Growth hormone and hypophosphatemic rickets.

Area of Science:

• Pediatric Endocrinology
• Metabolic Bone Diseases
• Genetics

Background:

• X-linked hypophosphatemic rickets (XLHR) is a rare genetic disorder characterized by impaired phosphate reabsorption.
• Conventional treatment with oral phosphate and calcitriol often fails to normalize serum phosphate and achieve normal adult height.

Purpose of the Study:

• To review the available evidence from clinical trials on the efficacy and safety of growth hormone (GH) treatment in patients with XLHR.
• To evaluate the impact of GH on growth velocity, phosphate levels, and adult height in XLHR.

Main Methods:

• Systematic review of seven clinical trials involving growth hormone (GH) therapy in X-linked hypophosphatemic rickets (XLHR).
• Analysis of patient response based on age, growth velocity, serum phosphate levels, and final adult height.

Main Results:

• Growth hormone (GH) treatment, when added to conventional therapy, demonstrated increased growth velocity in XLHR patients.
• Younger patients showed a better response to GH compared to older individuals.
• Potential concerns include disproportionate trunk growth, and the clinical benefit of GH-induced phosphate increases is uncertain.

Conclusions:

• Growth hormone (GH) appears safe for treating X-linked hypophosphatemic rickets (XLHR), but its long-term benefits, particularly on adult height, require further investigation.
• The independent effect of GH and its impact on phosphate metabolism in XLHR warrant additional study.