1. Intramural Research Program, Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Bethesda, Maryland
2. Icelandic Heart Association, Kopavogur, Iceland
3. Icelandic Heart Association, Kopavogur, Iceland3Faculty of Medicine, University of Iceland, Reykjavik, Iceland
4. Department of Radiology, Leiden University Medical Centre, Leiden, the Netherlands