Parathyroid gland function
Increase serum calcium concentration by increasing calcium pulled from bone and decreasing excretion at the kidney.
Excessive excretion of PTH by one or more PTH gland leading to hypercalcemia. Usually due to an adenoma.
Associated with chronic kidney failure & vitamin D deficiency. PTH glands are stimulated to produce more PTH hormone to make up for decreased serum calcium.
If PTH glands enlarge due to over-production of PTH associated with secondary hyperparathyroidism, they can start to produce too much PTH on their own.
Signs and symptoms
- "Bones, stones, abdominal groan & psychic moans with fatigue overtones."
- Bones - pain, arthralgia
- Stones - kidney
- Abdominal groans - stones, duodenal ulcer, pancreatitis
- Psychic moans - depression, apathy (indifference)
Serum calcium (corrected) = Ca + (4-albumin) x 0.8
- Calcimimetic drugs (for primary) - Sensipar
- Good for people with hypercalcemia - binds to Ca sensor in parathyroid & increases affinity for serum Ca, thereby decreasing PTH secretion (it thinks there's more calcium in blood)
Calcium & vitamin D treatment
- Don't restrict Ca - will stimulate PTH
- Vitamin D with multivitamin
- Serum calcium level - every 6 mos
- Serume creatinine conc. (check kidneys) - annually
- BMD - annually at all 3 sites.
- All other tests not recommended
Surgical treatment for hyperparathyroidism
- Calcium level > 1mg/dl over upper limit
- Creatinine clearance reduced to <60 ml/min
- BMD T-scor less than -2.5 at any site, with or without fragility fracture
- Age < 50
- Another thing to consider w/ surgery is whether they have renal stones.
- Order SESTEMIBI scan if considering surgery - will show which glands are abnormal.
- Can lead to hungry bone syndrome
Surveillance without surgery
- Serum calcium level annually
- BMD every 1-2 years (3 sites)
Good way to tell if surgery was successful when only going after 1 gland. PTH is cleared from body within 3 minutes or so, so surgeon can check PTH levels during surgery to decide whether another gland needs to be taken out. iPTH should decrease by more than 50% in successful cases.