Primary hyperparathyroidism causes hypercalcemia (elevated blood calcium levels) through the excessive secretion of parathyroid hormone (PTH), usually by an adenoma (benign tumors) of the parathyroid glands. Its incidence is approximately 42 per 100,000 people. It is almost exactly three times as common in women as men.
* Hyperparathyrodism * Peptic ulcers * Pancreatitis * Renal calculi * Enlarged parathyroid gland
The most common cause of primary hyperparathyroidism is a sporadic, single parathyroid adenoma resulting from a clonal mutation (~97%). Less common are hyperplasia of all parathyroid glands (~2.5%), parathyroid carcinoma (malignant tumor), and adenomas in more than one gland (together ~0.5%). Primary hyperparathyroidism is also a feature of several familial endocrine disorders: Multiple endocrine neoplasia type 1 and type 2A (MEN type 1 and MEN type 2A), and familial hyperparathyroidism.
The diagnosis of primary hyperparathyroidism is made by blood tests. Serum calcium levels are elevated. The serum chloride phosphate ratio is 33 or more in most patients with primary hyperparathyroidism. However, thiazide medications have been reported to causes ratios above 33. Urinary cAMP is occasionally measured; this is generally elevated.
Surgery to remove the enlarged gland (or glands) is the main treatment for the disorder and cures it in 95 percent of operations. Calcimimetics are a new class of drug that turns off secretion of PTH. They have been approved by the Food and Drug Administration for the treatment of hyperparathyroidism secondary to kidney failure with dialysis, and primary hyperparathyroidism caused by parathyroid cancer. They have not been approved for primary hyperparathyroidism, but some physicians have begun prescribing calcimimetics for some patients with this condition. Patients can discuss this class of drug in more detail with their physicians.