October 1991

Growth Hormone Therapy in Hypophosphatemic Rickets

Author Affiliations

From the Departments of Pediatrics, Stanford (Calif) University (Drs Wilson and Rosenfeld); University of Colorado Health Science Center, Denver (Dr Lee); The City of Hope Hospital, Duarte, Calif (Dr Morris); Baystate Medical Center, Tufts University of School of Medicine, Springfield, Mass (Dr Reiter); Cornell University Medical College, New York, NY (Dr Gertner); the Department of Medicine, Stanford University (Dr Marcus); and Peptide Section, Endocrine Sciences, Calabasas Hills, Calif (Dr Quarmby). Dr Lee is now with the Department of Pediatrics, Baylor College of Medicine, Houston, Tex.

Am J Dis Child. 1991;145(10):1165-1170. doi:10.1001/archpedi.1991.02160100097031

• The effects of growth hormone therapy on the biochemical measures of bone metabolism were studied in 11 children aged 3.5 to 17 years who had familial hypophosphatemic rickets; five were male. Subjects were maintained on a regimen of stable doses of conventional therapy (calcitriol and phosphate). Subjects were studied at baseline receiving conventional therapy and during three sequential treatment periods: no therapy (4 weeks), growth hormone only (0.05 mg/kg per day for 4 weeks), and conventional therapy plus growth hormone (2 weeks). The nine youngest subjects were continued on a regimen of triple therapy for an additional 24 weeks. Serum phosphate averaged 0.93±0.13 mmol/L (mean±SD) at entry and decreased when the subjects were not receiving any therapy. During the 4 weeks of growth hormone only treatment, phosphate rose in all 11 subjects (0.70±0.08 mmol/L to 0.83±0.08 mmol/L). With triple therapy, phosphate remained higher than with no therapy. Calcitriol, osteocalcin, and parathyroid hormone increased as the subjects received growth hormone alone. Insulinlike growth factor I z scores rose significantly in response to growth hormone therapy alone. All nine subjects receiving 6 months of triple therapy increased their growth rate z scores. Exogenous growth hormone therapy may be useful in familial hypophosphatemic rickets.

(AJDC. 1991;145:1165-1170)