Hyperparathyroidism

Question 1

Where is PTH produced in parathyroid glands and what are its main functions?

Answer 1

Chief cells

Increase osteoclasts activity
Increase Ca2+ absorption in gut
Increase Ca2+ absorption in kidneys
Increase Vit D activity= acts to increase GIT absorption of Ca2+

Question 2

What causes of symptoms associated with parathyroidism and how might someone present?

Answer 2

Hypercalcaemia

Renal stones
Painful bones
Abdominal groans i.e. constipation, N+V
Psychiatric moans i.e. fatigue, depression, psychosis

Question 3

There are 3 forms of hyperparathyroidism based on the cause. How can you differentiate between them?

Answer 3

Primary hyperparathyroidism

• uncontrolled parathyroid production by parathyroid adenoma
• High PTH + high calcium

Secondary

• vitamin D deficiency or CKD cause low calcium levels which leads to chronic stimulation of parathyroid gland to increase PTH= leads to HYPERPLASIA
• High PTH + low/normal calcium

Tertiary

• when hyerplastic parathyroid glands become autonomous= continue to make increased PTH despite cause of initial hypocalcaemia has been resolved= leads to hypercalcaemia
• High PTH + high calcium

Question 4

How would you diagnose primary hyperparathyroidism?

Answer 4

High calcium 
High PTH
Normal or concomitantly low vitamin D 
Increased urinary calcium excretion (sometimes) 
USS parathyroids for adenoma 
Parathyroid subtraction scanning

Question 5

How would you treat primary hyperparathyroidism?

Answer 5

Cinacalcet
-drugs acts on calcium-sensing receptors and acts to lower calcium and PTH
I.e. not treatment but can be used whilst awaiting surgery
Removal of parathyroid glands= only effective treatment