1. Section of Epidemiology, Department of Public Health, University of Copenhagen , Øster Farimagsgade 5, Post Box 2099, 1014 Copenhagen , Denmark
2. Steno Diabetes Center Copenhagen, Copenhagen University Hospital , Borgmester Ib Juuls Vej 83, 2730 Herlev , Denmark
3. Department of Clinical Medicine, Aalborg University , Søndre Skovvej 15, 9000 Aalborg , Denmark