1. Department of Respiratory Medicine,
2. The Copenhagen General Population Study, and
3. Department of Clinical Medicine, Faculty of Health and Medical Sciences, and
4. Department of Public Health, Section of Epidemiology, University of Copenhagen, Copenhagen, Denmark; and
5. Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
6. Department of Clinical Biochemistry, Copenhagen University Hospital – Herlev and Gentofte, Copenhagen, Denmark;