1. Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
2. Department of Cardiology, Tjongerschans Hospital, Heerenveen, the Netherlands
3. Department of Endocrinology, Leiden University Medical Centre, Leiden, the Netherlands
4. Department of Nephrology, Leiden University Medical Centre, Leiden, the Netherlands
5. Department of Internal Medicine, University Medical Centre Groningen, Groningen, the Netherlands
6. Department of Internal Medicine, Isala Clinics, Zwolle, the Netherlands