Table 1.
The distribution of demographic characteristics for all subjects and those in the two nested case control study groups in the LHS.
| All participants (N = 1488) | Rate of decline study | Baseline lung function study | |||||
|---|---|---|---|---|---|---|---|
| Fast Decliners (n = 266) | Non Decliners (n = 293) | p value | High Function (n = 532) | Low Function (n = 527) | p value | ||
| Men/Women | 948/540 | 158/108 | 197/96 | N/A | 352/180 | 325/202 | N/A |
| Age (years) | 48.41 (0.177) | 49.47 (0.397) | 47.48 (0.399) | <0.001 | 46.21 (0.772) | 50.76 (0.262) | <0.001 |
| Smoking history (pack-yrs)* | 40.41 (0.483) | 43.23 (1.178) | 38.35 (1.064) | 0.002 | 35.33 (0.125) | 45.24 (0.809) | <0.001 |
| Smoking status during 5 years follow-up† | |||||||
| Continuing smokers | 979 | 266 | 293 | N/A | 264 | 286 | N/A |
| Intermittent quitters | 315 | N/A | N/A | N/A | 157 | 158 | N/A |
| Sustained quitters | 194 | N/A | N/A | N/A | 111 | 83 | N/A |
| Body Mass Index (kg/m2) | 25.49 (0.099) | 25.22 (0.248) | 25.77 (0.210) | 0.091 | 25.39 (0.150) | 25.57 (0.183) | 0.455 |
| ΔFEV1/yr (% predicted pre)‡ | −0.98 (0.053) | −4.13 (0.066) | 1.087 (0.042) | <0.001 | −0.55 (0.067) | −1.22 (0.078) | <0.001 |
| ΔFEV1/yr (% predicted post)§ | −0.85 (0.04) | −3.44 (0.078) | 0.695 (0.054) | <0.001 | −0.75 (0.064) | −0.74 (0.078) | 0.949 |
| Baseline FEV1 (% predicted pre)∥ | 74.15 (0.302) | 72.68 (0.542) | 75.51 (0.472) | <0.001 | 86.49 (0.125) | 61.07 (0.180) | <0.001 |
| Baseline FEV1 (% predicted post)** | 77.57 (0.336) | 75.00 (0.561) | 79.80 (0.467) | <0.001 | 91.81 (0.099) | 62.57 (0.144) | <0.001 |
| IL6 concentration (pg/ml) | 2.60 (1.80–4.20) | 2.75 (2.00, 4.03) | 2.70 (1.70, 4.50) | 0.1840 | 2.50 (1.70, 3.90) | 2.70 (1.85, 4.55) | 0.12 |
Values are means (SEM) for continuous data.
Number of packs of cigarettes smoked per day × number of years smoking.
Continuing smokers: participants who reported smoking at each annual visit. Sustained quitters: participants who were validated by salivary cotinine or exhaled CO as abstinent at every annual visit. Intermittent quitters: participants who were not sustained quitters or continuing smokers
Change in lung function over a 5-year period per year as % predicted FEV1 pre bronchodilator
Change in lung function over a 5-year period per year as % predicted FEV1 post bronchodilator
Lung function at the start of the Lung Health Study as measured by FEV1(%) predicted pre bronchodilator
Lung function at the start of the Lung Health Study as measured by FEV1(%) predicted post bronchodilator.