Determinants of the Appearance and Progression of Early-Onset Chronic Obstructive Pulmonary Disease in Young Adults. A Case-Control Study with Follow-up.

Introduction And Objectives: Determinants of chronic obstructive pulmonary disease (COPD) in the early stages of its natural history are not well known. Improving our knowledge of these factors will help to design interventions that can modify prognosis. Study objectives are: a) to characterize a COPD population of young adults aged 35-50 years from a multidimensional point of view; b) to compare these patients with smokers with normal lung function; and c) to create a cohort of young adults aged 35-50 years (smokers or former smokers), with and without COPD, who will be followed in the future to improve understanding of the natural history of the disease.

Participants And Method: This is a case-control multicenter study aimed at establishing a well-characterized cohort of young adults, smokers or former-smokers, with and without COPD, for subsequent follow-up. A total of 311 participants (101 cases and 210 controls) were selected from approximately 30 primary care settings and 12 hospitals in 8 Spanish regions. Subjects were smokers or former smokers (>10 pack-years) aged 35-50 years. Diagnosis of COPD was based on a post-bronchodilator result of FEV1/FVC<70%. The main study variables were: questionnaires on health, symptoms, exacerbations and daily physical activity, lung function tests, blood and sputum samples, and low-dose computed tomography. In the statistical analysis, COPD patient characteristics will be described and compared with control subjects using a logistic regression analysis.