1. Department of Endocrinology and Metabolic Diseases (F.R., N.R.B., M.F., J.A.R.), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
2. Department of Statistics (D.M.K.), University of Virginia, Charlottesville, Virginia 22904
3. Endocrine Research Unit (J.D.V.), Mayo Medical and Graduate Schools, Clinical Translational Research Center, Mayo Clinic, Rochester, Minnesota 55905