Developing COPD: a 25 year follow up study of the general population
- 1Department of Cardiology and Respiratory Medicine, Hvidovre Hospital, Hvidovre, Denmark
- 2The Copenhagen City Heart Study, Bispebjerg Hospital, Copenhagen, Denmark
- 3North West Lung Centre, South Manchester University Hospital Trust, Manchester, UK
- Correspondence to:
Dr P Lange
Department of Cardiology and Respiratory Medicine, 253 Hvidovre Hospital, Kettegård Alle 30, DK-2650 Hvidovre, Denmark;
- Received 21 March 2006
- Accepted 22 May 2006
Background: Smokers are more prone to develop chronic obstructive pulmonary disease (COPD) than non-smokers, but this finding comes from studies spanning 10 years or less. The aim of this study was to determine the 25 year absolute risk of developing COPD in men and women from the general population.
Methods: As part of the Copenhagen City Heart Study, 8045 men and women aged 30–60 years with normal lung function at baseline were followed for 25 years. Lung function measurements were collected and mortality from COPD during the 25 year observation period was analysed.
Results: The percentage of men with normal lung function ranged from 96% of never smokers to 59% of continuous smokers; for women the proportions were 91% and 69%, respectively. The 25 year incidence of moderate and severe COPD was 20.7% and 3.6%, respectively, with no apparent difference between men and women. Smoking cessation, especially early in the follow up period, decreased the risk of developing COPD substantially compared with continuous smoking. During the follow up period there were 2912 deaths, 109 of which were from COPD. 92% of the COPD deaths occurred in subjects who were current smokers at the beginning of the follow up period.
Conclusion: The absolute risk of developing COPD among continuous smokers is at least 25%, which is larger than was previously estimated.
- COPD, chronic obstructive pulmonary disease
- FEV1, forced expiratory volume in 1 second
- FVC, forced vital capacity
This study was funded by the Danish Heart Foundation and Danish Lung Foundation.
Competing interests: none declared.