ESPE Abstracts

Objective: Re-testing of childhood-onset GHD needs discontinuation of GH treatment at near-adult height. We recently reported significant changes of body composition as a consequence of severe GHD during this time period.

Aim: Does a 6 month interruption of GH treatment decrease bone quality significantly in patients with severe GHD of adolescence?

Patients and Methods: In 90 patients with childhood onset GHD treatment was stopped when patients reached near-adult height (HV <2cm/yr). After three months patients were retested with arginine-GHRH-test. After six months GH treatment was restarted in patients with a GH maximum <16 ng/ml and low IGF-1 (n=17, 4 females, mean age 16.3 yr). At stop of GH treatment and at 6 months off GH we performed a pQCT scan (XCT 2000 Stratec corp. Germany) of the non-dominant forearm at the 4 and 65% measure points. Measures of patients with severe GHD of adolescence were compared to that of patients with transient GHD of childhood (n=73, 15 females, mean age 17.1 yr,).

Results: In severe GHD of adolescence the trabecular density decreased from 214 to 202mg/cm³ (P<0.01); in transient GHD a similar decrease from 220 to 214 was observed (P<0.05).The trabecular density remained within the reference range in both groups.

In both groups increases were observed with respect to cortical density from 1077 to 1099 mg/cm³ (P<0.01) versus 1060 to 1079 mg/cm³ (P<0.001), with respect to strength strain index from 306 to 310 mm³ (n.s.) vs. 302 to 312 mm³ (P<0.05), and with respect to total bone area from 145 to146 mm² (n.s.) vs. 153 to 155 mm² (n.s.). The changes of bone density and geometry were comparable.

Conclusion: Only trabecular density decreased significantly during 6 months off GH in all patients, independent of their GH status. Therefore we conclude that discontinuation of GH treatment for confirmation of the diagnosis does not harm the bone.