ESPE Abstracts

Introduction: Normal growth hormone (GH) secretion after the attainment of final height (FH) is observed in the majority of GH-treated children with GH deficiency (GHD), however it is unclear when such normalization of GH secretion occurs.

The Aim: Of the study was to assess the incidence of transient GHD in retesting with respect to pediatric criteria in the patients with isolated GHD diagnosed in childhood, depending on the moment of GH therapy withdrawal.

Material and methods: 260 children with isolated GHD (height SDS <-2.0, GH peak in 2 stimulation tests <10.0 µg/l), who completed GH therapy before (Group PRE) or after (Group POST) the attainment of near-FH (bone age >16 years in boys, >14 years in girls, height velocity <2.5 cm/year) and have performed retesting (insulin tolerance test followed by 2^nd pharmacological test if GH peak <10.0 µg/l); GH peak >10.0 µg/l in retesting was diagnostic for transient GHD.

Results: Significant increase (P < 0.001) of GH peak in retesting with respect to pre-treatment values was found, with only a weak correlation between GH peaks before treatment and in retesting (r = 0.195, P < 0.05). Male predominance (66.54%) among treated patients was observed. Transient GHD was diagnosed significantly more frequently (P = 0.0008) in boys than in girls, while there was no significant difference in the incidence of transient GHD between Groups PRE and POST (P = 0.57). Special attention should be paid to non-responders (mainly the patients with transient GHD in POST Group) and to the patients with GH peak in retesting <3.0 µg/l (9 cases in PRE, only 1 in POST Group).

Conclusions: In the majority of children with isolated GHD normalization of GH secretion with respect to pediatric criteria occurs before the attainment of near-FH. Overrepresentation of boys and higher incidence of transient GHD in them suggests the possibility of overdiagnosing GHD in boys. Earlier retesting of GH secretion could help to avoid overtreatment of patients with transient GHD.