1. Institute of Clinical Medicine, University of Oslo, Oslo, Norway;
2. Department of Vascular Surgery, Division of Cardiovascular and Pulmonary Diseases, Oslo University Hospital, Oslo, Norway;
3. Hormone Laboratory, Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway;
4. Department of Vascular Surgery, Østfold Central Hospital, Kalnes, Norway;
5. Department of Vascular Surgery, Sørlandet Hospital HF, Kristiansand, Norway;
6. Oslo Center for Biostatistics and Epidemiology (OCBE), Oslo University Hospital, Oslo, Norway