Parathyroid Disease (2)

Question 1

Which cells produce PTH?

How does PTH affect Calcium and Phosphate?

How does Vit D affect Calcium and Phosphate?

Answer 1

➊ Chief cells

➋ Increases Ca and decreases Ph:
• Increases bone osteoclast activity, which releases Ca and Ph
• Increases gut Ca reabsorption
• Increases kidney Ca (and reduces Ph) reabsorption
• Activates Vit D

➌ Increases absorption of Ca and Ph in the gut

Question 2

Hyperparathyroidism:
What occurs in Primary hyperparathyroidism?
→ What does it lead to?
→ How does it present?

What occurs in Secondary hyperparathyroidism?
→ What are its causes?

What occurs in Tertiary hyperparathyroidism?
→ What causes it?

How is it managed?

Answer 2

➊ Excess PTH due to a tumour
→ Hypercalcaemia
→ Stones, Bones, Groans and Psychiatric Moans

N.B. Parathyroid adenoma is most common cause (85%) of primary hyperparathyroidism.

➋ Release of PTH in response to low calcium because of kidney, liver, or bowel disease.
→ Vit D deficiency, CKD, Ca malabsorption

➌ Prolonged secondary hyperparathyroidism, which leads to gland hyperplasia and excessive PTH relaease even after correction of hypocalcaemia
→ Long-standing kidney disease

➍ Surgical removal of gland(s)

Question 3

Hypoparathyroidism:
What occurs in Primary hypoparathyroidism?
→ What does it lead to?
→ How does it present?

What causes Secondary hypoparathyroidism?

What occurs in Pseudohypoparathyroidism?
→ How does it present?

How is it managed?

Answer 3

➊ Autoimmune gland failure
→ Hypocalcaemia
→ SPASMODIC

➋ Surgery, Radiation, Hypomagnesaemia (Mg needed for PTH secretion)

➌ Failure of target response to normal levels of PTH
→ Short stature and fingers, Hypocalcaemia

➍ Calcium and Vit D supplementation