Which chemicals increase blood calcium?
PTH
Vitamin D
How do blood calcium levels increase?
Absorption from gut
Moves from bone to blood
Reabsorption from kidneys
How is calcium excreted?
Kidneys
Which gland regulates calcium concentration?
Parathyroid gland
Which receptors on parathyroid glands sense calcium concentration?
Calcium sensing receptors
How is Vitamin D obtained?
Diet (oily fish, red meat and eggs)
Sunlight
What is the mnemonic for hypercalcaemia symptoms?
Stones (renal stones)
Bones (osteoporosis)
Groans (abdominal pain)
Psychic moans (depression)
add on polydipsia and polyuria as well
What are the acute symptoms of hypercalcaemia?
Polydipsia
Polyuria
Confusion
What is seen in chronic hypercalcaemia?
Myopathy
Osteoporosis > Fragility fracture
Hypertension
Abdo pain - pancreatitis, ulcers, kidney stones
What is measured to diagnose hypercalcaemia itself?
Serum calcium
What are the two most common causes of hypercalcaemia?
Primary hyperparathyroidism
Malignancy
Which drugs cause hypercalcaemia?
Vit D - causes inc. calcium absorption, reabsorption and transfer from bones
Thiazide diuretics - increase calcium reabsorption from kidneys
Which granulomatous diseases can cause hypercalcaemia?
Sarcoidosis
TB
(High / low) bone turnover causes hypercalcaemia.
High bone turnover
so diseases like Paget’s
Which tests are done to diagnose hyperparathyroidism?
Raised serum calcium
Raised PTH (or inappropriately normal for Ca levels)
Increased urine calcium secretion
How does malignancy cause hypercalcaemia?
Bone destruction
PTHomas
Inflammatory factors activate osteoclasts
Which liver enzyme will be elevated in hypercalcaemia secondary to malignancy?
ALP
How is suspected malignancy investigated?
Imaging - X-ray, CT, MRI
Nuclear imaging - isotope bone scan
How is hypercalcaemia treated?
Fluid resuscitation if dehydrated
LOOP diuretics (thiazides cause hypercalcaemia)
Bisphosphonates to reduce osteoclast activity
If granulomatous disease, steroids
Which type of scan is used to view the activity of the thyroid and parathyroid together?
Sestamibi scan
What is the only definitive treatment for hyperparathyroidism?
Surgery
i.e parathyroidectomy
If surgery isn’t appropriate, how is hyperparathyroidism treated?
No treatment available
What are some complications of hyperparathyroidism?
Bone disease inc. osteoporosis BONES
Peptic ulcers GROANS
Renal stones STONES
Depression PSYCHIC MOANS
What is primary hyperparathyroidism?
Which PTH and Ca levels would you see?
Overactivity of parathyroids due to adenoma/carcinoma or hyperplasia
Raised PTH, raised Ca
Which genetic syndromes are associated with primary hyperparathyroidism?
MEN-1, MEN-2A
causing parathyroid tumours which secrete TSH, leading to hypercalcaemia
What is secondary hyperparathyroidism?
Which PTH and Ca levels would you see?
Physiological response to low calcium levels e.g in chronic kidney failure
Low Ca, raised PTH
What is tertiary hyperparathyroidism?
Which PTH and Ca levels would you see?
Autonomous parathyroids after years of secondary
Ca raised, PTH raised
Why must you check urinary calcium levels as well as blood calcium when diagnosing hypercalcaemia??
Hypercalcaemia w/ low urinary excretion of calcium indicates FAMILIAL HYPOCALCIURIC HYPERCALCAEMIA, a genetic condition
What is the problem in hypocalciuric hypercalcaemia?
Calcium sensing receptor on parathyroid gland has higher set point for calcium
So higher Ca conc. required before PTH is switched off
What are the symptoms of hypocalcaemia?
Paraesthesia
Muscle pain, tetany and weakness
What PTH level is seen in hypocalcaemia?
High PTH level
What are two physical signs of hypocalcaemia?
Chovstek’s sign - tapping on the parotid gland causes mouth to twitch
Trousseau’s sign - inflating BP cuff causes wrist and finger flexion
What is an ECG sign of hypocalcaemia?
Prolonged QT interval
What causes hypocalcaemia?
Hypoparathyroidism
Vitamin D deficiency (causing osteomalacia/Rickets)
Chronic renal failure
How is acute hypocalcaemia treated?
IV calcium
Which congenital syndrome causes hypoparathyroidism?
DiGeorge syndrome
invariably causes absent parathyroids
Deficiencies in which two chemicals can cause hypoparathyroidism?
Vitamin D
Magnesium (causing hypoparathyroidism > hypocalcaemia)
What usually causes hypoparathyroidism?
Destruction / removal of parathyroids
How is hypocalcaemia managed long-term?
Calcium, Vitamin D supplements
Which ion is required to release calcium from cells?
Magnesium
What name is given to hypocalcaemia in which PTH is high?
Pseudohypoparathyroidism
What causes pseudohypoparathyroidism?
Genetic mutation causing PTH resistance rather than failure to produce PTH
Which bone diseases are caused by Vitamin D deficiency?
Which bone diseases can be caused by (amongst other things) calcium and phosphate deficiency?
Rickets / Osteomalacia
Osteoporosis
What causes Vitamin D deficiency?
Lack of Vitamin D in diet
Malabsorption
Renal failure
Lack of sunlight
Chronic renal failure causes a ___ _ deficiency leading to which kind of hypoparathyroidism?
Vitamin D
secondary
Patients with osteomalacia / Rickets who are given Vitamin D supplements may not respond - why?
X-linked hypophosphataemia
