Endocrinology Flashcards
If a pituitary incidentaloma is less than 1cm, what 2 things should be done yearly?
- Prolactin level
2. MRI
How do you manage asymptomatic empty sella syndrome (2 tests)?
Check thyroid and adrenal function
Are there any sx in men who present with prolactin deficiency?
No
What’s the difference between Kallman and Klinefelter syndrome?
Kallman is a KAL-1 mutation and results in decreased FSH and LH from decreased GnRH. Klinefelter is a 47XXY karyotype and is an androgen deficiency through insensitivity to FSH and LH despite HIGH levels.
What’s the tx for both Kallman and Klinefelter?
Testosterone replacement
What’s the other name for ADH deficiency and ADH insensitivity?
Diabetes Insipidus
What’s Central DI?
Pituitary produces less ADH
What’s Nephrogenic DI?
ADH has less effect on the kidney
What 2 electrolytes can inhibit ADH’s effect on the kidney?
Hypercalcemia
Hypokalemia
What disease presents with extremely high-volume urine and thirst, resulting in severe hypernatremia?
Diabetes Insipidus
What’s the first diagnostic test for Diabetes Insipidus?
Desmopressin stimulation test
How do you determine the difference between central and nephrogenic DI?
In central DI: urine volume will decrease and urine osmolal will increase in response to Desmopressin
In nephrogenic DI: no effect on urine volume or osmolality with Desmopressin
How do you treat central DI?
Long-term Desmopressin (vasopressin/ADH)
How do you treat nephrogenic DI?
Correct the underlying cause with HCTZ, amiloride, NSAIDs
What disorder causes enlargement of soft tissue and bone, deepening of voice, colonic polyps, and coarsening facial features?
Acromegaly
What’s the best initial test for acromegaly?
IGF-1 (insulinlike growth factor 1)
What’s the most accurate test for acromegaly?
Glucose suppression test
What do the following drugs raise?: Antipsychotics Methyldopa Metoclopramide Opioids TCAs Verapamil
Prolactin
After finding high prolactin, what labs should you do?
Thyroid
Pregnancy
BUN/Creatinine
Liver function
What’s a medication used to treat prolactinoma that is better tolerated than Bromocriptine?
Cabergoline
What are TSH and T4 levels in hypothyroidism?
High TSH
Low T4
Low/normal T3
When TSH is 2x normal and T4 is normal, do you treat?
Yes
When TSH is high but less than 2x normal and T4 is normal, do you treat?
Only if Antithyroid peroxidase/antithyroglobulin Ab’s are positive
What are the TSH and T4 levels in hyperthyroidism?
Low TSH
High T4
High T3
Only _______ Disease has TSH receptor antibodies?
Graves
Which non-cancerous thyroid disorder has elevated radioactive iodine uptake?
Graves
What medication treats thyroid storm?
Methimazole
What’s the next step in evaluation of a thyroid nodule felt on physical exam?
T4 and TSH levels
Which type of thyroid cancer shows elevated calcitonin?
Medullary carcinoma
If there’s an indeterminate biopsy, do you have to take an entire thyroid nodule out?
Yes
What’s the most common cause of hypercalcemia?
Hyperparathyroidism
What can the following all cause?: Cancer Vit D intox Sarcoidosis/granulomatous Thiazide diuretics Hyperthyroidism Mets to the bone Multiple Myeloma
Hypercalcemia
What does EKG show with hypercalcemia?
Short QT
How is acute hypercalcemia treated?
- Saline hydration at high volume
- Bisphosphonates
- Calcitonin (works faster)
What are the calcium and PTH levels in hyperparathyroidism?
High calcium
High PTH
What are the chloride and phosphate levels in hyperparathyroidism?
Chloride: high
Phosphate: low
What’s the medicine you can give a patient with hyperparathyroidism if they can’t have surgery?
Cinacalcet
Other than prior neck surgery, what else can cause hypocalcemia (3)?
- Hypomagnesemia
- Renal failure
- Vit D deficiency
What are the phosphate levels in vit D deficiency?
Low phosphate
What are the childhood and adult diseases caused by low vitamin D?
Rickets/Osteomalacia
Can hypocalcemia cause a prolonged QT?
Yes
What are the following signs of:? Chvostek sign Carpopedal spasm Perioral numbness Mental irritability Seizures Tetany
Hypocalcemia
In which disease are osteoclasts and osteoblasts working out of sync, deforming the bone. It also has elevated alk phos and normal GGTP.
Paget disease
What’s the most accurate test for Paget disease?
Nuclear technetium bone scan finding patchy areas of osteoblastic activity
What cancer can Paget disease turn into?
Osteosarcoma
If Paget is painful, what tx is used?
Bisphosphonates
If Paget is painless, what tx is used?
None!
If Paget has bone pain not relieved by NSAIDs, what med do you use?
Calcitonin
What’s the difference between Cushing syndrome vs Cushing disease?
Cushing syndrome is the umbrella term for hypercortisolism; Cushing disease is a term used for specifically pituitary overproduction of ACTH
What are the 2 best initial tests for hypercortisolism?
- 24-hour urine cortisol
2. Dexamethasone suppression test
How do you interpret the dexamethasone suppression test?
Dexamethasone should normally suppress the morning cortisol level. If the morning cortisol is high, hypercortisolism is the dx
What’s the best test for establishing the cause of hypercortisolism?
ACTH testing
How do you interpret an ACTH test?
Decreased ACTH = adrenal source
Elevated ACTH = pituitary or ectopic
How do you differentiate between pituitary vs ectopic when there’s elevated cortisol and ACTH?
High dose dexamethasone suppresses pituitary, but does not suppress ectopic
If high dose dexamethasone does not suppress, do you still need a brain MRI?
Yes
What lab value is elevated in hypercortisolism that rhymes with deukocytosis?
Leukocytosis
What size of adrenal mass is suspicious for malignancy?
> 4cm
What is Addison disease?
Hypoadrenalism caused by autoimmune destruction of the gland
How is Addison disease treated?
Hydrocortisone
What is the name of the condition in which there is autonomous overproduction of aldosterone despite high BP and low renin, most often caused by adenoma?
Primary hyperaldosteronism
High BP + hypokalemia = ______ _____________?
Primary hypoaldosteronism
What’s the best test for primary hyperaldosteronism?
Plasma aldo : plasma renin ratio.
How does primary hyperaldosteronism present on labs?
Elevated aldo
Normal renin
Where in the adrenal gland is a pheochromocytoma?
Medulla
What’s the best initial test for suspected pheochromocytoma?
Plasma free metanephrines
What’s the best initial tx for pheochromocytoma before surgery?
Phenoxybenzamine
What does hypoglycemia plus high insulin level (high C peptide) mean?
Insulinoma
How do you treat a glucagonoma?
Octreotide and surgery
What could be the cause of high volume watery diarrhea, hypokalemia, low osmotic gap in stool, and high vasoactive intestinal peptide levels + a pancreas lesion?
VIPoma
How do you treat a VIPoma?
Octreotide and surgery
What condition has issues with: -Parathyroid -Anterior pituitary -Pancreas islet cells ?
MEN1
What condition has issues with: -Parathyroid -Medullary thyroid -Pheochromocytoma ?
MEN 2A
What condition has issues with: -Mucosal neuroma -Medullary thyroid -Pheochromocytoma -Marfanoid ?
MEN 2B
What are the criteria for diabetes diagnosis?
- Single random glucose >200 with sx
- 2 fasting glucoses >125
- A1c >6.5%
Why are sulfonylureas not great as first line tx for T2DM?
They increase insulin release from the pancreas and increase obesity
In whom is Metformin contraindicated?
Those with renal dysfunction
What’s the peak action time of lispro, aspart, and glulisine?
1 hour
What’s the peak action time of regular insulin?
2 hours
What’s the peak action time for NPH?
6-7 hours
What’s the peak action time for glargine?
None, just a steady 24 hour release
When do you replace potassium during DKA?
When it comes down to a level approaching normal
What’s the most accurate test of the severity of DKA?
Bicarb (anion gap)
All patients with DM should receive which vaccine?
Pneumococcal
What’s the BP cutoff for diabetic patients to take ACEi/ARBs?
140/90
What side effect can minoxidil, valproic acid, and phenytoin all cause in women?
Male-pattern hair growth
What drug can you give for PCOS?
Metformin