Table 2 Baseline characteristics classified by the presence of nicotine dependence
From: Epidemiology, radiology, and genetics of nicotine dependence in COPD
Variables | No/Low dependence (n = 513) | High dependence (n = 329) | p | |
|---|---|---|---|---|
Subjects | Control | 311(61.3) | 196 (38.7) | 0.76 |
COPD | 202(60.3) | 133(39.7) | ||
COPD stage | GOLD II | 116(55.0) | 95(45.0) | 0.02 |
GOLD III | 66(66.7) | 33(33.3) | ||
GOLD IV | 20(80.0) | 5(20.0) | ||
Spirometry | ||||
FEV1/FVC % | Control | 0.79 ± 0.05 | 0.79 ± 0.05 | 0.25 |
COPD | 0.52 ± 0.13 | 0.54 ± 0.11 | 0.03 | |
FEV1pred % | Control | 98.5 ± 12.5 | 96.3 ± 11.9 | 0.047 |
COPD | 53.5 ± 17.2 | 57.8 ± 14.7 | 0.02 | |
Demographic | ||||
Age, year | Control | 54.8 ± 7.4 | 52.3 ± 5.8 | <.0001 |
COPD | 60.0 ± 8.0 | 57.9 ± 7.5 | 0.02 | |
Male, n (%) | Control | 158(50.8) | 118(60.2) | 0.04 |
COPD | 107(53.0) | 78(58.7) | 0.31 | |
White, n (%) | Control | 147(47.3) | 98(50.0) | 0.55 |
COPD | 135(66.8) | 109(82.0) | 0.002 | |
Smoking related | ||||
Pack-years of smoking | Control | 32.2 ± 15.6 | 45.2 ± 21.5 | <.0001 |
COPD | 45.8 ± 23.4 | 60.6 ± 33.7 | <.0001 | |
Average number of cigarettes smoked per day | Control | 17.3 ± 7.4 | 24.8 ± 9.2 | <.0001 |
COPD | 21.0 ± 8.7 | 28.1 ± 12.2 | <.0001 | |
Cigarettes/day, current | Control | 12.7 ± 7.3 | 23.6 ± 9.7 | <.0001 |
COPD | 12.4 ± 7.8 | 24.8 ± 10.5 | <.0001 | |
Smoking starting age, years | Control | 17.5 ± 5.5 | 16.2 ± 4.9 | 0.01 |
COPD | 17.0 ± 4.9 | 15.5 ± 4.6 | 0.01 | |
Symptom | ||||
Chronic bronchitis symptoms*, n (%) | Control | 49(15.8) | 43(21.9) | 0.08 |
COPD | 64 (31.7) | 72(54.1) | <.0001 | |
Radiographic | ||||
% Emphysema at -950 HU, % | Control | 2.1 ± 2.4 | 1.5 ± 1.9 | 0.01 |
COPD | 10.5 ± 10.8 | 6.2 ± 7.1 | <.0001 | |
% Gas trapping, % | Control | 10.7 ± 9.9 | 10.1 ± 9.9 | 0.52 |
COPD | 36.0 ± 20.6 | 28.3 ± 16.3 | 0.001 | |
Pi10 | Control | 3.75 ± 0.13 | 3.75 ± 0.11 | 0.72 |
COPD | 3.80 ± 0.12 | 3.83 ± 0.12 | 0.11 | |