| Theme | Evidence-based strategies for secondary hyperparathyroidism | |
|---|---|---|
| Title | When should we ask for parathyroidectomy to the surgeon in the management of secondary hyperparathyroidism? | |
| Publish Date | 2004/07 | |
| Author | Masanori Tokumoto | The Kidny Care Unit, Kyushu University Hospital |
| Author | Masatomo Taniguchi | The Kidny Care Unit, Kyushu University Hospital |
| Author | Hideki Uirakata | The Kidny Care Unit, Kyushu University Hospital |
| [ Summary ] | The severe form of secondary hyperparathyroidism (2ndry HPT) is characterized by continuous over-secretion of PTH, high turn-over bone disease, osteitis fibrosa. Parathyroid gland hyperplasia changes the diffuse to nodular, and finally to a single encapsulated nodular gland. As the parathyroid gland grows, 2ndry HPT becomes resistant to medical treatment, such as dietary phosphorus restriction, phosphate binders, and administration of active vitamin D. The negative-feedback regulation of PTH secretion with both extracellular calcium ion and active vitamin D failed to operate even with vitamin D pulse therapy. Hyperplastic parathyroid glands are often detected with ultrasonography, and glands over 0.5 cm3 in size usually indicate nodular hyperplasia, which is also confirmed in surgically-resected glands. Immunohistochemical studies clearly demonstrated the down-regulation of both vitamin D receptors and calcium sensing receptors in nodular hyperplastic glands. In this context, surgical parathyroidectomy is strongly recommended, when resistance to conservative treatment is apparent and several glands over 0.5 cm3 are recognized. The accelerated progression of severe cardiovascular calcification is another feature of 2ndry HPT, probably contributing to cardiovascular morbidity and mortality, leading causes of death in ESRD patients. Inhibition of cardiovascular events might be added to the list of future therapeutic targes for 2ndry HPT treatment. |
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