[Glucocorticoid and Bone. Pathogenesis of glucocorticoid-induced osteoporosis]

Glucocorticoid (GC) is widely used to treat a variety of inflammatory and allergic diseases and about one million people in Japan are known to take oral GC. GC causes a number of adverse effects and among them osteoporosis and degenerative bone fracture are major complications of GC therapy. GC induces apoptosis of osteoblasts and osteocytes and prolongs lifespan of osteoclast, resulting in low bone mass and microarchitectural deterioration of bone tissue, which leads to severe osteoporosis, increased bone fragility and susceptibility to bone fracture. Although GC-induced osteoporosis is the most common iatrogenic osteoporosis, few physicians fully manage it. Physicians who prescribe GC have to manage patients according to guidelines on the management and treatment of GC-induced osteoporosis, because recent multiple evidences strongly indicate that certain medication such as bisphosphonates is effective for treatment and prophylaxis of GC-induced osteoporosis.