^aDivision of Adolescent/Young Adult Medicine

^bDivision of Endocrinology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA

Correspondence to Sarah Pitts, MD, Division of Adolescent/Young Adult Medicine, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA. Tel: +1 617 355 3732; fax: +1 617 730 0184; e-mail: sarah.pitts@childrens.harvard.edu