ESPE Abstracts

Background: Idiopathic short stature (ISS) is defined as short stature of unknown origin. It is apparently not associated with GH deficiency (GHD). High-dose GH treatment is considered to be more beneficial in children with ISS than in those with GHD. However, responses to GH in children with ISS are highly variable and dose-dependent, and the optimal treatment is controversial.

Aims: To compare the effects of low-dose GH treatment in children with GHD vs ISS.

Methods: This retrospective study was conducted at Ajou University Hospital, Korea. Patients diagnosed with GHD (n=66) or ISS (n=35) and subsequently treated with low-dose GH over a 2-year period (0.22 mg/kg per week, six times per week) were evaluated. We reviewed their auxological data, laboratory findings, and responses to GH and analysed the clinical factors associated with 1st year changes in the height SDS and growth velocity.

Results: No differences were observed in the pretreatment height SDS, IGFBP3 SDS, mid-parental height, BMI, or bone age delay between the GHD and ISS groups. However, the ISS group had a higher IGF1 SDS and stimulated peak GH levels than did the GHD group. Low-dose GH did not affect the growth velocity in the ISS group, although a significantly greater 1st-year Δ height SDS was observed in the ISS group than in the GHD group (0.82±0.32 and 0.67±0.31, respectively; P<0.05). Age was negatively associated with first-year growth velocity and Δ height SDS in both groups.

Conclusions: Low-dose GH was similarly effective between children with ISS and GHD. Early intervention with GH is the most appropriate therapeutic option to obtain optimal responses in both ISS and GHD.