The effect of treatment with somatostatin analogs in children with neurofibromatosis type 1 and growth hormone excess.

CONTEXT: Growth hormone (GH) excess in children is rare but may be seen in children with neurofibromatosis type 1 (NF1) and is then often associated with optic pathway glioma (OPG).

OBJECTIVE

The aim of this study was to determine anthropometrics and the efficacy of treatment in patients with NF1 and GH excess. Additionally, to examine the association between GH excess and OPG.

DESIGN

A descriptive, retrospective study on nine patients with NF1 and GH excess referred to a tertiary center of pediatric endocrinology.

SETTING

Single tertiary center.

PATIENTS: Nine patients with GH excess and NF1 were routinely followed by pediatric endocrinologists for clinical evaluation, anthropometrics, and hormone analysis. All patients underwent brain Magnetic Resonance Imaging (MRI) and all the scans were reevaluated for classification of the OPGs. Furthermore, the patients were routinely followed by ophthalmologists.

MAIN OUTCOME MEASURES: Anthropometrics and IGF-I levels expressed as standard deviation scores (SDS).

RESULTS

The patients presented with height velocity (HV) (SDS), height (SDS) and IGF-I (SDS) above the normal reference range. Eight out of nine patients had OPGs, seven of which with hypothalamic involvement. They were treated with somatostatin analogs (SSas). Within the first year of treatment, IGF-I (SDS) levels decreased rapidly and normalized in all patients within two to three and a half years.

CONCLUSION

Rapid growth in children with NF1 requires further evaluation especially in those with OPG since it could be a caused by GH excess. Treatment of GH excess with SSas was effective.