Secondary Hyperparathyroidism (SHPT) Flashcards
How is bone disease and cardiovascular illness affected by kidney failure?
Both are known as one of the silent diseases of dialysis patients along with diabetes and hypertension.
A patient can have an elevated parathyroid hormone (PTH) level for a long time before clinical consequences become apparent.
One of consequences of an elevated parathyroid hormone (PTH) is bone disease which over time may result in calcium deposits in the blood vessels.
Heart attack and stroke may result along with damage to other organ systems such as the nervous system, pancreas, skeletal muscles, lungs and skin with prolonged elevations of PTH.
What are osteoclasts?
Cells that break down calcium and phosphorus from the bones when PTH is secreted.
Elevated PTH increases osteoclastic activity resulting in excessive release of calcium and phosphorus from the bones into the blood leading to hypercalcemia and hyperphosphatemia.
The loss of calcium and phosphorus from the bones leads to osteodystrophies or bone diseases such as brittle bones, increased risk of fractures and osteoporosis.
How is bone disease treated?
Since kidney disease destroys nearly all of the body’s ability to make active vitamin D, the main treatment for SHPT is vitamin D hormone replacement therapy.
Advancement in the prevention and treatment of SHPT has taken place in the last 5 years with the development of vitamin D2 analogs.
Vitamin D2 analogs have been shown to have fewer side effects such as hypercalcemia, than previously used medications and closely mimics the normal physiologic metabolism of vitamin D.
An example of a vitamin D2 analog is paricalcitol (Zemplar®). This medication is available in capsule form for peritoneal patients.
What are symptoms of high phosphorus?
Itching, bone pain and numbness and tingling are due to alterations in phosphorus and calcium.
If phosphorus levels are not controlled through diet and the use of phosphate binders, itching may result. Itching can also result from iron deficiency and anemia?
A high PTH and calcium/phosphorus imbalance may cause a hypo-response to ESA’s (erythropoietic stimulating agents like EPO) and iron sucrose injection, USP (Venofer®).
