[Glucocorticoid-induced osteoporosis--mechanisms and preventions].

It has been well known that patients with Cushing's syndrome have frequently osteoporosis or bone loss due to excess endogenous glucocorticoids and also osteopenia or osteoporosis is commonly observed in patients with long-term glucocorticoid therapy. In this paper, the mechanisms involved in bone loss in Cushing's syndrome and glucocorticoid-induced osteoporosis were demonstrated. In the patients with Cushing's syndrome, excess endogenous glucocorticoids increase bone resorption and decrease bone formation and also act to depress intestinal calcium absorption and increase urinary calcium excretion, leading to compensatory stimulation of parathyroid hormone secretion. Then, parathyroid hormone stimulates bone resorption. Thus, secondary osteoporosis is commonly observed due to excess glucocorticoid. Finally, preventions and managements for glucocorticoid-induced osteoporosis were discussed.