Bone mineral density in young adults with Prader-Willi syndrome: A randomized, placebo-controlled, crossover GH trial.

Context: The prevalence of osteoporosis is increased in adults with Prader-Willi syndrome (PWS). In children with PWS, growth hormone (GH) treatment has beneficial effects on bone mineral density (BMD). BMD might deteriorate after cessation of GH at adult height (AH), while continuing GH might maintain BMD.
Objective: To investigate the effects of GH vs placebo, and furthermore the effects of sex steroid replacement therapy (SSRT), on BMD in GH-treated young adults with PWS who had attained AH.
Design: Two-year, randomized, double-blind, placebo-controlled, crossover GH study.
Patients: Twenty-seven young adults with PWS were stratified for gender and BMI and then randomly and blindly assigned to receive GH (0.67 mg/m ² /day) or placebo for 1 year, after which they crossed over to the alternative treatment for another year.
Measurements: Bone mineral density of the total body (BMD _TB ) and lumbar spine (BMD _LS ) SDS were measured by dual-energy x-ray absorptiometry.
Results: At AH, BMD _TB SDS was significantly lower compared to healthy peers (P < .01), while BMAD _LS SDS was similar. Both BMD _TB SDS and BMAD _LS SDS were similar during 1 year of GH vs 1 year of placebo. In hypogonadal young adults without SSRT, BMD _TB SDS and BMAD _LS SDS decreased during the 2-year study (P = .11 and P = .01), regardless of GH or placebo, while BMD _TB SDS increased in those with SSRT (P < .01).
Conclusions: Compared to GH treatment, 1 year of placebo after attainment of AH does not deteriorate BMD SDS in young adults with PWS. In addition, our data suggest that GH is not able to prevent the decline in BMD SDS in hypogonadal young adults with PWS, unless it is combined with SSRT.
(© 2018 John Wiley & Sons Ltd.)