Growth hormone therapy and fracture risk in the growth hormone-deficient adult

Adults with childhood-onset growth hormone deficiency (GHD) and younger adu lts with adult-onset GHD have a reduced bone mineral content (BMC). Recent trials with prolonged GH replacement therapy have demonstrated increased BM C in such patients. GH treatment in animals increases the amount of bone and the total strength while the density (BMC per unit volume) and the quality of the bone is not increased. A sensitive non-invasive parameter for the detection of effects of GH on bone in clinical studies is therefore to use the BMC from dual-en ergy X-ray absorption (DEXA) analysis. Bone density is strongly related to fracture risk in women. A number of oth er risk factors for fractures can be identified in adult GHD patients which , collectively, might explain the increased fracture frequency observed in these patients. The increase in BMC in response to long-term GH replacement therapy is prom ising. Whether more prolonged treatment will result in a normalization of t he bone mass and reduced fracture frequency remains to be established.