Secondary hyperparathyroidism
| Secondary hyperparathyroidism | |
|---|---|
| Other names | SHPT |
 | |
| Thyroid and parathyroid. | |
| Specialty | Endocrinology |
Secondary hyperparathyroidism is the medical condition of excessive secretion of parathyroid hormone (PTH) by the parathyroid glands in response to hypocalcemia (low blood calcium levels), with resultant hyperplasia of these glands. This disorder is primarily seen in patients with chronic kidney failure. It is sometimes abbreviated "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 the blood, immune system, and neurological system.[citation needed]
Cause
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 kidney disease[2] or defective calcium receptors on the surface of parathyroid glands.[3]
Treatment
If the underlying cause of the hypocalcemia can be addressed, the hyperparathyroidism will resolve. In people with chronic
Extended Release Calcifediol was recently approved by the FDA as a treatment for secondary hyperparathyroidism (SHPT) in adults with stage 3 or 4 chronic kidney disease (CKD) and low vitamin D blood levels (25-hydroxyvitamin D less than 30 ng/mL). It can help treat SHPT by increasing Vitamin D levels and lowering parathyroid hormone or PTH. It is not indicated for people with stage 5 CKD or on dialysis.[citation needed]
In the treatment of secondary hyperparathyroidism due to chronic kidney disease on dialysis calcimimetics do not appear to affect the risk of early death.[5] It does decrease the need for a parathyroidectomy but caused more issues with low blood calcium levels and vomiting.[5]
Most people with hyperparathyroidism secondary to chronic kidney disease will improve after renal transplantation, but many will continue to have a degree of residual hyperparathyroidism (tertiary hyperparathyroidism) post-transplant with associated risk of bone loss.[6]
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. In contrast with secondary hyperparathyroidism, tertiary hyperparathyroidism is associated with hypercalcemia rather than hypocalcemia.[citation needed]