endocrinology Flashcards
precocious puberty - age definitions?
boys < 9, girls <8
central precocious puberty - what is it?
early maturation of the hypothalamic-pituitary-gonad axis
peripheral precocious puberty - what is it?
excess sex hormone (androgen) production from gonads, adrenals, or exogenous source
classic congenital adrenal hyperplasia - what is the defect - and what does it cause?
21-hydroxylase completely deficient (leads to salt wasting or virilization due to glucocorticoid or mineralicorticoid deficiencies)
nonclassic CAH - what is the defect?
21-hydroxylase reduced, therefore NO salt wasting. Signs of precocious puberty after infancy.
nonclassic CAH - symptoms?
hyperfunctioning endocrine syndrome
cafe-au-lait spots
fibrous dysplasia
early signs of puberty
drugs that increase thyroid binding globulin (therefore need higher dose of synthroid)?
tamoxifen
estrogen
raloxifene
methadone, heroin
drugs that reduce thyroid binding globulin (therefore need lower dose synthroid)?
androgens
danazol
anabolic steroids
glucocorticoids
patients with thyroid nodule and low TSH - next study?
radionucleotide uptake scan
patients with thyroid nodule and normal/high TSH - next study?
FNA
MEN Type I - features?
DIAMOND
- pituitary tumors
- hyperparathyroidism
- enteropancreatic tumors
what is ASCVD risk level to start statin?
> 7.5% @ 10 years
who should start a statin?
- 40-75 w/DM
- ASCVD risk >7.5% @ 10 years
- LDL >190
- ACS
- stable angina
- arterial revasc (stent, CABG)
- stroke, TIA, PVD
sick euthyroid - what is pathophys?
impaired conversion of T4 –> T3
what about sick people impairs conversion of T4 to T3?
- high endogenous cortisol
- inflammatory cytokines (TNF)
- starvation
- certain meds (amio, glucocorticoids)
subclinical hyperthyroid - clinical characteristics?
- suppressed TSH
- normal thyroid hormone levels
- +/- hyperthyroid symptoms
subclinical hyperthyroid - causes?
- exogenous thyroid hormone
- graves dz
- nodular thyroid dz
subclinical hyperthyroid - indications for tx?
- TSH persistently <0.1
- TSH 0.1-0.5 AND 1 of:
- – age >65
- – heart dz
- – osteoporosis
- – nodular thyroid dz
subclinical hypothyroidism - what is it?
- increased TSH
- normal T4
subclinical hypothyroidism - when to tx?
- TSH > 10
- TSH < 10 but high AND pt has anti-TPO Ab
- TSH < 10 but high AND pt has one of following:
- – goiter
- – symptoms
- – pregnancy
- – ovulatory dysfunction
- – hypercholesterolemia
why is serum T3 Unhelpful in hypothyroidism?
T4 –> T3 coversion is regulated by TSH, therefore in hypothyroidism, pts have increased TSH and therefore increased conversion of T4 –> T3
maternal changes to thyroid hormones in 1st trimester? (TSH, T4, FT4)
TSH - decreased
T4 - increased
FT4 - same/mild increase
which 2 hormones in pregnancy affect TSH/T4?
Estrogen = stimulated production of thyroxine-binding globulin = increased bound thyroid hormone, so increased production
- hCG = directly stimulates TSH receptors to make more thyroid hormone and suppresses pituitary signals for TSH release
which antithyroid drug should be used in pregnancy?
- PTY in 1st trimester
- methimazole in 2nd and 3rd
chronic autoimmune thyroiditis - what is the other name?
Hashimoto thyroiditis
Hashimoto thyroiditis (chronic autoimmune thyroiditis) - clinical features?
- hypothyroid symptoms
- diffuse goiter
treatment for subacute thyroiditis?
NSAID + BB
what is definitive tx in Graves disease?
radioiodine thyroid ablation
acromegaly suspected - which tests do you send?
- GH suppression test s/p glucose load (nonsuppression in acromegaly)
- serum IGF1 levels
patients w/T1DM are predisposed to what conditions?
- thyroid dysfunction
- adrenal failure
- primary hyogonadism
- atrophic gastritis
- celiac disease
causes of hypercalcemia with low PTH?
- malignancy
- vit D or A toxicity
- granulomatous dz
- drug-induced (thiazides)
- milk-alkali syndrome
- thyrotoxicosis
- immobilization
causes of hypercalcemia with normal/high PTH?
- primary (or tertiary) hyperparathyroidism
- familial hypocalciuric hypercalcemia
- lithium
in pregnancy, free thyroid and total thyroid hormone is corrected up to a factor of what?
1.5
hashimoto’s thyroiditis - what does TSH do?
GO UP
thyroid lymphoma - risk factor?
preexisting Hashimotos thyroiditis
follicular thyroid cancer - presentation?
palpable thyroid nodule
medullary thyroid cancer - assoc w/what syndrome?
multiple endocrine neoplasm
how treat pt w/hypoparathyroidism?
vitamin D (calciferol) or 1,25-vitD (calcitriol) but 1,25 more expensive and normal vit D works
what does PTH do?
- converts 25-OHvitD to 1, 25-OHvitD
- increases renal calcium reABSORPTION
what do in hypopara pt w/high Ca+ in urine, low Ca+ in blood?
add thiazide diuretic
how do SGLT-2 inhibitors work?
lower blood glucose by reducing reabsorption of glucose in the kidney which leads to low insulin-to-glucagon ratio
what is euglycmic ketoacidosis?
associated with SGLT-2 inhibitior use,
name an SGLT-2 inhibitor?
canaglifloin
women w/GDM should be tested with which test how long after birth?
- glucose tolerance test
- 6-12 weeks
primary hyperparathyroid - caused by what?
- parathyroid adenoma (most common)
- hyperplasia
- carcinoma
what puts pts @ risk for primary hyperparathyroidism?
MEN 1 & 2a
primary hyperparathyroidism - ab abnormalities?
- hypercalcemia
- high or inappropriately normal PTH
- high 24-hr urinary calcium excretion
parathyroidectomy in pts w/primary hyperparathyroid - indications?
- age < 50
- symptomatic hypercalcemia
- osteoporosis (T < -2.5, fragility fracture)
- nephrolithiasis/calcinosis
- high risk of complications: calcium > 1mg/dl above normal, urinary calcium excretion >400 mg/day
in person w/adrenal insufficiency and hypoT - what do you need to be careful of in treatment?
dont give levothyroxine before addressing the adrenal insufficiency
when do you measure reverse T3?
in hospiitalized pt to ditinguish euthyroid sick syndrome from central hypothyroidism
what happens to reverse T3 in sick euthyroid?
it is elevated
if you diagnose someone w/central hypoT, what else should you do?
- workup for other pituitary hormones- pituitary MRI
hormonal abnormalities in PCOS?
- high testosterone
- high estrogen
- LH/FSH imbalance
why do pts w/PCOS have infertility?
anovulation
SIADH associated w/which lugn cancer/
small cell
SIADH - treatment?
1 - fluid restriction
2 - may need salt tabs
3 - loop diuretics WITH hypertonic saline or salt tabs
4 - demeclocycline or lithium (blunts response of collecting tubule cells to ADH)
primary hyperaldo - how diagnose?
- plasma renin low
- aldo inapprop high
autosomal dominant polycystic kidney disease these pts are @ higher risk for what intraacranial abnormality?
berry aneurysm
raloxifene - what is it?
selective estrogen modulator - stimulates estrogen on bone cells, but ANTAGONIZES other estrogen-responsive tissues
familial hypocalcuric hypercalcemia - how treat?
no treatment needed
RET proto-oncogene - most common cause of what?
MEN types 2A and 2B
how distinguish familial hypocalcuric hypercalcemia from hypereparathyroid?
in FHH = low calcium urine excretion
in hyperparathyroid = high urine calcium excretion
thyroid effects of amiodarone
- decreased T4–> T3 conversion
- inhibition of thyroid hormone synthesis
- amiodarone induced thyrotoxicosis 2/2 increased thyroid hormone synthesis or destructive thyroiditis
how treat amio induced TFT abnormalities?
you dont - give it time
most common cause of primary hyperpara?
parathyroid adenoma
second line agent for pts who have failed bisphosphonate therapy?
teriparatide
prolactinoma - treatment?
- dopamine agonists (cabergoline, brmoocriptime)
- surgery
dulaglutide, exenatide, liraglutide - what class of meds are these?
GLP-1 receptor agonists
which antihyperglycemics can cause weight loss?
- biguanides (metformin)
- GLP-1 agonists (-tides)
canagliflozin, dapagliflozin, empagliflozin - what class of meds are these?
SGLT-2 inhibitors
linagliptin, sitagliptin, saxagliptin - what class of meds are these?
DPP-4 inhibitors
pioglitazone - what class of med is this?
thiazolidinediones
side effects of thiazolidinediones?
- edema, HF
- bone fractures
sulfonylureas (glimepriride), meglitinidies (repaglinide, nateglinide) - what class of meds are these?
insulin secretagogues
which oral antihyperglucemics can cause hypoglycemia?
insulin secratagogues
- sulfonylureas (glimepiride
- meglitinides (repaglinide, nateglinide)
what are the causes of low Ca?
- vit D deficiency
- hypopara
- pseudohypopara
- hyperphosphatemia
vit D deficiency - phos and PTH are low/high?
- phos low
- PTH high
hypopara - phos and PTH are low/high?
- phos high
- PTH low
pseudohypopara - phos and PTH are low/high?
- phos high
- PTH high
hyperphosphatemia - phos and PTH are low/high?
- phos high
- PTH high
pseudohypopara - what is mechanism?
end organ resistance to PTH
plasma ACTH are always measured at the same time as what other test?
cortisol
what age start screening for osteoporosis?
65 unless risk factors (fam history, steroid use, smoking, malabsorption, body weight <127lb)
what is secondary hyperpara?
increase in PTH 2/2 low calcium
in what condition do you most commonly see secondary hyperpara?
CKD
what is tertiary hyperpara?
parathyroid has hypertrophied from being stimulated so long in secondary hyperpara that it begins to produce PTH autonomously
incidental adrenal mass - what workup need to send?
- BMP
- dex suppression test
- 24h urine catecholamine
- metanephrine
- vanillylmandelic acid
- 17-ketosterid
when to excise adrenal mass?
- > 4cm
- functional tumors
- malignant tumors (heterogenous appearance on imaging)
osteitis fibrosa cystica - what is it? what causes it?
- increased bony turnover causing fibrous tissue replacement
- caused by primary hyperpara or secondary hyperpara (as in CKD)
to keep organs of braindead patient alive - what do?
- fluids
- vasopressin prn
- methylpred
- thyroid hormone
