Objective Discontinuation of growth hormone therapy (rhGH) upon completion of linear growth may adversely affect bone mineral density (BMD) and bone mineral content (BMC) in adolescents with childhood-onset GH deficiency (CO-GHD) and predispose them to osteoporosis. In the present study, we analyzed the impact of non-weight-based low-dose somatropin withdrawal on bone accrual during this transition among CO-DGH patients who had been treated since childhood.
Methods Lumbar spine (LS) and whole-body (WB) BMD and BMC were measured at baseline and after 18 months in 54 adolescents (age: 16.8 ±1.6 years). They were retested and reclassified as GH sufficient (GS, n= 28) and GH insufficient. The last group were later randomized to use rhGH (GH+; n= 15) or no treatment (GH-, n= 11) in this single-center open-label study. The average dose of rhGH was 0.5 ± 0.18 mg/day.
Results When comparing the 3 groups, the GH group had a lower percentage change in LS BMD than the GS group (0.53 % ± 5.9 vs. 4.42 % ± 4.1, respectively, p < 0.04). However, in the analysis of the GH+ and GH- subgroups, the LS BMC percentage change was higher in the GH+ group (11.02% ± 10.12 vs. 2.05 % ± 10.31, respectively, p< 0.04).
Conclusions Non-weight-based low-dose somatropin withdrawal for 18 months limits bone accrual in LS of CO-DGH in transition. More studies on this therapeutic regimen are necessary to assess the long-term impact on peak bone mass in these younger populations.