15. Endocrine, Diabetes, Metabolism

Question 1

Weight gain, hirsutism/menstrual abnormalities (hyperandrogenism) mm weakness, HTN, easy bruisability, dermal atrophy, and striae are signs of what?

Answer 1

Cushing’s syndrome (hypercortisolism)
Dx - once hypercortisolism is confirmed (late-night salivary cortisol assay, 24-h urine free cortisol, overnight low-dose dexaethasone supp test), ACTH levels are measured to differentiate ACTH dependent and ACTH independent causes

Question 2

How can chronic GI disease (eg steatorrhea, Celiac disease) cause vit D def?

Answer 2

Malabsorption –> hypocalcemia low phosphorus, elevated PTH

Question 3

Most appropriate treatment for patient with central DI?

Answer 3

Desmopressin is first line for central DI. HCTZ is not as effective as monotherpay, but can be additive.
Note: can be used to differentiate central and nephro DI - central DI shows at least 50% inc in urine osm after admin.

Question 4

Patient with weight loss, tachy, tremor, and lid retraction should be suspected of having what? What are the cardiovascular effects?

Answer 4

Thyrotoxicosis.
CV: afib/flutter, sinus tachy, premature AV complexes, inc myocardial o2 demand, widen pulse pressure
Systolic HTN is d/t hyperdynamic circulation from inc myocardial contractility and HR

Question 5

Glucocorticoid deficiency, hypogonadism, and hypothyroidism characterize what condition?
sx include fatigue, cold intol, hypoglycemia, anorexia, low libido.

Answer 5

hypopituitarism.

Note: this contrasts from primary adrenal insuff in that ALDOSTERONE is normal in central adrenal insufficiency

Question 6

How can high-volume blood transfusion cause symptomatic hypocalcemia?

Answer 6

Chelation of ionized calcium by citrate in transfused blood.
Sx: paresthesias, carpal spasm, hyperreflexia

Question 7

A young patient with HTN, strong family hx of HTN and stroke, and easily induced hypokalemia after starting a thiazide diuretic suggests what?

Answer 7

Primary hyperaldosteronism.

Test renin and aldosterone

Question 8

How does primary hyperparathyroidism (PHPT) cause HTN? What are common sx of PHPT?

Answer 8

Unclear

Bone pain, kidney stones, GI sx, neuropsych sx (bones, stones, abd moans, and psychiatric groans).

Question 9

What test predicts the risk of future ulcers in patients with diabetic neuropathy

Answer 9

Monofilament test

Question 10

Hypothyroidism can cause what additional metabolic abnormalities

Answer 10

Hypercholesterolemia (dt dec LDL surface receptors/receptor activity) +/- hypertriclyceridemia (d/t dec Lipoprotein lipase activity)
Hyponatremia
Elevated CK and transaminases

Question 11

What are the lab findings in osteomalacia (calcium, phosphate, PTH) due to vit D def?
Sx?

Answer 11

Vit Def
Ca: low
Phosphate: low
PTH: inc
sx: Vit D def (eg d/t malabsorption, bypass surgery, celiac, chronic liver or kidney dz) --> asymp or bone pain, mm weakness or cramps

Question 12

Premature sexual hormone activation (precocious puberty) can occur centrally or peripherally. Isolated premature adrenarche (body odor, oily hair, acne, pubic hair, and axillary hair) is caused by central or peripheral activation? Is bone age normal?

Answer 12

Peripheral - early activation of adrenal androgen release. Bone age normal
Note: obese children and of black or Hispanic ethnicities are at inc risk.
Premature thelarche (breast dev) also has normal bone age

Question 13

Dry mucous membranes, polyuria, dec LOC, diffuse abd pain, metabolic acidosis, following an acute URI is most likely explained by what?

Answer 13

DKA from undiagnosed T1DM.
Infex –> systemic catecholamines and cortisol –> excess glucagon –> hyperglycemia, ketonemia, osmotic diuresis. Net renal loss of K+ with depletion of total K stores.

Question 14

In determining central vs peripheral precocious puberty, what order should you measure bone age, LH, and GnRH?

Answer 14

Bone age first. If advanced, measure baseline LH, give GnRH, then remeasure LH.
Low LH = peripheral (gonadotropin-independent)
High LH = central (gonadotropin dependent)
If bone age normal - isolated breast or isolated pubic hair dev

Question 15

weight loss, abdominal pain, fatigue, hyperpigmentation, hypotension, low serum cortisol, hyponatremia, and hyperkalemia, is suspicious of what? What is the MCC in developed countries?

Answer 15

Primary adrenal insufficiency - autoimmune adrenalitis is responsible for >90% of cases in developed countries.
Autoab against adrenal enzymes that make corticosteroids. Don’t make mineralocorticoids.

Question 16

Order of steps for evaluating secondary amenorrhea?

Answer 16

1. Preg test
2. If neg, Check prolactin, TSH, FSH
3. Inc prolactin –> Brain MRI
   Inc TSH –> hypothyroidism
   Inc FSH –> premature ovarian failure
   Prior uterine procedure/infx –> hysteroscopy

Question 17

What is the MCC of congenital hypothyroidism (poor feeding, constipation, dry skin, large fontanelles)? Tx?

Answer 17

Thyroid dysgenesis (aplasia, hypoplasia, ectopic gland)
Labs: elevated TSH and dec T4
Tx: levothyroxine

Question 18

Which type of thyroid cancer cannot be diagnosed by limited tissue sample bc cytologic findings are similar in both this condition and benign follicular adenomas?

Answer 18

Follicular thyroid cancer - characterized by invasion of the tumor capsule and/or blood vessels. Need to excise the entire nodule to evaluate.

Question 19

In developed countries >80% of patients have primary adrenal insuf (hypotension, pigmentation, hyponatremia, hyperK, eosinophilia, inc ACTH, low cortisol) d/t what?

Answer 19

Autoimmune adrenalitis

Question 20

Hypophosphatemia, hypocalcemia, inc alk phos, hyper PTH in a pt with hx of celiac sprue likely has what?

Answer 20

Osteomalacia d/t defective mineralization of the organic bone matrix from vit D def

Question 21

How do you differentiate painless thyroiditis from Graves disease?

Answer 21

Thyroid radioiodine scintigraphy should be performed
1. pinless: dec radioiodine uptake (release preformed thyroid hormone)
2. Graves: Diffuse inc in radioiodine uptake
Note: Subacute (de Quervain) thyroditis presents with painful goiter

Question 22

what oral anti-diabetic medication promotes weight loss?

Answer 22

GLP-1 agonists (eg exenatide)

Note: drugs such as sulfonylureas, thiazolidinediones can cause weight gain.

Question 23

Serum ca concentration decreases by how much for every 1 g/dL dec in serum albumin?

Answer 23

0.8mg/dL
Note: patients with hypoalbuminemia can have dec total serum ca, but ionized ca (physiologically active form) is hormonally regulated and remains stable.