Endocrine Abstracts (2013) 32 P84 | DOI: 10.1530/endoabs.32.P84

Effects of treatment for acromegaly on bone mineral density: is pegvisomant protective on lumbar BMD?

Giulia Brigante1,2, Daniele Santi1,2, Chiara Diazzi1,2, Sara De Vincentis1,2, Giulia Ferrannini1,2, Bruno Madeo1,2, Cesare Carani1,2, Manuela Simoni1,2 & Vincenzo Rochira1,2

1Chair and Unit of Endocrinology and Metabolism, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; 2Integrated Department of Medicine, Endocrinology and Metabolism, Geriatrics, Azienda USL of Modena, NOCSAE of Baggiovara, Modena, Italy.

Background: GH–IGF1 status is important for bone health. Acromegaly affects bone status, but less is known on the role of treatments for acromegaly on bone mineral density (BMD). Pegvisomant (Peg) is effective in treating acromegaly by reducing IGF1. As serum GH is not influenced by Peg, it is not known if residual, direct GH effects on bone (not IGF1 mediated) are preserved during treatment.

Methods: To evaluate the effects of Peg on BMD, we compared five patients treated with Peg (alone or in combination) to six patients treated with somatostatin analogues (SA) and to seven patients surgically cured, not under medical therapy. All the patients had normal serum IGF1. BMD was measured by DEXA (Hologic-QDR-2000 densitometer, Inc., Waltham, MA). A t-score of ≤1 and ≤2.5 at lumbar spine (L1–L4) and at femoral neck was used for diagnosis of osteopenia and osteoporosis, respectively.

Results: Mean age of subjects (seven males and nine females) was 60.7±9.8 years. At lumbar spine, 40% of Peg-patients, 33.3% of SA-patients, and 60% of not-treated patients had osteopenia; none of the Peg-patients, and 16.7% of SA-patients, and none of not-treated patients were osteoporotic. Considering the femoral neck, 60% of Peg-patients, 33% of SA-patients, and 60% of not-treated patients had osteopenia; 20% of Peg-patients and none of the other two groups were osteoporotic.

Conclusions: The percentage of osteoporotic/osteopenic acromegalic patients seems to be lower than that reported in literature. Peg seems to protect bone at lumbar spine, but this protective effect does not seem to be exerted at femoral level where, indeed, patients treated with Peg present lower densitometric values. Patients surgically cured, not under medical therapy, have higher rate of lumbar osteopenia. No data are available on bone quality, a parameter that is usually altered in acromegaly.