1. Department of Endocrinology and Metabolism (F.R., H.P., P.K., N.R.B., A.M.P.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
2. Department of Endocrinology (E.E., E.F.), Amsterdam Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
3. Endocrine Research Unit (J.D.V.), Mayo Clinic College of Medicine, Rochester, Minnesota 55905