Abstract 497 Poster Session I, Saturday, 5/1 (poster 289)

Introduction: The body composition phenotype seen in Prader-Willi syndrome (PWS) resembles states of growth hormone (GH) deficiency. We previously reported improved body composition, and increased fat utilization, growth, and strength and agility in children with PWS treated with GH (1mg/m2/day) in a randomized controlled study. Resting energy expenditure (REE) was measured by indirect calorimetry, body composition and bone mineral density (BMD) were analyzed by DEXA, and tests of physical strength and agility (sit-ups, weight lifts, running speed and coordination) were performed prior to, and after 12 months of therapy. A critical question after the initial 12 months, was whether effects of GH would persist or wane with more prolonged therapy.

Results: In 35 patients who have completed 24 months of GH therapy, body composition changes (decreased fat mass, increased lean mass) and growth acceleration were preserved, BMD continued to increase, respiratory quotient (RQ) decreased further (indicating increased fat utilization), and tests of muscle strength and agility continued to improve (table).

Table 1 No caption available.
Full size table

Conclusion: The response of children with PWS to GH therapy (significant reduction in body fat, increase in lean body mass, continued growth acceleration, and improved physical strength and agility, as well as an increase in REE with reduction in RQ) is sustained at 24 months. Further, BMD increased, and tests of timed agility improved during the additional 12 months of therapy. In children with PWS, GH therapy has beneficial effects on body composition, energy expenditure, bone mineral density, growth, and physical strength and agility which is sustained during 24 months of treatment.

Finding from Genentech Foundation for Growth and Development, Eli Lilly and Co., and NIH M01 RR0318613S1. Dr. Allen is a member of the advisory board to the National Cooperative Growth Study, funded by Genentech.