1. Institute for Research in Extramural Medicine, Vrije University Medical Center, Amsterdam, the Netherlands
2. Department of Clinical Epidemiology and Biostatistics, Vrije University Medical Center, Amsterdam, the Netherlands
3. Public Health Division, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
4. Department of Internal Medicine, Vrije University Medical Center, Amsterdam, the Netherlands
5. Department of Endocrinology, Vrije University Medical Center, Amsterdam, the Netherlands