Bone mineral density and effects of growth hormone treatment in prepubertal children with Prader-Willi syndrome: a randomized controlled trial.

Author(s): de Lind van Wijngaarden RF, Festen DA, Otten BJ, van Mil EG, Rotteveel J, Odink RJ, van Leeuwen M, Haring DA, Bocca G, Mieke Houdijk EC, Hokken-Koelega AC

Affiliation(s): Dutch Growth Research Foundation, Erasmus University Medical Center/Sophia Children's Hospital, 3016 AH Rotterdam, The Netherlands. r.delindvanwijngaarden@erasmusmc.nl

Publication date & source: 2009-10, J Clin Endocrinol Metab., 94(10):3763-71. Epub 2009 Jul 21.

Publication type: Research Support, Non-U.S. Gov't

BACKGROUND: Bone mineral density (BMD) is unknown in children with Prader-Willi syndrome (PWS), but is decreased in adults with PWS. In patients with GH deficiency, BMD increases during GH treatment. OBJECTIVES: The aim of the study was to evaluate BMD in children with PWS and to study the effects of GH treatment. DESIGN: We conducted a randomized controlled GH trial. Forty-six prepubertal children were randomized into either a GH-treated group (1.0 mg/m(2) . d) or a control group for 2 yr. At start, 6, 12, and 24 months of study, total body and lumbar spine BMD were measured by dual-energy x-ray absorptiometry, and lumbar spine bone mineral apparent density (BMAD) was calculated. RESULTS: Baseline total body and lumbar spine BMD sd score (SDS) were normal [mean (sd), -0.2 SDS (1.1) and -0.4 SDS (1.2), respectively]. BMADSDS, which corrects for short stature, was also normal [mean (sd), 0.40 SDS (1.1)]. Total body BMDSDS decreased during the first 6 months of GH (P < 0.0001), but increased during the second year of treatment. After 24 months of study, total body and lumbar spine BMDSDS, and the BMADSDS did not significantly differ between GH-treated children and randomized controls (P = 0.30, P = 0.44, and P = 0.47, respectively). Results were similar when corrected for body mass index SDS. Repeated measurements analysis showed a significant positive association between IGF-I SDS and total body and lumbar spine BMDSDS, but not with BMADSDS. CONCLUSIONS: Our results show that prepubertal children with PWS have a normal BMD. GH treatment had no effect on BMD, except for a temporary decrease of total body BMDSDS in the first 6 months.