Table 1.
Demographics of Nonsmokers and Smokersa
| Parameter | Nonsmokers | Smokers | Smokers vs nonsmokers p value |
|---|---|---|---|
| n | 5 | 5 | |
| Gender (M/F) | 1/4 | 4/1 | 0.06 |
| Age (yr) | 33.4 ± 11.5 | 48.6 ± 8.1 | 0.05 |
| Race (B/W/H/O)b | 2/1/0/2 | 2/0/2/1 | 0.34 |
| Body mass index | 23.6 ± 2.0 | 23.4 ± 4.0 | 0.9 |
| Smoking history | |||
| Age of initiation | NA | 20.4 ± 4.8 | NA |
| Duration of smoking (pk-yr) | NA | 25.1 ± 15.3 | NA |
| Urine nicotine (ng/ml)c | < 2 | 640 ± 746 | 0.07 |
| Urine cotinine (ng/ml)c | < 5 | 925 ± 312 | 0.002 |
| Carboxyhemoglobin (%) | 1.6 ± 0.2 | 2.6 ± 0.33 | 0.0008 |
| Pulmonary function parametersd | |||
| FVC | 100.4 ± 17.4 | 114 ± 15.3 | 0.23 |
| FEV1 | 101.2 ± 12.6 | 115 ± 17.2 | 0.19 |
| % Change FEV1 post-bronchodilator | 3.2 ± 3.6 | 3.4 ± 2.2 | 0.92 |
| FEV1/FVC | 85.4 ± 5.0 | 81.6 ± 3.8 | 0.22 |
| TLC | 98.6 ± 15.3 | 98.8 ± 6.7 | 0.98 |
| DLCO | 86.6 ± 7.6 | 88.2 ± 8.4 | 0.76 |
| Cough Scoree | 0.6 ± 0.5 | 1 ± 1 | 0.46 |
| Sputum Scoree | 0.4 ± 0.5 | 1 ± 1 | 0.28 |
aData are presented as mean ± standard deviation, p values of numeric parameters calculated using a 2-tailed Student’s t-test with unequal variance, p value of categorical parameters calculated using a chi-square test for screening date
bAbbreviations: B=Black, W=White, H=Hispanic, O=Other, NA = not applicable
cUndetectable urine nicotine < 2 ng/ml; cotinine < 5 ng/ml
dPulmonary function testing parameters are given as % of predicted value with the exception of FEV1/FVC, which is reported as % observed; FVC - forced vital capacity, FEV1 - forced expiratory volume in 1 s, TLC -total lung capacity, DLCO - diffusing capacity
eCough and sputum score were each evaluated on a scale of 0–4: 0 = not at all; 1 = only with chest infections; 2 = a few days a month; 3 = several days per week; 4 = most days per wk. [35]