Abstract
OBJECTIVE: Recombinant IGF-I is now available for the treatment of GH insensitivity (Laron syndrome). We have determined the effects of IGF-I on soft connective tissue and bone metabolism in a group of patients with this disorder.
PATIENTS AND DESIGN: Thirteen patients with Laron syndrome (LS) (8 children and 5 adults) were included in the study. The children with LS were treated with IGF-I for 3 years with daily doses of 150-200 micrograms/kg. The adult LS patients were treated for 9 months with daily doses of 50-120 micrograms/kg. Blood samples for procollagens were collected before, during and at the end of IGF-I treatment.
MEASUREMENTS: Serum levels of the carboxyterminal propeptide of type I procollagen (PICP), the aminoterminal propeptide of type III procollagen (PIIINP) and of the pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) were determined before and during IGF-I administration.
RESULTS: Untreated patients with LS had lower than normal serum levels of PICP and PIIINP for age. IGF-I treatment increased significantly the PIIINP levels in children from 7.2 +/- 2.8 (SD) to 12.5 +/- 2.2 micrograms/l (P < 0.001), and in adults from 2.7 +/- 1.0 to 8.4 +/- 3.6 micrograms/l (P < 0.001); serum PICP increased from 243 +/- 123 to 384 +/- 190 micrograms/l (P < 0.087) in children, and in adults from 43.4 +/- 8.1 to 135.8 +/- 41.9 micrograms/l (P < 0.001). ICTP levels in children increased from 9.7 +/- 3.7 to 14.3 +/- 5.9 micrograms/l (P < 0.001) and in adult patients levels increased from 3.6 +/- 0.9 to 5.5 +/- 2.2 micrograms/l (P < 0.001) during treatment and returned to basal values after stopping IGF-I administration.
CONCLUSIONS: Low procollagen levels in untreated Laron syndrome patients and their rise during replacement therapy with IGF-I provide evidence that IGF-I plays an important role in bone and soft connective tissue metabolism and that serum procollagen may serve as a marker to reflect some of the biochemical changes induced by IGF-I in connective tissue in the initial periods of treatment.
| Original language | English |
|---|---|
| Journal | Clinical Endocrinology |
| Volume | 45 |
| Issue number | 4 |
| Pages (from-to) | 423-9 |
| Number of pages | 7 |
| ISSN | 0300-0664 |
| Publication status | Published - Oct 1996 |
Keywords
- Adolescent
- Adult
- Biomarkers
- Body Composition
- Bone and Bones
- Child
- Child, Preschool
- Collagen
- Collagen Type I
- Connective Tissue
- Dwarfism
- Female
- Growth Hormone
- Humans
- Insulin-Like Growth Factor I
- Male
- Obesity
- Peptide Fragments
- Peptides
- Procollagen
- Recombinant Proteins
- Syndrome
- Clinical Trial
- Journal Article
