Effect of growth hormone treatment on calcium kinetics in patients with osteogenesis Imperfecta Type III and IV

• Published in: Bone (New York, N.Y.) N.Y.), 1999-10, Vol.25 (4), p.501-505
• Main Authors: Vieira, N.E, Marini, J.C, Hopkins, E, Abrams, S.A, Yergey, A.L
• Format: Article
• Language: English
• Subjects: Adolescent; Biological and medical sciences; Bone; Calcification, Physiologic - drug effects; Calcium; Calcium - blood; Calcium - urine; Child; Child, Preschool; Children; Female; Growth Hormone - pharmacology; Growth Hormone - therapeutic use; Hormones. Endocrine system; Humans; Male; Medical sciences; Metabolism; Osteogenesis imperfecta (OI); Osteogenesis Imperfecta - drug therapy; Osteogenesis Imperfecta - metabolism; Osteogenesis Imperfecta - physiopathology; Pharmacology. Drug treatments; Stable isotopes
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/S8756-3282(99)00186-6

Using a dual stable isotope technique, the effect of growth hormone (GH) on whole body calcium (Ca) metabolism was studied in children (ages 5–14 years) with type III (n = 9) and IV (n = 8) osteogenesis imperfecta. Each subject was studied twice: at baseline and following a GH (0.1–0.2 U/kg per day) treatment period of 1–1.5 years. Subjects were given 42Ca intravenously and 44Ca orally. The sera and urine 42Ca and 44Ca isotopic enrichments were followed over 7 days using thermal ionization mass spectrometry. The S aam program was used to fit a three-compartment model to the tracer data. No significant differences were observed between: (1) children with type III and IV disease; or (2) baseline studies of boys and girls within each disease type. However, GH treatment significantly increased: (1) the exchangeable calcium pool (EP) in type III patients (2086 vs. 4422 mg/day, p = 0.02); and (2) the parameter associated with bone calcium accretion in type IV patients (Vo +: 973 vs. 1560 mg/day, p = 0.03) with boys responding with a significantly greater increase than girls (p = 0.008). Although not statistically significant, a trend toward an increase in Vo + in type III patients and in EP in type IV was observed following treatment. Our observations imply that more Ca was available for bone mineralization following GH treatment in these subjects.