Secondary Hyperparathyroidism

Excerpt

Parathyroid hormone (PTH) is secreted by parathyroid glands and plays a role in calcium and skeletal metabolism. Important triggers for PTH secretion are hypocalcemia and hyperphosphatemia. On the other hand, the secretion of PTH is reduced by 1,25 (OH)(2) vitamin D(3). Secondary hyperparathyroidism (SHPT) is an increased secretion of PTH due to parathyroid hyperplasia caused by triggers such as hypocalcemia, hyperphosphatemia, or decreased active vitamin D. The increased PTH secretion, in turn, causes increased calcium in the blood by acting on bones, intestines, and kidneys.

Prolonged SHPT is often associated with disturbances of bone turnover, as well as visceral and vascular calcifications, which are responsible for cardiovascular morbidity and mortality.

Despite improvements in medical treatment, surgical treatment of SHPT is often necessary, especially in refractory cases. Renal transplantation is a therapeutic alternative but is frequently followed by the persistence of hyperparathyroidism.