 (12) | 20 (10) | 5 (4) | 2 (6) | |
| Age, years | 71.6±8.1 | 72.8±8.4 | 72.8±7.7 | 72.3±7.9 | ns |
| Smoking index, pack-years | 53.0±31.5 | 53.7±27.6* | 63.9±31.2 | 54.0±28.0 | 0.02 |
| Current smokers (%) | 9 (10) | 30 (15) | 15 (13) | 4 (13) | ns |
| BMI, kg/m2 | 22.9±2.9*,# | 22.9±3.2*,# | 21.7±3.5# | 19.9±2.9 | <0.0001 |
| FEV1/FVC (%) | 63.3±4.9 | 55.4±8.2 | 41.1±9.3 | 32.8±8.1 | <0.0001 |
| FEV1, mL | 2,379±453 | 1,720±400 | 1,069±224 | 633±120 | <0.0001 |
| %FEV1 | 91.2±9.7 | 65.3±8 | 40.4±6 | 24.2±3.2 | <0.0001 |
Notes: Data are presented as mean ± standard deviation.
*
P<0.05 vs Grade III,
#
P<0.05 vs Grade IV.
Abbreviations: BMI, body mass index; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; ns, not significant.