Hyperparathyoidism Flashcards
Primary HPT:
What is the main cause?
PTH adenoma or 4-gland hyperplasia
Primary HPT:
It causes hypercalcaemia!
Presentation - most asymptomatic:
- What neurological symptoms can it cause and why? - 2
- What psychological illness could it also cause?
- Why do they feel tired, weak and muscle and bone pain?
Hypercalcemia can interfere with how your brain works, resulting in confusion, lethargy and fatigue. It can also cause depression.
Confusion
Coma
Depression
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In most cases, the excess calcium in your blood was leached from your bones, which weakens them. This can cause bone pain and muscle weakness.
Primary HPT:
Presentation - most asymptomatic:
- Why do they polyuria, polydipsia and subsequent dehydration?
The calcium-sensing receptors (CaSRs) found in the kidney play a major role in volume status due to their expression in the thick ascending loop (TAL) of Henle and the collecting duct. Interestingly, hypercalcemia activates the CaSR in the medullary portion of TAL, causing inhibition of the same cotransporter (Na-K-2Cl) inhibited by furosemide and other loop diuretics (2-4)! Hypercalcemia also inhibits vasopressin action ( therefore urine concentration) by activating CaSR in the collecting duct (5). Lastly, inhibition of Na+-K+ ATPase in the proximal convoluted tubule may further contribute to natriuresis and subsequent polyuria.
Thus, hypercalcemia may lead to polyuria by interfering with the absorption of sodium as well as inhibiting the action of vasopressin.
Primary HPT:
Presentation - most asymptomatic:
- Why do they get abdo pain and N&V?
- Why do they get constipation?
- Why do they get gastric/duodenal ulcers?
- What GI organ may become inflamed? - rare
Increased gastric acid secretion often accompanies hypercalcemia. Anorexia, nausea, and vomiting are made worse by increased gastric residual volume.
Constipation is worse due to dehydration associated with hypercalcemia.
Due to increased gastric acid secretion
Pancreas - leading to pancreatitis
Primary HPT:
Presentation - most asymptomatic:
- What does increased bone resorption cause? - 2
- What does increased bone resorption increase the risk of?
- What may increased calcium levels leave in the kidneys?
- What does high calcium levels also cause an increase in?
Pain
Osteoporosis/osteopenia (a less severe form of osteoporosis)
Fractures
Kidney stones
Acute hypercalcemic hypertension is caused by an increase in vascular resistance mediated via the direct effect of calcium on vascular smooth muscle as well as the indirect effect of calcium-induced hypercatecholaminemia.
Primary HPT:
What is a good phrase to remember all the symptoms?
‘Stones, bones, groans, and psychiatric moans’
Primary HPT:
Investigations:
- Bloods - what is measured? - 2
- What do you expect phosphate levels to be like?
- What liver enzyme is increased with increased bone resorption?
- What imaging is used to look at bone density?
Calcium
PTH
Phosphate should be low - remember phosphate and calcium move in the opposite directions
ALP
DEXA scan - Dual-energy X-ray absorptiometry
Primary HPT:
Treatment:
What can be done to prevent the formation of stones?
What should be avoided in the diet to prevent their levels from going up? - 2
When is the excision of the adenoma or 4 hyperplastic glands needed?
Complications of excision:
- What nerve could be damaged?
- What could surgery cause biochemically?
Increased fluid intake
Avoid high calcium and vit d intake
High serum or urinary calcium bone disease Osteoporosis Renal calculi Reduced renal function Under age 50
Recurrent laryngeal nerve - hoarse voice
Hypoparahytodism - leading to symptomatic hypocalcaemia
Secondary HPT:
What causes it?
What are the calcium and phosphate levels?
Treatment - correcting cause is the main Rx.
- Why are phosphate binders prescribed?
- What is Cinacalcet?
Low calcium intake - PTH rises to compensate
Low calcium
High phosphate
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Phosphate binders are medications used to reduce the absorption of dietary phosphate; they are taken along with meals and snacks. They are frequently used in people with chronic kidney failure (CKF), who are less able to excrete phosphate, resulting in elevated serum phosphate.
Cinacalcet decreases levels of parathyroid hormone (PTH), calcium, and phosphorous in the body. Cinacalcet is used to treat hyperparathyroidism (overactive functioning of the parathyroid glands) in people who are on long-term dialysis for kidney disease.
Tertiary HPT:
Bloods:
- High calcium
- High phosphate
This usually happens after secondary hyperparathyroidism. Why?
What organ is failing which this usually seen in?
Glands being to act autonomously (does what it wants) having undergone a hyperplastic or adenomatous change.
This cause hypercalcaemia from increased secretion of PTH unlimited by feedback control.
Chronic renal failure
What liver enzyme is raised in hypercalcaemia?
ALP - Alkaline phosphate
