1. Department of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden;
2. Department of Cancer Research and Molecular Medicine, Faculty of Medicine, the Norwegian University of Science and Technology, Trondheim, Norway;
3. Department of Endocrinology, St. Olav University Hospital, Trondheim, Norway;
4. Nord-Trøndelag Health Study Research Centre, Department of Community Medicine and General Practice, Faculty of Medicine, The Norwegian University of Science and Technology, Levanger, Norway.