2000 dairy workers and 2000 subjects without any occupational exposure, all aged 40 to 74 years, will take part to a COPD screening program (spirometry and bronchodilation test) between September 2011 and October 2014.
Subjects with COPD and healthy matched controls will attend a second visit. If needed, COPD subjects will be asked to stop any respiratory related medication such as short and long acting bronchodilators 72 hours prior to the visit. All subjects will complete several questionnaires (quality of life, respiratory symptoms, smoking habits,…). A complete medical history will be collected, and a blood sample will be taken. Subjects thereafter will complete arterial stiffness measurement, exhaled nitric oxide and pulmonary function testing pre- and 30-min post-bronchodilator. A symptom-limited incremental cycle exercise test will be performed on the same day, at least 6 hours after the bronchodilator test and at least 4 hours after the meal.
Exposure to organic dusts will be quantified through analyze of electrostatic wipes left at subjects' homes for 10 weeks.
