Endocrine Flashcards
(35 cards)
What autoantibodies should you test for in immune mediated type 1 DM?
- glutamic acid decarboxylase
- tyrosine phosphatase IA-2
in patients taking an ACEi or Angiotensin receptor blocker, what is a simple initial test that can rule out mineralocorticoid excess?
- plasma renin activity measurement
> a non suppressed renin level rules out primary aldosteronism/ mineralocorticoid excess
thyroid nodule: what initial test to send for?
TSH
- low TSH -> should ix with thyroid scintigraphy
- normal/high TSH -> US
Indications for fine needle aspiration biopsy of subcentimeter thyroid nodules?
- symptomatic
- pathologic lymphadenopathy
- extra thyroidal extension
- history of childhood radiation exposure
- familiar thyroid cancer syndrome
When should subclinical hyperthyroidism be treated?
TSH <0.1mU/L + cardiac risk factors, heart disease, high risk for osteoporosis or symptoms
how to adjust levothyroxine dosing in pregnant women with preexisting hypothyroidism?
increase the dose empirically by 30%
what ix to do for primary/secondary amenorrhoea after ruling out pregnancy?
- FSH
- TSH, T4
- Prolactin
Patients with PCOS should be screened for…?
- prediabetes/ DM
- hypercholesterolaemia
- obesity
- HTN
- obstructive sleep apnoea
how to diagnose male hypogonadism?
two low 8AM fasting serum total testosterone measurements
Should you give testosterone therapy in men planning for fertility?
no
- it impairs spermatogenesis
what is the calcium-creatinine clearance ratio in Familial hypocalciuric hypercalcaemia?
calcium creatinine clearance ratio of <0.01
treatment of Paget’s disease?
bisphosphonates
- iv zoledronic acid
what is a preferred 2nd line anti-diabetic drug after metformin in patients with established atherosclerotic CV disease or multiple risk factors e.g. HLD, obesity?
GLP1 receptor agonist (e.g. dulaglutide) or SGLTi (dapagliflozin)
incidentally discovered adrenal mass, what must you test for?
test for hypercortisolism
- even in the absence of typical symptoms
incidentally discovered adrenal mass: when do you also screen for pheochromocytoma?
if unenhanced CT attenuation >10 Hounsfield units, even in the absence of HTN
incidentally discovered adrenal mass: when do you also screen for hyperaldosteronism?
if there is also HTN or hypoK
how to follow up an incidentally discovered adrenal mass, asymptomatic patient with no evidence of mild autonomous cortisol excess and benign imaging phenotype?
repeat imaging at 12 months
hyperandrogenism + markedly elevated dehydroepiandrosterone dulfate (DHEA) levels?
usually adrenal source
- given that adrenal glands are the major source of DHEAS
(recommend to do CT Abdo when serum DHEAS >700μg/dL (19.0 μmol/L))
what labs to monitor in a transgender male taking testosterone masculinising therapy?
Hb
- testosterone can cause erythrocytosis
- recommend to monitor 3 monthly for 1st year then annually
what are some common conditions that cause upregulated conversion of 25 hydroxy vitamin D to 1-25dihydroxy Vit D with resultant hyperCa?
granulomatous tissue
- fungal infection, TB, sarcoid, lymphoma
what is the next ix to send after diagnosing someone with Cushing’s syndrome?
ie. positive low dose dexamethasone suppression test, high 24h urine free cortisol measurement, high late-night salivary cortisol measurement
ACTH
- to see if pt has ACTH dependent or independent Cushing’s syndrome
In ACTH - independent Cushing’s syndrome ie. ACTH suppressed, what is the next ix to organize?
CT abdo to image the adrenals or MRI
- to look for cortisol-secreting adrenal adenomas and rarely, carcinomas
In ACTH dependent Cushing’s syndrome, what ix would you do next?
MRI pituitary to look for pituitary tumour secreting ACTH
In ACTH dependent Cushing’s syndrome without a pituitary tumour visualised on MRI, what test can help to differentiate between an ectopic source of ACTH and a pituitary source?
High dose 8mg dexamethasone suppression test
- if pituitary source, responds to the negative feedback and suppressed the 8am cortisol by >50%
