Further Observations on the Effects of Long-Term Treatment with Recombinant Human Insulin-Like Growth Factor 1 in Growth Hormone Insensitivity Syndrome

Abstract

Background/Aim: Growth hormone insensitivity syndrome (GHIS) is a spectrum of disorders. Laron syndrome was the earliest discovered. Insulin-like growth factor 1 (IGF-1) therapy is used to improve growth. IGF-1 has diverse effects on the growth of body organs. We aim to assess the long-term effects of IGF-1 therapy in patients with GHIS particularly on adiposity and acral growth. Methods: Six patients (5 with Laron syndrome and 1 with type 1A growth hormone deficiency) were followed for a mean (±SD) of 8.2 ± 1.8 years. Mean age at start of therapy was 7.6 ± 4.1 years. Anthropometric evaluation including growth of hand, foot, ear, and skin folds, and assessment of internal organ growth were done. Results: Hand and foot sizes improved significantly, especially when treatment was initiated early. Prominent effects on adiposity were observed, reflected by increment in body mass index standard deviation score (SDS) and skin fold SDS. Mean height, height velocity, sitting height, and head circumference SDS improved with therapy. A significant increase in spleen and right kidney was appreciated. Conclusion: IGF-1 therapy improves growth in GHIS. The hand and foot sizes increase significantly with therapy, and can even normalize with early initiation of treatment. Ear length further improves with therapy. Other effects include increase in adiposity and internal organ growth.