Effect of Different Forms of Insulin-Like Growth Factor Treatment on Growth in Children With Growth Hormone Insensitivity Syndrome

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 624-646-Growth: Clinical Trials & Observational Studies
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-625
Alev Ozon*1, E. Nazli Gonc2, Ayfer Karabulut Alikasifoglu3 and Nurgun Kandemir2
1Hacettepe Univ Med Faculty, Ankara, Turkey, 2Hacettepe University Faculty of Medicine, Ankara, Turkey, 3Hacettepe Univ-School of Med, Ankara, Turkey
Background: Growth hormone insensitivity syndrome (GHIS) is caused by a defective growth hormone receptor (GHR). It is characterized by growth failure starting in infancy, severe short stature unresponsive to rhGH, characteristic dysmorphic features, elevated GH levels and severe deficiency of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3).  We studied the effects of treatment with IGF-I either in a molar complex with IGFBP-3 (rhIGF-I/IGFBP-3) or with IGF-I alone (rhIGF-I) on linear growth in 8 children (5 boys) with GHIS.

Methods: All children received combined rhIGF-I/IGFBP-3 treatment of 1-2 mg/kg/d for one to two years followed by a period of no treatment and received rhIGF-I alone for one or more years. Their linear growth before any treatment, during and in between the two treatment modalities were compared. Factors that may affect  linear growth i.e. age, pubertal stage and BMI are also analyzed.

Results: Annual growth rate improved from a mean of 3 cm/year (no treatment) into 6,8 and 6,3 cm/year (combined rhIGF-I/IGFBP-3 vs IGF-I alone, respectively) with growth factor treatment. Height SDS increased from -7.61 at baseline to -7.22 with combined treatment in the first year, which decreased to -7.78 after discontinuation of treatment. Height SDS increased again from -7.78 to -7.43 with IGF-I alone in one year. Although both treatments improved height velocity SDS significantly in comparison to baseline, there was no significant difference in effect between the two treatments. The growth response was partially affected by body mass index.

Conclusion: Two different forms of IGF-I promote growth in children with GHIS with a response similar to each other, however less than that observed in growth hormone deficient children with GH replacement.

Nothing to Disclose: AO, ENG, AKA, NK

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