Table 1.
Study participant distribution according to the GOLD standards
| Study groups by pack years and air flow limitation | Pack years 1 pack year = 20 cigarettes a day in 1 year | Airflow limitation FEV1/FVC < 70 % |
|---|---|---|
| Healthy never smokers n = 50 | 0 | No |
| Healthy smokers/ex-smokers n = 25 | <20 | No |
| At risk smokers/ex-smokers n = 25 | >20 | No |
| GOLD stage 1 smokers/ex-smokers n = 75 | >20 | FEV1 ≥ 80 % |
| GOLD stage 2 smokers/ex-smokers n = 75 | >20 | 50 % ≤ FEV1 < 80 % |
| GOLD stage 3 smokers/ex-smokers n = 25 | >20 | 30 % ≤ FEV1 < 50 % |
| GOLD stage 4 smokers/ex-smokers n = 25 | >20 | FEV1 < 30 % |
The enrolled subjects will be divided in the following study groups. The total number of participants will be 300, including 50 healthy never smokers, 25 healthy smokers and ex-smokers, 25 at risk smokers and ex-smokers, 200 participants with GOLD stage 1–4 divided in 75 with GOLD stage 1 and 2 respectively (smokers and ex-smokers) and 25 with GOLD stage 3 and 4 respectively COPD participants (smokers and ex-smokers)