MKSAP Board Basics Endocrinology Flashcards
What’s the difference between type 1A and 1B diabetes mellitus?
Type 1A - Autoimmune with specific autoantibodies (e.g. GAD-65, IA-2) detectable.
Present in more than 90% of cases.
Type 1B - Idiopathic, no autoimmune markers,
More common in those with Asian/African ancestry.
Is it best to give basal insulin in the morning or at night?
At night
What causes “dawn phenomenon”? (Where does the glucose come from?)
Hepatic gluconeogenesis
How do you fix (i.e. reset) hypoglycemia unawareness?
Allowing the average plasma glucose to increase for several weeks
What percentage of type 2 diabetes mellitus patients have microvascular disease at the time of presentation?
20%
What percentage of type 2 diabetes mellitus patients have macrovascular disease (e.g. CAD or peripheral vascular disease at time of presentation?
More than 20%
What percentage of patients in the United States with diabetes mellitus have MODY (maturity-onset diabetes of youth)?
5%
At what age does MODY present?
Below 25 years
USPSTF recommends screening for abnormal blood glucose as part of cardiovascular risk assessment in adults aged ________________ who are overweight or obese.
40 - 70 years
What are the risk factors for diabetes mellitus that should prompt screening?
Family history of diabetes mellitus
History of gestational diabetes
PCOS
Certain racial/ethnic groups.
Obese/overweight adults between 40 - 70 years old.
The American Diabetes Association recommends screening overweight adults with one additional risk factor, and all adults aged ____.
Over 35 years
What is the definition of overweight in Asian Americans?
BMI equal to or more than 23 kg/m2
What are the screening tests used for diabetes mellitus?
Fasting plasma glucose level
2-hour post-prandial glucose during oral glucose tolerance test
HbA1c
How many screening tests do you need to diagnosis diabetes mellitus?
2
If 2 simultaneous screening tests are abnormal - diagnose diabetes mellitus; if only one is abnormal then repeat the abnormal one.
How can you diagnose diabetes mellitus on the basis of a random glucose level?
A single random glucose level of > 200 mg/dL along with symptoms of hyperglycemia (polyuria, polydipsia, polyphagia) is diagnostic of diabetes mellitus.
What 2-hr glucose value during an OGTT is diagnostic of diabetes mellitus?
200 mg/dL or over
What 2-hr glucose value during an OGTT is diagnostic of pre-diabetes?
140 - 199 mg/dL
What reduces risk of developing diabetes mellitus in patients with pre-diabetes more - metformin or lifestyle modifications?
Lifestyle modifications
Can an insulin pump increase adherence in a patient who is not adherent to multiple daily insulin injections?
No
What percentage of patients taking metformin develop vitamin B12 deficiency?
5 - 10%
At what GFR is metformin contraindicated?
Less than or equal to 30 mL/min/1.73 m2
Which 3 diabetes mellitus drug classes cause weight loss?
GLP1 agonists
SGLT2 inhibitors
Amylinomimetics (pramlintide)
How do you screen for diabetic neuropathy?
10 g monofilament
128-Hz tuning fork
Pedal pulses
Ankle reflex
When should you start screening for complications in type 1 diabetes mellitus?
5 years after initial diagnosis (continue annually thereafter)
When should you start screening for complications in type 2 diabetes mellitus?
At the time of diagnosis (continue annually thereafter)
What are the indications for a moderate intensity statin in patients with diabetes mellitus?
Age over 40 years and an ASCVD risk of less than 7.5%
(AHA/ACC)
Age 40 - 75 years and an ASCVD risk of 10% or more
(USPSTF)
What are the indications for a high intensity statin in patients with diabetes mellitus?
Coronary artery disease, peripheral vascular disease or ASCVD risk of 7.5% or higher.
(AHA/ACC)
Age 40 - 75 years and an ASCVD risk of 10% or more
(USPSTF)
What is the goal blood pressure in patients with diabetes mellitus?
< 130/80 mmHg (ACC/AHA)
< 140/90 mmHg (ADA)
Urine albumin excretion higher than ______ indicates diabetic nephropathy
30 mg/g of creatinine
Dot-and-blot hemorrhages and clusters of hard, yellowish exudates are characteristic of _______
Non-proliferative diabetic retinopathy
Neovascularization (a network of new blood vessels) protruding from the optic nerve is characteristic of _______
Proliferative diabetic retinopathy
How can you prevent diabetic retinopathy?
Blood glucose control
Blood pressure control
Smoking cessation
Treatment options for severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy.
Panretinal laser photocoagulation
Intraocular injections of bevacizumab or ranibizumab
Treatment options for macular edema in diabetes mellitus patients.
Intraocular injections of bevacizumab or ranibizumab
Treatment options for gastroparesis in patients with diabetes mellitus.
Small feedings
Metoclopramide
Erythromycin
What is the treatment of diabetic mononeuropathy (e.g. third nerve palsy)?
Nothing.
Symptoms resolve spontaneously.
What is the definition of hyperglycemic hyperosmolar syndrome?
Plasma osmolality > 320 mOsm/kg H2O
Glucose > 600 mg/dL
No/low ketones.
No acidosis.
What diagnosis should be considered in any older patient with altered mental status and hypovolemia?
Hyperglycemic hyperosmolar syndrome
What fluids should you use in hyperglycemic hyperosmolar syndrome?
Normal saline first to replenish extracellular space.
Hypotonic fluids after blood pressure is restored and urine output is established.
When should you give IV insulin in patients with hyperglycemic hyperosmolar syndrome?
After expansion of the intravascular space has begun.
When should you switch to subcutaneous insulin in patients with hyperglycemic hyperosmolar syndrome?
Once blood glucose is less than 200 mg/dL and the patient is eating.
Which fluids should you give in diabetic ketoacidosis?
Normal saline for immediate volume replacement and switch to 0.45% saline if the sodium is high or normal after the initial bolus.
When should you start potassium replacement in diabetic ketoacidosis?
When potasstium is < 5.5 meq/L
When should you start the glucose infusion along with the insulin infusion in a patient with diabetic ketoacidosis?
When the blood glucose is less than 250 mg/dL
When do you replace the potassium in a patient with diabetic ketoacidosis?
When serum potassium is less than 5.5 mEq/L
What do you do if a patient with diabetic ketoacidosis presents with a serum potassium of less than 3.3 mEq/L?
Delay the initiation of the insulin infusion.
Is severe acidosis in diabetic ketoacidosis treated with bicarbonate?
No. Evidence of benefit is lacking.
What is the glucose goal for critically ill patients in the hospital?
140 - 180 mg/dL
What is the treatment for critically ill patients in the hospital with glucose levels above 180 - 200 mg/dL
Insulin infusion
Is tight inpatient glycemic control (80 - 110 mg/dL) recommended for hospitalized patients with diabetes mellitus?
No.
It is not consistently associated with improved outcomes and may increase mortality.
What is the recommended medication for hospitalized patients with diabetes mellitus?
Insulin
Can oral or non-insulin drugs be considered in hospitalized patients with diabetes mellitus type 2?
Only if patients are stable with no anticipated changes in nutrition or hemodynamic status.
How are pregnant women screened for gestational diabetes?
Screening at 24 - 28 weeks with 75 gram 2-hr OGTT
How often should patients with a history of gestational diabetes be screened for development of type 2 diabetes mellitus after delivery?
Annually
What is the target HbA1c is pregnancy to decrease risk of congenital malformations and fetal loss?
Within 1% of normal i.e. 6.6% or lower.
What are the glycemic targets during pregnancy?
Premeal glucose: < 95 mg/dL
1-hr post-prandial: < 140 mg/dL
2-hr post-prandial: < 120 mg/dL
What is the medication of choice in gestational diabetes?
Insulin
How often should patients with diabetes mellitus be screened for diabetic retinopathy during pregnancy?
Once per trimester
Which blood pressure medications can safely be used during pregnancy?
Methyldopa
Beta-blockers (except atenolol)
Calcium channel blockers
Hydralazine
When should you evaluate a patient for hypoglycemia?
When they meet Whipple’s triad:
- Neuroglycopenic symptoms
- Glucose < 55 mg/dL
- Resolution of symptoms with glucose ingestion
What are the types of hypoglycemic disorders?
Fasting
Post-prandial
What evaluation needs to be done in all patients with fasting hypoglycemia?
Screen for use of hypoglycemic agents e.g. insulin or sulfonylurea.
MEN1
- Primary hyperparathyroidism (multigland)
- Pituitary adenoma
- Pancreatic neuroendocrine tumors
How is an insulinoma diagnosed?
72-hr fast with the following results:
Fasting plasma glucose < 45 mg/dL
Serum insulin > 5 - 6 mU/L
Elevated C-peptide level
What is the imaging study of choice after an insulinoma is diagnosed?
CT abdomen
What happens to the C-peptide levels in case of surreptitious use of oral hypoglycemic agents (e.g. sulfonylureas or meglitinide)?
Inappropriately elevated at time of hypoglycemia
What happens to the C-peptide levels in case of surreptitious use of insulin?
Low at the time of hypoglycemia
Are home glucometers accurate?
For the most part but they can be inaccurate in the hypoglycemia range.
Do patients who don’t have Whipple’s triad need to be evaluated for hypoglycemia?
No
How do you treat acute hypoglycemia?
Oral carbohydrates
IV glucose
IM glucagon
What is the most common cause of hypopituitarism?
Pituitary adenoma
What diagnosis should be considered when a patient presents with sudden onset headache, visual changes, ophthalmoplegia, and altered mental status?
Pituitary apoplexy (sudden pituitary hemorrhage or infarction)
What diagnosis should be considered in patients presenting with amenorrhea, post-partum inability to lactate, and fatigue?
Sheehan syndrome (postpartum pituitary necrosis)
When do most cases of lymphocytic hypophysitis occur?
During or after pregnancy
What are non-hormonal symptoms of pituitary adenomas (mass effect)?
- Peripheral vision loss
- Headache
What is the most accurate way to test for secondary adrenal insufficiency?
Metyrapone stimulation test
Which two steroids are measured in a metyrapone stimulation test?
- Cortisol
- 11-deoxycortisol
What is the imaging of choice for a pituitary problem?
Pituitary MRI
Should FSH/LH be measured in women with normal menstrual cycles when assessing for pituitary problems?
No
Should growth hormone be measured or IGF-1 - and why?
IGF-1
Growth hormone is pulsatile
What is the treatment of a pituitary apoplexy?
Glucocorticoids until adrenal insufficiency is ruled out.
May need urgent neurosurgical decompression.
What is thyroid hormone replacement based on in patients with secondary hypothyroidism?
Free T4 levels
What should you do before treating secondary hypothyroidism with thyroid hormone replacement?
Treat or rule out adrenal insufficiency
What happens to the serum sodium levels in adrenal insufficiency?
Stay normal or go low.
(Adrenal insufficiency is a cause of hyponatremia)
What is a pituitary microadenoma?
Pituitary adenoma less than 1 cm in size
What is a pituitary macroadenoma?
Pituitary adenoma 1 cm or larger in size
What non-pituitary conditions can cause enlargement of the pituitary gland?
- Untreated primary hypothyroidism
- Pregnancy
What is the confirmatory test for acromegaly?
Oral glucose tolerance test to suppress growth hormone
What are the tests to confirm Cushing’s disease?
24-hr urine collection for cortisol
Dexamethasone suppression test
Late night salivary cortisol
ACTH (elevated or inappropriately normal in Cushing’s disease)
Which patients with primary hyperparathyroidism need to be evaluated for a pituitary adenoma?
Those with a family history of MEN1
Can psychotropic agents cause hyperprolactinemia?
Yes
Can protease inhibitors cause hyperprolactinemia?
Yes
Can opiates cause hyperprolactinemia?
Yes
Can methyldopa cause hyperprolactinemia?
Yes
Can beta-blockers cause hyperprolactinemia?
No
Can calcium channel blockers cause hyperprolactinemia?
Yes
Can domperidone cause hyperprolactinemia?
Yes
Can metoclopramide cause hyperprolactinemia?
Yes
Can tricyclic antidepressants cause hyperprolactinemia?
Yes
Can anti-seizure medications cause hyperprolactinemia?
Yes
What should you get in all women with hyperprolactinemia?
Pregnancy test
TSH level
What should you get in all patients with hyperprolactinemia?
TSH level
(Primary hypothyroidism causes hyperprolactinemia)
In patients with hyperprolactinemia - what is the usual level of prolactin if this is caused by drugs or a “non-prolactinoma” condition?
< 150 ng/mL
What kind of pituitary adenomas should you treat with “observation”?
- Non-functioning pituitary microadenomas
- Microprolactinomas in women with normal menstrual cycles
What kind of pituitary adenomas should you treat with a dopamine agonist?
Prolactinoma that is symptomatic
What is the recurrence rate of treated prolactinomas after they disappear off imaging?
Up to 50%
What kind of pituitary adenomas should you treat with surgery?
- Secreting anything other than prolactin
- Causing symptoms or mass effect (vision problem, hypopituitarism)
- Prolactinomas unresponsive to dopamine agonists
What conditions should you test for in patients with polyuria?
- Diabetes mellitus
- Diabetes insipidus
- Hypercalcemia
How is the diagnosis of diabetes insipidus confirmed?
- Water deprivation test: inability to concentrate urine
- Urine osmolality < 200 mOsm/kg H2O
How do you differentiate between central and nephrogenic diabetes insipidus?
Desmopressin challenge test
What is the imaging study of choice if the desmopressin challenge test is positive (i.e. urine concentrates) in diabetes insipidus?
MRI pituitary
What is the imaging study of choice if the desmopressin challenge test is negative (i.e. urine does not concentrate) in diabetes insipidus?
Renal ultrasound