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Three year IGF-I treatment of children with Laron syndrome
1Endocrinology and Diabetes Research Unit, Schneider Children's Medical Center of Israel, Petah Tiqva, Israel.
Insights
Insulin-like Growth Factor I (IGF-I) effectively treats Laron syndrome in children, significantly increasing growth velocity and improving metabolic markers. This IGF-I therapy mimics growth hormone effects, offering a viable treatment for IGF-I deficiency.
Area of Science:
- Pediatric Endocrinology
- Metabolic Disorders
- Growth Hormone Axis
Background:
- Laron syndrome is a rare genetic disorder characterized by insulin receptor (IGF-I) deficiency.
- Children with Laron syndrome exhibit severe growth retardation due to impaired IGF-I signaling.
Purpose of the Study:
- To evaluate the efficacy and safety of insulin-like growth factor I (IGF-I) as a replacement therapy in prepubertal children with Laron syndrome.
- To assess the impact of IGF-I treatment on linear growth, bone maturation, body composition, and metabolic parameters.
Main Methods:
- Nine prepubertal children with Laron syndrome received daily subcutaneous injections of IGF-I (150-200 micrograms/kg) for up to three years.
- Linear growth velocity, bone age, subcutaneous fat, body weight, and serum biochemical markers were monitored throughout the study.
Main Results:
- A significant increase in mean linear growth velocity was observed during the first year of IGF-I treatment (4.7 to 8.2 cm/yr), with sustained significant growth in subsequent years.
- Bone maturation progressed proportionally with chronological age, and a reduction in subcutaneous fat was noted despite weight gain.
- Metabolic improvements included better tolerance to fasting and increased serum alkaline phosphatase, phosphorus, and procollagens.
Conclusions:
- IGF-I is an effective replacement therapy for children with IGF-I deficiency (Laron syndrome), promoting linear growth and improving metabolic status.
- IGF-I treatment successfully mimics many of the anabolic and metabolic effects of growth hormone in this patient population.
- Long-term IGF-I therapy demonstrates safety and efficacy in managing growth and metabolic complications associated with Laron syndrome.
Abstract:
Nine prepubertal children with Laron syndrome (6 males, 3 females) aged 0.5 to 14.6 years were treated by daily subcutaneous injections of IGF-I in doses of 150-200 micrograms/kg. All patients completed at least one year of treatment; six completed two years and five three years. During the first year, a significant increase in linear growth velocity, from a mean +/- SD of 4.7 +/- 1.3 to 8.2 +/- 0.8 cm/yr (p < 0.0001), was registered. In the second year the growth velocity was lower, but still significantly higher than before treatment. Bone maturation advanced proportionally with chronological age. A reduction in subcutaneous fat tissue was observed despite the body weight increase. There was no aggravation of the characteristic hypoglycemic episodes; on the contrary, there was a better tolerance to fasting. Significant increases in serum alkaline phosphatase, phosphorus and procollagens were registered throughout the study. In conclusion, IGF-I provides an effective replacement treatment for IGF-I-deficient children, mimicking most effects ascribed to growth hormone.