calcium disorders

Question 1

what is the calcium sensing receptor?

Answer 1

it is a G protein coupled receptor that plays an essential part in regulation of extracelluar calcium homeostasis

Question 2

what are the classic symptoms of hypercalcaemia?

Answer 2

Bones
Stones
Abdominal Groans
Psychic Moans

Question 3

what are the acute symptoms of hypercalaemia?

Answer 3

Thirst
Dehydration
Confusion
Polyuria

Question 4

what are the chronic symptoms of hypercalcaemia?

Answer 4

Myopathy
Fractures
Osteopaenia
Depression
Hypertension
Pancreatitis
DU
Renal calculi

Question 5

what is the most common cause of hyprcalcaemia?

Answer 5

primary hyperthyroidism
then malignancy

Question 6

what are less common causes of hypercalcaemia?

Answer 6

Drugs: Vit D, thiazides
Granulomatous Disease eg Sarcoid, TB
Familial Hypocalciuric Hypercalcaemia
High turnover: bedridden, thyrotoxic, Pagets
Others
Tertiary hyperparathyroidism

Question 7

what is the first line investigation for hypercalcaemia?

Answer 7

parathyroid hormone level (PTH)

Question 8

what are the criteria for a diagnosis of primary hyperparathyroidism?

Answer 8

Raised serum calcium
Raised serum PTH (or inappropriately normal)
Increased urine calcium excretion
Ensure Vitamin D replete

Question 9

what occurs in malignancy to lead to hypercalcaemia?

Answer 9

Metastatic Bone destruction
PTHrp from solid tumours
Osteoclast activating factors

Question 10

how is hypercalcaemia managed?

Answer 10

Fluids- rehydrate with 0.9% saline 4-6L in 24hours

Consider loop diuretics once rehydrated- avoid thiazides

Bisphosphonates- single dose will lower Ca over 2-3d, maximum effect at 1 week

Steroids occasionally used e.g Pred 40-60mg/day for sarcoidosis

Question 11

does chemo reduce calcium in malignant disease?

Answer 11

yes

Question 12

how is hypercalcaemia treated in sarcoidosis?

Answer 12

prednisolone

Question 13

what is the main managements of primary hyperparathyroidism?

Answer 13

surgery (though not always required)
cinacalcet: Calcium Mimetic
Can be useful if need treatment, but
unfit for surgery
Approved for tertiary
hyperparathyroidism and
parathyroid carcinoma

Question 14

what is primary hyperparathyroidism?

Answer 14

Primary overactivity of Parathyroid gland i.e adenoma

Question 15

what are the biochemical markers of primary hyperparathyroidism?

Answer 15

high calcium
high PTH

Question 16

what is secondary hyperparathyroidism?

Answer 16

Physiological response to low calcium or vit D

Question 17

what are the biochemical markers of secondary hyperparathyroidism?

Answer 17

low calcium
high PTH

Question 18

what is tertiary hyperparathyroidism?

Answer 18

Parathyroid becomes autonomous after many years of overactivity e.g renal failure

Question 19

what are the biochemical markers of tertiary hyperparathyroidism?

Answer 19

high calcium
high PTH

Question 20

what is chovsteks sign?

Answer 20

tapping over the facial nerve

Question 21

what is trousseau sign?

Answer 21

carpopedal spasm

Question 22

what are the causes of hypoparathyroidism?

Answer 22

Congenital absence (DiGeorge syndrome)
Destruction (surgery, radiotherapy, malign)
Autoimmune
Hypomagnesaemia
Idiopathic

Question 23

what is the long term management of hypoparathyroidism?

Answer 23

Calcium supplement : > 1-2 g per day
Vitamin D Tablets:
1 alphacalcidol 0.5-1 mcg
(sometimes more)
Depot injection:
Cholecalciferol 300,000 units 6
monthly

Question 24

what are the causes of hypomagnasaemia?

Answer 24

Alcohol
Drugs
Thiazide
PPI
GI illness
Pancreatitis
Malabsorption

Question 25

what is pseudohypoparathyroidism?

Answer 25

GENETIC Defect (dysfunction of G protein (Gs alpha subunit)- Gene= GNAS 1
Low calcium, but PTH concentrations are elevated
Due to PTH resistance

Question 26

what are the symptoms of pseudohypoparathyroidism?

Answer 26

Bone abnormalities (McCune Albright)
Obesity
Subcutanous calcification
Learning Disability
Brachdactyly (4th metacarpal)

Question 27

what is pseudo pseudohypoparathyroidism?

Answer 27

Albright’s Herditary Osteodystrophy But…No alteration in PTH action and thus Normal calcium