1 Department of Clinical Biochemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark. Electronic address: jpg@dadlnet.dk.
2 Division of Cardiovascular Medicine, Linköping University, Sweden.
3 Medical Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark.
4 Department of Clinical Biochemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark.