1. Department of Endocrinology and Metabolic Diseases (O.M.D., N.R.B., A.M.P., F.R., M.O.v.A., J.A.R.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
2. Department of Clinical Epidemiology (O.M.D.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
3. Department of Neurosurgery (J.H.C.V.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands