Endocrine Abstracts

Background: RhGH treatment in adults with childhood onset growth hormone deficiency (COGHD) affect bone metabolism over time according to gender and age. A long-term study of bone mass density (BMD) in young-middle age hypopituitary patients with COGHD may better highlight possible benefits of therapy and improve clinical follow up.

Methods: We enrolled 40 adults (age range during follow-up: 16.8–36 years, F: 38%) with COGHD with at least 20 years of clinical follow-up. The following data were collected at baseline and during the follow-up: anthropometric parameters,hormonal data, IGF-1 values, lumbar spine and femoral neck BMD derived from DEXA. Based on IGF-1 levels patients were divided into two groups: patients with continuous sufficient IGF-1 levels (at least 60% of IGF-1 values within the normal age and gender range) and patients with discontinuous IGF-1 levels (< 60% of IGF-1 values within the normal range).

Results: At lumbar spine,at baseline 47.5%of patients were osteopenic and 17.5% of patients were osteoporotic, these percentages did not differ during the follow-up. At femoral neck, 44.7% of patients were osteopenic and 2.6% were osteoporotic at study start and after 15 years of follow-up the percentage of osteopenic patients increased significantly while the others remained stable. Regarding BMD values, at lumbar spine there was a progressive increase of BMD up to 10 years of follow-up with a following reduction and a return to baseline after 20 years (BMD g/cm²: baseline 0.923 ± 0.12, 10 years 0.991 ± 0.13 P baseline vs 10 years < 0.05, 20 years 0.924 ± 0.15). At femoral neck there was no changes in BMD values up to 10 years, followed by a BMD deterioration below basal values after 20 years (BMD g/cm²: baseline 0.797 ± 0.14, 15 years 0.704 ± 0.12 P vs baseline < 0.05, 20 years 0.706 ± 014 P vs baseline < 0.05). Men had higher BMD than women at both sites. Patients with continuously sufficient IGF-1 levels had greater lumbar spine BMD levels compared to those with discontinuous IGF-1 levels (BMD IGF-1 in range vs IGF-1 below range: 10 years 1.009 ± 0.14 vs 0.903 ± 0.12 P < 0.05, 15 years 0.948 ± 0.11 vs 0.861 ± 0.13 P < 0.05, 20 years 0.975 ± 0.12 vs 0.867 ± 0.13 P < 0.05), no differences were found in femoral neck BMD.

Conclusion: Our data supports the need for a punctual monitoring of bone metabolism and IGF-1 levels during prolonged rhGH therapy in GHD. Tostudy the long-term effect of GH replacement therapy on risk fracture in a rare condition such as GH deficiency, a multicenter study would be needed.