Insulin-like growth factor-I: clinical studies.

Insulin-like growth factor-I (IGF-I) has endocrine, autocrine and paracrine properties. Receptors for IGF-I are present on virtually all cell types but are located mainly on cells of mesenchymal origin, such as fibroblasts, chondrocytes and osteoblasts. Growth hormone (GH)-dependent and GH-independent actions of IGF-I have been implicated in normal and abnormal bone growth, diabetes mellitus, malnutrition, cancer, thyroid disease and hematological diseases. The availability of recombinant human IGF-I (rhIGF-I) has led to new treatments for GH-resistant Laron dwarfism and certain diseases associated with severe insulin resistance. IGF-I has recently been investigated as a neurotrophic factor. Phase II efficacy trials with patients with neurological disease such as traumatic brain injury, myotonic dystrophy and amyotrophic lateral sclerosis have shown that rhIGF-I has efficacy on various outcome parameters. Treatment with rhIGF-I may result in reversible side effects of which increased heart rate, papilledema, ophthalmologic and intracranial hypertension, facial and generalized edema, and weight gain are noteworthy.