Changes in bone mineral density after discontinuation and early reinstitution of growth hormone (GH) in patients with childhood-onset GH deficiency.

We measured bone mass density (BMD) in 28 childhood-onset adult GHD patients (20 MPHD, 8 IGHD) treated with hGH until final height. Twelve were re-treated with hGH (0.06 U/kg/day three times per week) for 16-24 months and eight of them followed for up to 5 years. Age at start of the study was 23.6 +/- 5.7 years (mean +/- SD) and the interval since the first hGH treatment was 5.8 +/- 4.4 years Baseline BMD was 82% of young normal healthy subjects. Patients < 20 years had a lower BMD than those > 20 years (75 vs 87%;P = 0.004). In the 12 patients re-treated with GH, BMD was 5.3% above baseline at 6 months after treatment was stopped (P< 0.002), and remained so for 3.5 years in eight patients who completed follow-up. In conclusion, increases in BMD occur after cessation of growth, but continuation of hGH treatment after final height achievement may prevent the late osteopenia of patients with childhood-onset GHD.