Endocrine Flashcards
1
Q
What 2 electrolyte abnormalities cause nephrogenic DI?
A
High calcium
Low potassium
*Block ADH’s effect on kidney
2
Q
2 ways pituitary can be damaged?
A
Compression (tumors)
Damage (trauma, radiation, stroke, infection)
3
Q
Prolactin deficiency manifestations in women & men?
A
Women: NO lactation after delivery
Men: nothing
4
Q
LH or FSH deficiency manifestations in women & men?
A
Women: amenorrhea (no ovulation or menstruation)
Men: erectile dysfxn & decreased muscle mass
Both = decreased libido
5
Q
What normally inhibits release of prolactin?
A
Dopamine
6
Q
Decreased FSH/LH from decreased GnRH w/ anosmia?
A
Kallman syndrome
7
Q
GH deficiency in women & men?
A
Children: short stature
Adults: few symptoms (other stress hormones available)
8
Q
What electrolyte abnormality is common in panhypopituitarism?
A
Hyponatremia (low sodium): from hypothyroidism & isolated glucocorticoid underproduction
Potassium is NORMAL b/c aldosterone excretes potassium
9
Q
Explain Metyrapone test?
A
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)
10
Q
Explain insulin test?
A
Normally, insulin decreases glucose and GH (stress hormone) should rise
In panhypopitutarism, don’t have rise of GH
11
Q
What hormone is affected in DI? Explain difference in central vs nephrogenic?
A
ADH
Central: no ADH release, but kidney is fine
Nephrogenic: normal ADH, kidney unresponsive to it
12
Q
Common causes of nephrogenic DI?
A
Hypercalcemia Hypokalemia Lithium Amyloidosis Myeloma
13
Q
Explain serum and urine findings for Na levels and osmolarity?
A
Serum Na = high (water loss)
Serum osm = high (water loss)
Urine Na = low (dilute)
Urine osm = low (dilute)
14
Q
What symptoms result from hypernatremia?
A
CNS
Confusion, disorientation, lethargy, coma
15
Q
Vasopressin effect on central vs nephrogenic DI?
A
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)
16
Q
Treatment for central & nephrogenic DI?
A
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
17
Q
Most common cancer associated w/ acromegaly?
A
Colon cancer
18
Q
Signs of acromegaly?
A
Increasing hat, ring, shoe size Carpel tunnel Teeth widening Deep voice Body odor Joint pain
19
Q
Best initial test for acromegaly?
A
IGF level
20
Q
What hormone is co-secreted w/ GH?
A
Prolactin
21
Q
Tx of choice for acromegaly?
A
1) Surgery
2) if surgery fails –> medication (pegvisomant = GH receptor blocker)
22
Q
Causes for hyperprolactinemia?
A
Co-secretion w/ GH Hypothyroidism --> high TRH level stimulates prolactin secretion Pregnancy Antipsychotic drugs Methyldopa Opioids Verapamil
23
Q
Signs of hyperprolactinemia in women and men?
A
Women: galactorrhea, AMENORRHEA, infertility
Men: erectile dysfxn, decreased libido
24
Q
Diagnostic tests for hyperprolactinemia?
A
Thyroid function tests
PREGNANCY test
BUN/Ct (kidney disease elevates prolactin)
LFTs (cirrhosis elevates prolactin)
25
Treatment of hyperprolactinemia?
Dopamine agonists --> Cabergoline
26
What drug causes hypothyroidism?
Amiodarone
27
Hypothyroidism SLOWS everything down in the body except what?
Menstrual flow (increased)
28
Thyroid studies in hypothyroidism?
Tx for hypothyroidism?
Elevated TSH
Low T4
Tx: levothyroxine (synthroid)
29
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
Proptosis
Myxedema
Initial therapy = STEROIDS (decrease glycosaminoglycan deposition behind the eyes)
30
Form of hyperthyroidism with:
Tender nodule?
High TSH?
Tender nodule = subacute thyroiditis
High TSH = pituitary adenoma
31
Treatment for:
Graves?
Subacute thyroiditis?
```
Graves = radioactive iodine
Subacute = aspirin
```
32
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)
33
If a thyroid nodule is found, what is first thing to assess?
1) Is it HYPER-functioning by TSH/T4
| 2) If normal = biopsy
34
First sign to presence of Diabetes Insipidus (DI)?
High volume NOCTURIA
35
MEN 2A characterized by what 3 entities?
MEN 2B characterized by what 2 entities?
MEN 2A:
1) Medullary thyroid cancer
2) Pheo
3) Hyperparathyroidism (high calcium)
MEN 2B:
1) Medullary thyroid cancer
2) Pheo
3) Ganglioneurmatosis
36
Why are Cushing syndrome/disease patients at increased risk of DVT?
Increased Factor 8 and vWF complex with decreased fibrinolytic activity
37
Hypothyroidism can cause what metabolic abnormalities?
Hyperlipidemia --> due to decreased LDL surface receptors and/or decreased LDL receptor activity
38
Treatment of AFib in hyperthyroidism?
B-blocker (because of increased sensitivity of beta-receptors to sympathetic stimuli)
39
Diabetes medication that is also used for weight loss?
GLP-1 agonist (glucagon like peptide)
*some association w/ pancreatitis
40
What hormone is elevated in patients with androgen-producing adrenal tumors?
DHEA-S
41
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
42
How will TSH, T3/T4, and radioactive nucleotide uptake values look in exogenous thyroid hormone ingestion?
Factitious thyrotoxicosis --> NO goiter or exophthalmos
LOW TSH
HIGH T3/T4
RAIU LOW
43
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
44
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 storm
Thyroid function tests & propranolol
45
What presents as galactorrhea and amenorrhea in women and hypogonadism in men?
What is the primary treatment?
Prolactinoma
*Dopamine agonists --> dopamine (-) prolactin secretion
Bromocriptine, cabergoline
46
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
47
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
48
How does a pituitary adenoma respond to dexamethasone suppression test?
Is suppressed ONLY with HIGH dose dexamethasone!
49
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**
50
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!!
51
Most common cause of thyrotoxicosis with reduced thyroid uptake?
Subacute granulomatous thyroiditis
*Intense thyroid pain
52
Untreated hyperthyroidism can result in what 2 conditions?
Rapid bone loss (increased osteoclast activity)
| AFibrillation
53
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
54
Which anti-thyroid medication causes hepatic failure?
PTU
55
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!!!
56
In diabetes, what is the first change to occur in the kidneys?
Glomerular hyperfiltration
ACEi help REDUCE intraglomerular hypertension by dilating Efferent arteriole
57
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?
Glucagonoma
*Causes diabetes (high blood sugar), necrolytic migratory erythema, diarrhea, wt loss
58
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
5) HDL
59
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!
60
Proper order of treatment for pheo?
1) a-blocker (prevent unopposed alpha stimulation and increased BP)
2) b-blocker
61
Side effect of methimazole?
Agranulocytosis
62
Episodic flushing is hallmark for what?
Other s/s?
Diagnostic test?
Carcinoid syndrome
Flushing, diarrhea, telangectasias, bronchospasm
*Tricuspid regurgitation --> common heart defect
5-HIAA in urine
63
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)
64
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?
Mucosal neuromas
*MEN 2B --> MTC, Pheo, Mucosal neuromas, Marfanoid features
RET proto-oncogene
65
Electrolyte abnormality in DKA?
Hyperkalemia --> acidosis causes H+ to move intracellularly in exchange for K moving outward
66
What are common s/s in hypothyroidism?
Weight gain
Fatigue
Constipation
Concentration changes
67
In someone with hypocalcemia, what initial causes should be considered?
Hypoalbuminemia
Hypomagnesiemia
Recent blood transfusion (citrate)
Drugs (phenytoin, bisphosphonates)
68
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
69
If someone has muscle weakness, slowed DTRs, and elevated serum CK, what should be the first initial test?
How is this different than polymyositis?
TSH/free T4
*SLOW DTRs
Can be proximal muscles, myalgias
*Polymyositis = normal DTRs
70
Person has unexplained elevated CK + myopathy?
Hypothyroidism
71
What s/s suggest primary adrenal insufficiency?
What initial test?
Confirmatory test?
Hyponatremia, hyperkalemia, anemia
*Increased pigmentation
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
72
Synthetic analogue of ACTH?
Analogue of ADH?
Cosyntropin
Vasopressin
73
What electrolyte abnormality is common in chronic steroid use (Cushing syndrome)?
Hypokalemia
*Corticosteroids have some mineralocorticoid activity and will bind to aldosterone receptors in the kidney
74
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
75
What antibodies are most prevalent in:
Hashimoto's?
Graves?
Hashimoto's = anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin antibody
Graves = thyroid-stimulating immunoglobulins (TSI) --> stimulate TSH receptors
76
A person with carcinoid syndrome is at risk for developing a deficiency in what vitamin or mineral?
Niacin
*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
77
Hashimoto's thyroiditis predisposes you to increased risk of developing which thyroid disorder?
Thyroid lymphoma
78
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
79
Acne-like eruption characterized by erythematous follicular papules on the face, trunk, extremities and comedones are NOT present. What is the cause?
Steroid use
80
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
* Erythrocytosis, hepatotoxicity
81
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
82
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?
Toxic adenoma
*Thyroxicosis = RAI shows uptake in adenoma only with remainder of gland suppressed
83
Pathophys behind familial hypocalciuric hypercalcemia?
Abnormal Ca-sensing receptors on the parathyroid cells and renal tubules
Parathyroid --> blocks normal Ca-induced PTH suppression = high/normal PTH levels
Renal tubules --> defective Ca-sensing receptors cause excess Ca reabsorption = LOW urinary Ca levels
Urine Ca/Cr ratio =
