Objective: Discontinuation of growth hormone (GH) therapy on completion of linear growth may adversely affect bone mineral density (BMD) in young adults with childhood-onset GH-deficiency (GHD). In the present study, we analyzed the impact of GH treatment on bone in young adults with GHD.
Methods: BMD at the lumbar spine (L2-L4), total hip, and total body was measured at baseline and after 24 months in a cohort of young adults (18-25 years; n=160) with severe GHD treated with GH during childhood who were randomized to GH (n=109) or no treatment (n=51) in a multicenter, multinational, open-label study. GH starting doses (0.2 mg/day (males), 0.4 mg/day (females)) were increased after 1 month to 0.6 mg/day (males) and 0.9 mg/day (females) and then to 1.0 mg/day (males) and 1.4 mg/day (females) at 3 months for the remainder of the study.
Results: After 24 months, lumbar spine BMD had increased significantly more in GH-treated patients than in controls (6 vs 2%; estimated treatment difference; 3.5% (95% confidence interval, 1.52-5.51) P<0.001). GH also had a significant positive effect on total hip BMD (P=0.015). Total body BMD was unchanged from baseline (P=0.315).
Conclusions: In young adults treated for childhood-onset GHD, there is a beneficial effect of continued GH treatment on BMD in adult life. Twenty-four months of GH treatment in these young adults was associated with an estimated 3.5% greater increase in BMD of the lumbar spine compared with controls.