Bone Mineral Density during 3 years of Growth Hormone in previously GH-treated Young Adults with PWS.

OBJECTIVE In children with Prader-Willi syndrome (PWS), growth hormone (GH) treatment has positive effects on bone mineral density (BMD). Two one-year studies did not show a difference between GH or placebo on BMD in young adults with PWS. However, there are no studies investigating BMD during longer-term GH treatment in young adults with PWS. DESIGN Open-label, prospective study in 43 young adults with PWS. METHODS BMD of the total body (BMDTBSDS) and lumbar spine (BMADLSSDS) measured by DXA. RESULTS In the total group, estimated mean (95% CI) BMDTB remained similar during 3 years of GH, being -0.76 (-1.11 to -0.41) SDS at start and -0.90 (-1.27 to -0.54) SDS after 3 years (p=0.11), as did BMADLS, being -0.36 (-0.72 to 0.01) SDS and -0.46 (-0.77 to -0.16) SDS resp. (p=0.16). In men, there was a significant decrease in BMDTBSDS during 3 years of GH, while BMADLSSDS remained similar. In women, both BMDTBSDS and BMADLSSDS remained similar. BMDTBSDS was associated with female sex, lean body mass and age. The majority of patients received sex steroid replacement therapy (SSRT). CONCLUSIONS During 3 years of combined GH and SSRT treatment, BMD remained stable in the normal range in young adults with PWS. However, men showed a decline in BMDTBSDS, probably due to insufficient SSRT. We recommend to continue GH treatment in young adults with PWS and to start SSRT during adolescence unless puberty progresses normally.