1. Unit of Medical Epidemiology, Department of Surgical Sciences Uppsala University Uppsala Sweden
2. Unit of Cardiovascular and Nutritional Epidemiology Institute of Environmental Medicine, Karolinska Institutet Stockholm Sweden
3. Department of Medicine University of North Carolina School of Medicine Chapel Hill North Carolina USA
4. Department of Epidemiology, Gillings School of Global Public Health University of North Carolina Chapel Hill North Carolina USA
5. Department of Medical Sciences, Respiratory, Allergy and Sleep Research Uppsala University Uppsala Sweden