Donze SH, et al. - In this two-year, randomized, double-blind, placebo-controlled, crossover GH study, the researchers examined the effects of growth hormone (GH) vs placebo, and besides the effects of sex steroid replacement therapy (SSRT), on bone mineral density (BMD) in GH-treated young adults with Prader-Willi syndrome (PWS) who had attained adult height (AH). They discovered that 1 year of placebo after attainment of AH did not deteriorate BMD SDS in young adults with PWS compared to GH treatment. Unless it was combined with SSRT, GH was not able to prevent the decline in BMD SDS in hypogonadal young adults with PWS.