Secondary hyperparathyroidism 3704508 222205544 2008-06-28T02:11:08Z 75.13.47.115 /* Causes */ {{Infobox_Disease | Name = Secondary hyperparathyroidism | Image = Illu thyroid parathyroid.jpg | Caption = Thyroid and parathyroid. | DiseasesDB = 6301 | ICD10 = {{ICD10|E|21|1|e|20}} | ICD9 = {{ICD9|252.02}}, {{ICD9|588.81}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = D006962 | }} '''Secondary hyperparathyroidism''' refers to the excessive secretion of [[parathyroid hormone]] (PTH) by the [[parathyroid gland]]s in response to [[hypocalcemia]] (low [[blood]] [[calcium]] levels) and associated hypertrophy of the glands. This disorder is especially seen in patients with chronic renal failure. It is often--although not consistently--abbreviated as SHPT in medical literature. ==Signs and Symptoms== Bone and joint pain are common, as are limb deformities. The elevated PTH has also pleiotropic effects on blood, immune system and neurological system. ==Diagnosis== The PTH is elevated due to decreased levels of calcium or 1,25-dihydroxy-vitamin D3. It is usually seen in cases of chronic renal disease or defective calcium receptors on the surface of parathyroid glands. ==Causes== [[Chronic renal failure]] is the most common cause of secondary hyperparathyroidism. Failing [[kidneys]] do not convert enough [[vitamin D]] to its active form, and they do not adequately excrete [[phosphorus]]. When this happens, insoluble [[calcium phosphate]] forms in the body and removes calcium from the circulation. Both processes leads to hypocalcemia and hence secondary hyperparathyroidism. Secondary hyperparathyroidism can also result from malabsorption (chronic pancreatitis, small bowel disease) in that the fat soluble vitamin D can not get reabsorbed. This leads to hypocalcemia and a subsequent increase in parathyroid hormone secretion in an attempt to increase the serum calcium levels. ==Treatment== If the underlying cause of the hypocalcemia can be addressed, the hyperparathyroidism will resolve. In patients with chronic renal failure, older treatments consists of dietary restriction of phosphorus, supplements with the active form of [[vitamin D]] (Paricalcitol), and [[phosphate binders]]. In recent years, a newer class of medications, calcimimetics [[cinacalcet]], have achieved amazing response rates and has reduced the number of patients who eventually require surgery. Some of these patients may also see resolution of their sHPT following kidney transplantation. ==Prognosis== If left untreated, the disease will progress to [[tertiary hyperparathyroidism]], where correction of the underlying cause will not stop excess PTH secretion, i.e. parathyroid gland hypertrophy becomes irreversible. ==See also== * [[Primary hyperparathyroidism]] * [[Tertiary hyperparathyroidism]] {{Endocrine pathology}} [[Category:Parathyroid disorders]] [[pl:Wtórna nadczynność przytarczyc]] ==External links== * [http://www.crescentcme.org '''CRESCENTcme.org''' - The '''C'''ritical '''R'''ol'''E''' of '''S'''erum '''C'''alcium: An '''E'''ducational '''N'''etwork for Secondary Hyperpara'''T'''hyroidism]