Endocrinology Flashcards
What are the causes of a false positive ARR
Beta Blockers
NSAIDs
Alpha agonists (central) - clonidine
What are the causes of a false negative ARR
Spironolactone
ACE and ARBs
Other Diuretics
SSRI
Which form of insulin is bound to albumin?
Detemir
Which cells do bisphophonates act?
Osteoclasts
How does prednisone cause osteoporosis
Suppression of osteoblast proliferation.
What response would expect to see with Desmopressin after water deprivation in central DI?
Dramatic response to DDAVP With osmolality of >600
What response would expect to see with Desmopressin after water deprivation in nephrogenic DI
Poor response (<50% increase) in urine osmolality.
What response would expect to see with Desmopressin after water deprivation in psychogenic polydipsia
No response (<10% increase in urine osmolality)
What is the treatment of lithium induced nephrogenic DI?
Low sodium diet
Amiloride
Indomethacin
Desmopressin (if not able to have indomethacin)
What is the treatment of central DI?
Low solute diet
Desmopressin
Thiazide diuretics
What is the treatment of nephrogenic DI?
Low sodium low protein diet
Thiazide diuretics
Characteristic findings in MEN1?
Pituitary Adenomas
Parathyroid hyperplasia
Pancreatic neuroendocrine tumours
What is commonly found on gastroscope in patients with Zollinger Ellison syndrome?
Single sub centimetre duodenal ulcer (75%)
How do you diagnose MEN1?
Clinical - 2 or more primary MEN1 tumour types
Genetic - Germline mutation in someone without clinical diagnosis
How do you investigate a high IGF-1?
Oral glucose tolerance test with growth hormone levels.
What is the single best test for acromegaly?
Serum IGF-1
How do you interpret an oral glucose tolerance test when diagnosing acromegaly?
Levels of growth hormone 2 hours post administration.
GH >1ng/ml is diagnostic of acromegaly.
What is the treatment of acromegaly?
- Trans-sphenoidal surgery
- Long acting somatostatin analogue (if not for surgery or not controlled)
- Addition of pegvisomant if not controlled
Mechanism of pegvisomant?
Growth hormone receptor antagonist.
Mechanism of cabergoline?
Dopamine receptor agonist
What is the most common genetic cause of MODY3?
HNF1a
What is the mechanism of pasireotide?
Somatostatin receptor 5 agonist used in acromegaly.
Osteogenesis imperfecta is a disorder of what?
Type 1 collagen
What mutation would you most often find in a patient with an autonomous thyroid module?
Activating TSH receptor mutation
What is the pathophys of Graves’ disease?
Thyroid stimulating immunoglobulin production
Thyrotropin receptor antibodies
Mechanism of carbimazole?
Inhibition of iodine oxidation
What do you measure to monitor for recurrent medullary thyroid cancer?
Calcitonin
What is the treatment of a macroprolactinoma?
- Dopamine agonist therapy
2. Surgery if does not respond
What is the management of acromegaly in a patient who is a candidate for surgery?
- Surgery
- Long acting somatostatin analogue (octreotide)
- Add on dopamine agonist
- Replace DA with pegvisomant
- Radiation or repeat surgery
What is the most common autoimmune disease associated with type 1 DM?
Autoimmune thyroiditis
What are the major antibodies associated with Hashimoto’s thyroiditis ?
Thyroid peroxidase
Thyroglobulin
What is the treatment of painless thyroiditis?
Hyperthyroid phase - beta blockade
Hypothyroid phase - thyroxine
What is the cell that PTH primarily acts on in bone?
Osteoblast
What effect does amiodarone have on T4 and T3?
Inhibits peripheral conversion of T4 to T3
What are the most likely diagnoses with a low TSH, a high T3 and a normal T4?
Graves’ disease
Thyroid adenoma
What are the most likely diagnoses with a low TSH, a high T4 and a normal T3?
Amiodarone induced
Thyroxine ingestion
Non thyroidal illness
What are the sonographic features for a thyroid nodule which necessitate FNA?
Subcapsular location
Extra thyroidal extension
Large lymph nodes
Solid and >1cm
