Adolescents with Prader-Willi syndrome who continued growth hormone therapy after they reached adult height did not maintain bone density, according to findings published in Clinical Endocrinology.
However, those with hypogonadism who received sex steroid replacement therapy had improved total body bone mineral density vs. those who did not — regardless of GH therapy or placebo.
Donze, MD, of the Dutch Research Foundation and the department of pediatrics, subdivision of endocrinology at Erasmus University Medical Center-Sophia Children’s Hospital in the Netherlands, and colleagues evaluated 27 young adults with Prader-Willi syndrome (PWS; 19 women; mean age, 17.2 years; mean BMD standard deviation score [SDS], 0.9) randomly assigned to 1 year of once-daily injections of GH 0.67 mg/m2 (Genotropin, Pfizer) or placebo, after which they crossed over to the alternative treatment for 1 year. During childhood, participants started GH at mean age 8.5 years and received the treatment for a mean of 8.7 years until attainment of adult height. Researchers sought to determine the effects of continued GH compared with placebo on BMD after attainment of adult height.
At 1 year, SDS for total body and lumbar spine BMD were not significantly deteriorated from baseline with GH or placebo. At 2 years, BMD of the total body SDS remained unchanged, whereas BMD of the lumbar spine SDS declined significantly from baseline regardless of treatment with GH or placebo.
Researchers also evaluated a subgroup of participants with hypogonadism to determine the effect on BMD of sex steroid replacement therapy in addition to GH; 11 (eight women) received sex steroid replacement, and 12 (eight women) did not. At baseline, total body and lumber spine BMD measurements were similar among all participants with hypogonadism. At 2 years, regardless of treatment with GH or placebo, participants not treated with sex steroid replacement therapy had slightly decreased SDS for total body and lumbar spine BMD, whereas those receiving sex steroids had significantly increased BMD of the total body SDS (from –1.1 to –0.7; P < .01).
“Our results suggest that GH is not able to prevent decline the decline in BMD SDS in hypogonadal young adults with PWS, unless it is combined with [sex steroid replacement therapy]. Close monitoring of BMD in adolescents and young adults with PWS is recommended and [sex steroid replacement therapy] should be considered in cases of hypogonadism and a declining BMD SDS,” the researchers wrote. – by Amber Cox
Disclosures: Donze reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.