1 Dutch Growth Research Foundation, Rotterdam, The Netherlands. R.Kuppens@kindengroei.nl, R.Kuppens@erasmusmc.nl.
2 Erasmus University Medical Center-Sophia Children's Hospital, Department of Pediatrics, Subdivision of Endocrinology, Rotterdam, The Netherlands. R.Kuppens@kindengroei.nl, R.Kuppens@erasmusmc.nl.
3 Erasmus University Medical Center, Department of Internal Medicine, Rotterdam, The Netherlands.
4 Dutch Growth Research Foundation, Rotterdam, The Netherlands.
5 Erasmus University Medical Center-Sophia Children's Hospital, Department of Pediatrics, Subdivision of Endocrinology, Rotterdam, The Netherlands.