Calcium part 2 Flashcards
Biochemistry in osteoporosis?
NORMAL
What bones are measured on a dexa scan?
Hip, spine and wrist
How is osteoporosis diagnosed?
DEXA scan
What is a T score?
Normal healthy young person
What is a Z score?
Compared to age-matched person
How is osteopenia defined?
T score of -1 to -2.5
What drugs can cause osteoporosis?
Prednisolone
What can cause rapid bone loss?
Sedentary, alcohol use, smoking, low BMI/poor nutrition, hyperprolactinaemia, thyrotoxicosis, Cushing’s disease, steroids, prolonged intercurrent illness
Treatment to prevent osteoporosis?
Vitamin D, bisphosphonate
What is the problem with oral bisphosphonates?
Irritate the stomach, must be taken on an empty stomach with plenty of water. If taken alongside calcium, will just be excreted out.
How often is zelendronate given?
Yearly
What is teriparatide?
PTH analogue/derivative
SERMS - example raloxifen - how does it affect bone?
Improves bone density, agonist on bone
Similar to tamoxifen
Normal calcium level?
2.2-2.6
Osteomalacia?
Same amount of bone but bone is not calcified (content is wrong)
Osteomalacia is caused by what?
Lack of vitamin D
Osteoporosis is caused by what?
Increasing age and sedentary lifestyle
Symptoms of high calcium?
Polydipsia/polyuria
Constipation
Neuro symptoms
In high calcium, what should the PTH be?
Suppressed
What is high calcium with suppressed PTH indicative of?
Malignancy
Most common cause of hypercalcaemia in hospital?
Metastatic cancer invading bone
What else could cause high calcium with suppressed PTH?
Sarcoidosis, vitamin D excess, thyrotoxicosis, milk alkali syndrome
High calcium with normal PTH?
Primary hyperparathyroidism
Commonest cause of hypercalcaemia in the community?
Primary hyperaparathyroidism
Parathryroid hyperplasia is associated with what?
MEN 1, 2A?
Which bone is affected first in primary hyperparathyroidism?
Wrist
Primary hyperparathyroidism signs?
Bones, stones, moans and groans
PTH bone disease, renal calculi, constipation, pancreatitis, confusion
Parathryroid adenoma is normally singular or multiple?
Singular
What is familial benign hypercalcaemia?
High PTH and calcium
Body can’t see this
Leave them alone! Caused by a gene mutation
How does malignancy cause hypercalcaemia?
- Humoural hypercalcaemia of malignancy (PTHrp)
- Bone metastasis (Local bone osteolysis)
3.Haematological malignancy (cytokines)
What is PTHrp?
Shouldn’t be expressed in adults. Can be expressed by cancer cells.
What cancers can secrete PTHrp?
Small cell lung cancer
How does sarcoidosis cause hypercalcaemia?
Non-renal production of 1 alpha hydroxylase
How does thryotoxicosis cause hypercalcaemia?
Causes bone resorption
How does hypoadrenalism cause hypercalcaemia?
Affects renal calcium transport
Which drugs can cause hypercalcaemia?
Thiazide diurectics (wee out less calcium)
How is hypercalcaemia treated?
0.9% saline !!!! (4L daily if they don’t have heart failure)
How to treat hypercalcaemia known to be caused by malignancy?
Bisphosphonates
When shouldn’t you give bisphosphonates?
If high calcium is caused by hyperparathyroidism
Signs of low calcium?
Tetany
Chvtoken’s sign - tap the facial nerve
Trousseau’s sign - Carpal spasm when BP cuff is put on
Can also cause hyperreflexia, convulsions and stridor
Treatment for hypocalcaemia?
IV calcium
How to check if low calcium is a true hypocalcaemia?
check albumin and get adjusted calcium level
Then - what’s the PTH?
Causes of hypocalcaemia?
Chronic kidney disease, post-parathyroidectomy, vitamin D deficiency, PTH resistance, DiGeorge syndrome, hypoparathyroidism
Thyroid operation can cause what?
Can cut out parathryoid, need to take calcitrol for life
What is paget’s disease
Thought to be a virus that causes increased bone turnover
Elevated ALP on biochemistry
Treatment’s for paget’s disease?
Bisphosphonates for pain
Signs of Paget’s disease?
Focal pain, warmth, deformity, fracture, SC compression, malignancy, cardiac failure
What is renal osteodystrophy?
Secondary hyperaparathyroidism + retention of aluminium from dialysis fluid
