Flashcards in Endocrine Deck (83):
What 2 electrolyte abnormalities cause nephrogenic DI?
*Block ADH's effect on kidney
2 ways pituitary can be damaged?
Damage (trauma, radiation, stroke, infection)
Prolactin deficiency manifestations in women & men?
Women: NO lactation after delivery
LH or FSH deficiency manifestations in women & men?
Women: amenorrhea (no ovulation or menstruation)
Men: erectile dysfxn & decreased muscle mass
Both = decreased libido
What normally inhibits release of prolactin?
Decreased FSH/LH from decreased GnRH w/ anosmia?
GH deficiency in women & men?
Children: short stature
Adults: few symptoms (other stress hormones available)
What electrolyte abnormality is common in panhypopituitarism?
Hyponatremia (low sodium): from hypothyroidism & isolated glucocorticoid underproduction
Potassium is NORMAL b/c aldosterone excretes potassium
Explain Metyrapone test?
Metyrapone (-) 11-B hydroxylase = no cortisol release in normal person = ACTH levels rise in normal person
In panhypopituitarism, this test causes no change in ACTH (pituitary not working)
Explain insulin test?
Normally, insulin decreases glucose and GH (stress hormone) should rise
In panhypopitutarism, don't have rise of GH
What hormone is affected in DI? Explain difference in central vs nephrogenic?
Central: no ADH release, but kidney is fine
Nephrogenic: normal ADH, kidney unresponsive to it
Common causes of nephrogenic DI?
Explain serum and urine findings for Na levels and osmolarity?
Serum Na = high (water loss)
Serum osm = high (water loss)
Urine Na = low (dilute)
Urine osm = low (dilute)
What symptoms result from hypernatremia?
Confusion, disorientation, lethargy, coma
Vasopressin effect on central vs nephrogenic DI?
Central: urine becomes concentrated and serum less dilute (ADH can work on functioning kidney)
Nephrogenic: NO changes (still dilute urine b/c no effect of ADH on kidney)
Treatment for central & nephrogenic DI?
Central: vasopressin (desmopressin)
Nephrogenic: correct underlying cause (hypercalcemia, hypokalemia)
*HCTZ, amiloride, NSAIDs --> alters renal countercurrent concentrating ability and causes concentration of urine / NSAIDs block prostaglandins
Most common cancer associated w/ acromegaly?
Signs of acromegaly?
Increasing hat, ring, shoe size
Best initial test for acromegaly?
What hormone is co-secreted w/ GH?
Tx of choice for acromegaly?
2) if surgery fails --> medication (pegvisomant = GH receptor blocker)
Causes for hyperprolactinemia?
Co-secretion w/ GH
Hypothyroidism --> high TRH level stimulates prolactin secretion
Signs of hyperprolactinemia in women and men?
Women: galactorrhea, AMENORRHEA, infertility
Men: erectile dysfxn, decreased libido
Diagnostic tests for hyperprolactinemia?
Thyroid function tests
BUN/Ct (kidney disease elevates prolactin)
LFTs (cirrhosis elevates prolactin)
Treatment of hyperprolactinemia?
Dopamine agonists --> Cabergoline
What drug causes hypothyroidism?
Hypothyroidism SLOWS everything down in the body except what?
Menstrual flow (increased)
Thyroid studies in hypothyroidism?
Tx for hypothyroidism?
Tx: levothyroxine (synthroid)
What form of hyperthyroidism has eye and skin findings? What are they?
Best initial therapy?
Graves disease --> most common cause of double vision over 50 yo
*TSH receptor autoantibodies
Initial therapy = STEROIDS (decrease glycosaminoglycan deposition behind the eyes)
Form of hyperthyroidism with:
Tender nodule = subacute thyroiditis
High TSH = pituitary adenoma
Graves = radioactive iodine
Subacute = aspirin
Treatment of thyroid storm/acute hyperthyroidism?
1) Propranolol --> inhibits target organ effect, inhibits peripheral conversion of T4 --> T3
2) Methimazole or PTU
3) Iodinated contrast material - blocks peripheral conversion of T4 --> T3 and blocks release of existing hormone (acts to clog up the thyroid gland)
If a thyroid nodule is found, what is first thing to assess?
1) Is it HYPER-functioning by TSH/T4
2) If normal = biopsy
First sign to presence of Diabetes Insipidus (DI)?
High volume NOCTURIA
MEN 2A characterized by what 3 entities?
MEN 2B characterized by what 2 entities?
1) Medullary thyroid cancer
3) Hyperparathyroidism (high calcium)
1) Medullary thyroid cancer
Why are Cushing syndrome/disease patients at increased risk of DVT?
Increased Factor 8 and vWF complex with decreased fibrinolytic activity
Hypothyroidism can cause what metabolic abnormalities?
Hyperlipidemia --> due to decreased LDL surface receptors and/or decreased LDL receptor activity
Treatment of AFib in hyperthyroidism?
B-blocker (because of increased sensitivity of beta-receptors to sympathetic stimuli)
Diabetes medication that is also used for weight loss?
GLP-1 agonist (glucagon like peptide)
*some association w/ pancreatitis
What hormone is elevated in patients with androgen-producing adrenal tumors?
What are Charcot joints?
What are exam findings?
Neuropathic damage from diabetes or syphilis resulting in loss of feeling --> progressive damage to feet
Deformity, joint damage w/ swelling and osteophytes on xray
How will TSH, T3/T4, and radioactive nucleotide uptake values look in exogenous thyroid hormone ingestion?
Factitious thyrotoxicosis --> NO goiter or exophthalmos
Person with hypothyroidism develops amenorrhea and galactorrhea - why?
What other neurotransmitter can cause the same effects?
Hypothyroidism --> increased secretion of TRH (which stimulates TSH) --> TRH (+) prolactin secretion = amenorrhea/galactorrhea
*Serotonin & TRH
After surgery, person develops tachycardia, HTN, fever, tremor in her hands, altered mental status, and lid lag. What is it? What is best initial test?
Thyroid function tests & propranolol
What presents as galactorrhea and amenorrhea in women and hypogonadism in men?
What is the primary treatment?
*Dopamine agonists --> dopamine (-) prolactin secretion
What is non-ketotic hyperosmolar syndrome?
What other systemic effects can it cause?
Stress situations (e.g. infection) causes elevation of cortisol and catecholamine levels --> increased glucose levels WITHOUT ketonuria
The hyperglycemia causes osmotic diuresis --> serum hyperosmolarity
Acute hyperglycemia can cause blurred vision due to myopic increase in lens thickness and intraocular hypotension secondary to hyperosmolarity
27 male started on thiazide after coming to ER with BP of 157/93. He later develops hypokalemia while his BP remains elevated. What is the next best step in evaluation?
Serum renin and aldosterone levels
How does a pituitary adenoma respond to dexamethasone suppression test?
Is suppressed ONLY with HIGH dose dexamethasone!
14 yo with Type 1 DM has recent onset fatigue and rash over extensor surfaces of knees and elbows. Labs show Fe-def anemia. What is an appropriate co-screen for this patient?
anti-Tissue Transglutaminase antibodies
**Celiac disease associated with T1DM**
How does estrogen affect thyroid levels?
Estrogen increases SHBG and decreases the clearance of TBG --> causes increased TBG levels and binds up free T4 in circulation
**if on Estrogen and patient is hypothyroid -- need to give MORE levothyroxine!!
Most common cause of thyrotoxicosis with reduced thyroid uptake?
Subacute granulomatous thyroiditis
*Intense thyroid pain
Untreated hyperthyroidism can result in what 2 conditions?
Rapid bone loss (increased osteoclast activity)
What treatment modality for Graves disease can initially worsen the exophthalmos?
Radioactive iodine --> first few days after RAI, the destroyed thyroid cells release excess thyroid hormone that can temporarily worsen hyperthyroid state
Which anti-thyroid medication causes hepatic failure?
Person has s/s of myasthenia gravis. What are the appropriate confirmatory tests?
What following test should be ordered?
EMG and ACh-antibody receptor test
**CT of chest --> screen for THYMOMA!!!
In diabetes, what is the first change to occur in the kidneys?
ACEi help REDUCE intraglomerular hypertension by dilating Efferent arteriole
56 yo woman recent developed diabetes and has had wt loss over 6 months with occasional watery diarrhea. She also has eczematous rash around her mouth that has spread to the R thigh - it now appears as erythematous plaques with central clearing and eroded borders. What is the cause?
*Causes diabetes (high blood sugar), necrolytic migratory erythema, diarrhea, wt loss
What are the criteria for metabolic syndrome?
How many need to be present?
3 of these 5
1) Abdominal obesity > 40 in (men) >35in (women)
2) Fasting glucose > 100-110
3) BP > 130/80
4) Triglycerides >150
How can you differentiate between insulinoma or exogenous insulin use?
C-peptide and proinsulin levels
*C-peptide is cleaved from insulin released from pancreas --> NOT present in exogenous insulin!
Proper order of treatment for pheo?
1) a-blocker (prevent unopposed alpha stimulation and increased BP)
Side effect of methimazole?
Episodic flushing is hallmark for what?
Flushing, diarrhea, telangectasias, bronchospasm
*Tricuspid regurgitation --> common heart defect
5-HIAA in urine
How to differentiate the MEN syndromes?
MEN 1 = 3 P's 0 M (Parathyroid, Pancreas/ZE, Pituitary)
MEN 2a = 2 P's 1 M (Parathyroid, Pheo, MTC)
MEN 2b = 1 P 2 M's (Pheo, MTC, Mucosal neuroma, Marfan-like)
40 yo man has episodes of palpitations, anxiety, and sweating and he also has hypermobile joints. He has a family hx of thyroid cancer. He has a 4-cm hard thyroid nodule. He also has elevated serum calcitonin and metanephrines. What else must you look for?
What gene is implicated?
*MEN 2B --> MTC, Pheo, Mucosal neuromas, Marfanoid features
Electrolyte abnormality in DKA?
Hyperkalemia --> acidosis causes H+ to move intracellularly in exchange for K moving outward
What are common s/s in hypothyroidism?
In someone with hypocalcemia, what initial causes should be considered?
Recent blood transfusion (citrate)
Drugs (phenytoin, bisphosphonates)
What should you consider in hypocalcemia with elevated PTH?
Vit D deficiency, chronic kidney disease
*Check creatinine to r/o kidney disease + check 25-hydroxy vitamin D levels
If someone has muscle weakness, slowed DTRs, and elevated serum CK, what should be the first initial test?
How is this different than polymyositis?
Can be proximal muscles, myalgias
*Polymyositis = normal DTRs
Person has unexplained elevated CK + myopathy?
What s/s suggest primary adrenal insufficiency?
What initial test?
Hyponatremia, hyperkalemia, anemia
Basal early morning cortisol & ACTH --> if low cortisol levels need to do confirmatory test
Confirm with Cosyntropin (synthetic ACTH) --> if NO increase in cortisol after administration = Addison
Synthetic analogue of ACTH?
Analogue of ADH?
What electrolyte abnormality is common in chronic steroid use (Cushing syndrome)?
*Corticosteroids have some mineralocorticoid activity and will bind to aldosterone receptors in the kidney
22 yo has hyperthyroidism. She begins PTU therapy. 2 weeks later, she returns with sore throat. She is febrile and exam shows soft palate, pharynx, and tonsils are red and swollen. What is next best appropriate step?
STOP PTU --> agranulocytosis can occur --> low WBC and infections can result
What antibodies are most prevalent in:
Hashimoto's = anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin antibody
Graves = thyroid-stimulating immunoglobulins (TSI) --> stimulate TSH receptors
A person with carcinoid syndrome is at risk for developing a deficiency in what vitamin or mineral?
*Serotonin is made in carcinoid cells from tryptophan --> tryptophan is used in the production of niacin
Increased tryptophan conversion to serotonin and 5-HIAA = less niacin production
Hashimoto's thyroiditis predisposes you to increased risk of developing which thyroid disorder?
Person with TB develops low Na, elevated K and low glucose on labs. What acid base disturbance would be expected?
Normal anion-gap metabolic acidosis
*TB common cause of adrenal insufficiency (Addison)
*AI --> high K+, high H+, low Na, low glucose
- Aldosterone deficient = normally acts to save sodium (reabsorption) and secrete K+ and H+
*No aldosterone = increased K+ and H+ with low Na
Acne-like eruption characterized by erythematous follicular papules on the face, trunk, extremities and comedones are NOT present. What is the cause?
20 yo male with mild gynecomastia and enlarged spleen. Labs show elevated Hct with normal WBC and platelet count. What is the most probable cause?
Steroid drug abuse (androgens are steroid-derived)
*Gynecomastia, testicular atrophy, aggressive behavior
38 yo male on steroids for sarcoidosis develops progressive R hip pain present on wt bearing and at rest. He has signs of Cushing disease. What is the most likely cause of his hip pain?
Disruption of bone vasculature from steroid use
Person has palpitations and wt loss, HTN and tachycardia. Thyroid has 2x2cm L-sided thyroid nodule. T3/T4 are elevated and TSH is undetectable. RAI scan shows uptake in L thyroid nodule; remained of thyroid is reduced. What is the most likely diagnosis?
*Thyroxicosis = RAI shows uptake in adenoma only with remainder of gland suppressed