[1] Natl & Kapodistrian Univ Athens, Aghia Sophia Childrens Hosp, Ctr Adolescent Med, Athens 11527, Greece
[2] Natl & Kapodistrian Univ Athens, Aghia Sophia Childrens Hosp, Sch Med, Dept Pediat 1,UNESCO Chair Adolescent Hlth Care, Athens 11527, Greece
[3] Gen Hosp Piraeus Aghios Panteleimon, Dept Pediat, Piraeus 18454, Greece
[4] Natl & Kapodistrian Univ Athens, Aretaieion Hosp, Sch Med, Unit Endocrinol Diabet Mellitus & Metab, Athens 11528, Greece
[5] Natl & Kapodistrian Univ Athens, Sch Med, Dept Pediat 1, Div Infect Dis, Athens 11527, Greece
[6] Natl & Kapodistrian Univ Athens, Aghia Sophia Childrens Hosp, Sch Med, Dept Pediat 1,Unit Clin & Translat Res Endocrinol, Athens 11527, Greece