[Parathyroid hormone in osteoporosis].

Continuous parathyroid hormone secretion caused by primary hyperparathyroidism contributes to osteoporosis. Laboratory tests, in particular the intact PTH assay, make the diagnosis of hyperparathyroidism certain. In hyperparathyroidism, the bone damage primarily affects the cortical bone, especially the proximal one-third of the radius and to a lesser degree the upper femur; the lumbar spine is affected more rarely. Intermittent administration of parathyroid hormone stimulates bone formation and is useful in treating osteoporosis. Subcutaneous injections once daily administration of PTH stimulates bone formation on the surface of trabecular and cortical bone, by preferential stimulation of osteoblastic more than osteoclastic activity.