1. Dutch Growth Research Foundation (E.P.C.S., R.F.A.d.L.v.W., A.C.S.H.-K.), 3016 AH Rotterdam, The Netherlands
2. Department of Pediatrics (E.P.C.S., R.F.A.d.L.v.W., A.C.S.H.-K.), Division of Endocrinology, Erasmus University Medical Center Rotterdam/Sophia Children's Hospital, 3015 GJ Rotterdam, The Netherlands
3. Department of Pediatric Endocrinology (B.J.O.), Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
4. Department of Internal Medicine (F.H.d.J.), Erasmus University Medical Center, 3015 CE Rotterdam, The Netherlands