Disorders of Calcium Homeostasis

Question 1

what rhyme is used for the symptoms of hypercalcaemia

Answer 1

stones
bones
abdominal moans
psychic groans

Question 2

clinical manifestations of hypercalcaemia

Answer 2

muscle weakness
anorexia
nausea
mood change
depression
impaired water concentration in kidneys
renal stone formation
bone disease
abdominal pain
ECG changes - shortened QT interval, AF

Question 3

what ECG changes are associated with hypercalcaemia

Answer 3

shortened QT interval
AF

Question 4

causes of factitious hypercalcaemia

Answer 4

venous stasis (e.g. due to tourniqué)
dehydration
IV albumin

Question 5

what is factitious hypercalcaemia

Answer 5

high Ca due to high plasma albumin
non-pathological

Question 6

what is the difference between primary, secondary and tertairy hyperparathyroidism

Answer 6

1 - autonomous and innappropriate overproduction of PTH leading to hypercalcaemia
2 - appropriate increase in PTH in response to hypocalcaemia
3 - where a secondary overactive gland becomes overactive

Question 7

cell appearance in biopsy in normal parathyroid compared to abnormal

Answer 7

normal - heterogenous cells
abnormal - homogenous cells

Question 8

what features could be seen in xrays of someone with hyperparathyoridism

Answer 8

kidney stones
osteopenia

Question 9

what will Ca and PTH levels be in primary hyperparasthyroidism

Answer 9

raised Ca
inappropriately raised PTH (should be low if Ca is high)

Question 10

serum phosphate and bicarbonate levels in primary hyperparathyroidism

Answer 10

low due to increased renal excretion

Question 11

what can be used for more difficult diagnoses of primary hyperparathyroidism

Answer 11

parathyroid imaging scan - using radioisotope

Question 12

treatment of primary hyperparathyroidism

Answer 12

acutely rehydration and drugs
surgery to remove tumour
unless mild or can’t tolerate surgery - then drugs and monitoring of Ca and PTH levels

Question 13

drugs for hypercalcaemia

Answer 13

bisphosphonates
furosemide
calcitonin (short term)
glucocorticoids

Question 14

most common cause of hypercalcaemia in hospitalised patients

Answer 14

malignant disease

Question 15

why is malignant disease a common cause of hypercalcaemia

Answer 15

endocrine factors secreted by malignant cells act on the bone
metastatic tumour deposits in bone locally which stimulates bone resorption via osteoclast activation

Question 16

most common type of cancer to cause hypercalcaemia

Answer 16

lung
breast
multiple myeloma
(more likely to metastasise to bone)

Question 17

what endocrine factors are involved in malignant hypercalcaemia

Answer 17

solid tumours may secrete PTH-related peptide which is similar in structure and function to PTH
some tumours synthesise calcitriol

Question 18

clinical manifestations of hypercalcaemia of malignancy

Answer 18

abundance of plasma cells in biopsy
pepperpot skull due to bone resorption
weak bones which break easily

Question 19

Ca, PTH, phosphate and alkaline phosphatase levels in malignant hypercalcaemia

Answer 19

Ca high
PTH low
phosphate high
alkaline phosphatase high

Question 20

treatment of malignant hypercalcaemia

Answer 20

rehydration
drugs to lower calcium (e.g. bisphosphonates)
treat cancer

Question 21

causes of hypercalcaemia

Answer 21

primary hyperparathyroidism
cancer
granulomatous disease (e.g. sarcoidosis)
exogenous vitamin D excess
FHH
drugs (e.g. lithium, thiazide diuretics)
endocrine disease (e.g. thyrotoxicosis, Addison’s)
immobilisation

Question 22

what part of the body is usually affected in sarcoidosis

Answer 22

lungs (90%)
skin (10%)

Question 23

Ca and PTH levels in sarcoidosis

Answer 23

Ca - high
PTH - normal

Question 24

how does sarcoidosis cause high Ca

Answer 24

vitamin D is hydroxylated in the granulomas
so more Ca absorbed

Question 25

what does FHH stand for

Answer 25

familial hypocalciuric hypercalcaemia

Question 26

what is FHH

Answer 26

Ca sensor on PT glands less sensitive to Ca suppression so altered set point for PTH and Ca interaction PTH levels high normal or slightly high high plasma Ca low urine Ca

Question 27

clinical manifestations of hypocalcaemia

Answer 27

numbness parastheasia anxiety fatigue muscle cramps carpo-pedal spasm bronchial or laryngeal spasm seizures personality change mental confusion psychoneurosis impaired intellectual ability ECG changes (long QT interval) eye problems

Question 28

what characteristic do hypocalcemia symptoms have

Answer 28

due to increased muscular excitability

Question 29

what is Chvostek's sign and what is it a sign of

Answer 29

contraction of eye mouth or nose when tapping along facial nerve hypocalcaemia

Question 30

what is Trousseau's sign and what is it a sign of

Answer 30

anterior lower arm muscles contracting when the brachial artery is occluded for 3 minutes hypocalcaemia

Question 31

what is factitious hypocalcaemia

Answer 31

low calcium as a consequence of low plasma albumin

Question 32

causes of facitious hypocalcaemia

Answer 32

malnutrition/malabsorption (protein deficiency in diet) liver disease (reduced liver synthesis) nephrotic syndrome (albumin lost in urine)

Question 33

causes of hypocalcaemia

Answer 33

vitamin D deficient/lack of vitamin action - lack of sunlight - inadequate dietary source - malabsorption - CKD

Question 34

why does low vit D cause bone disease

Answer 34

low vit D → low Ca → PTH rise → increased bone resorption also bone that is laid down is not adequately calcified

Question 35

Vit D, Ca, PTH, phosphate and ALP levels in vit D deficiency

Answer 35

vit D low Ca low PTH high phosphate low ALP raised

Question 36

rickets is called what in adults

Answer 36

osteomalacia

Question 37

causes of hypoparathyroidism

Answer 37

surgical damage/removal suppressed secretion (e.g. low Mg or maternal hypercalcaemia) inherited developmental parathyroid problems genetic disorders

Question 38

Ca and PTH in hypoparathyroidism

Answer 38

low Ca inappropriately low PTH

Question 39

treatment of hypocalcaemia

Answer 39

IV/oral calcium IM or oral vit D close monitoring of plasma calcium

Question 40

are there changes to Ca in osteoporosis

Answer 40

no

Question 41

how is osteoporosis investigated

Answer 41

DEXA scan

Question 42

histology of bone in osteoporosis vs osteomalacia

Answer 42

osteoporosis - normal formation but just less of it osteomalacia - uncalcified osteiod (bone matrix)