Endocrinology Flashcards
Radiation exposure of the thyroid during childhood is the strongest environmental risk factor for thyroid cancer, most commonly:
Papillary cancer
is an add-on therapy to metformin to achieve improvement in hemoglobin A1c level and weight loss.
Liraglutide (Victoza)
Note: potential concerns for development of pancreatitis and medullary thyroid carcinoma with GLP-1 receptor agonists. The patient does not have a personal or family history of these abnormalities to preclude use of liraglutide.
The most common cause of primary adrenal insufficiency in the United States is autoimmune adrenalitis, and positive
21-hydroxylase antibodies are found in approximately 90% of those cases.
Antipsychotic agents cause hyperprolactinemia due to their antidopaminergic effect, which interrupts the inhibition of prolactin by dopamine; risperidone may raise the prolactin level above 200 ng/mL (200 μg/L). When the prolactin level is only mildly elevated (<50 ng/mL [50 μg/L]), it may be reasonable to assume that hyperprolactinemia is a medication side effect. When significantly elevated (>100 ng/mL [100 μg/L]), either the medication needs to be withheld to further assess or a
Pituitary MRI obtained to evaluate for prolactinoma
Treat primary adrenal insufficiency?
Hydrocortisone twice daily and fludrocortisone once daily (i.e. glucocorticoid and mineralocorticoid)
a marker of increased bone turnover, should be measured after radiographic diagnosis of Paget disease of bone
Serum alkaline phosphatase
Is an uncommon cause of thyrotoxicosis that presents following a viral upper respiratory tract infection and is distinguished by a tender or painful thyroid, suppressed thyroid-stimulating hormone, and elevated serum free thyroxine
Subacute thyroiditis
___________________________ significantly prevents the development of clinical neuropathy and reduces nerve conduction and vibration threshold abnormalities in type 1 diabetes mellitus.
Enhanced glucose control
Potent antiresorptive drugs (e.g. bisphosphonates) can cause severe hypocalcemia by impairing efflux of calcium from the skeleton in patients with?
Vitamin D deficiency; it is important to assess vitamin D levels and correct deficiency before beginning treatment with an antiresorptive drug.
Signs of androgen excess such as progressive hirsutism and virilization over a short period of time in female patients suggest the diagnosis of?
an androgen-producing adrenal or ovarian tumor & a CT scan should be done/
Is characterized by reduced serum T3, low or low-normal serum T4, and normal or low (but detectable) serum TSH levels around the time of a sickness/illness?
Nonthyroidal illness syndrome (euthyroid sick syndrome)
Following adrenalectomy for Cushing syndrome, patients require daily
Glucocorticoid (e.g. Hydrocortisone) replacement therapy to allow recovery from prolonged suppression due to hypercortisolism; recovery of adrenal function may take up to 1 year or longer depending on the severity of Cushing syndrome.
In men with specific signs and symptoms of hypogonadism, measuring an
8 AM total testosterone level is indicated; if the testosterone level is low, a second 8 AM confirmatory testosterone level is measured.
In chronic hypoparathyroidism, the goals of therapy are to eliminate symptoms while avoiding complications of therapy; monitoring
Urine calcium excretion is mandatory because hypercalciuria often limits therapy.
Excluding glucocorticoid administration, the most common cause of adrenocorticotropic hormone (ACTH)-independent Cushing syndrome is
an adrenal tumor
____________________________ is the most appropriate management of steroid-induced hypogonadism.
Cessation of anabolic steroid use
For women with hypothyroidism adequately treated with levothyroxine before pregnancy, dosing can be empirically increased by
30% when pregnancy is confirmed (i.e taking an additional 2 tablets of their prepregancy Synthroid dose)
Because gender-affirming hormone therapy limits fertility,
reproductive options should be discussed with patients prior to initiation
Many medications cause falsely high levels of catecholamines or metanephrines including certain
antidepressants e.g Amitriptyline that inhibit norepinephrine uptake; therefore discontinuation of these agents at least 2 weeks prior to testing for pheochromocytoma is recommended
For low-risk osteoporotic women, treatment with antiresorptive therapy for
5 years is sufficient
Metformin may be continued in patients with an estimated glomerular filtration rate of
30 to 45 mL/min/1.73 m2 after consideration of risks and benefits; if metformin is continued, frequent monitoring of kidney function (every 3 months) is recommended
Are first-line pharmacologic therapy for hirsutism, acne, and menstrual dysfunction unless fertility is desired in a patient with polycystic ovary syndrome.
Oral contraceptive agents, that contain 30 to 35 µg of ethinyl estradiol appear to be more effective in managing hirsutism than formulations containing less ethinyl estradiol.
In patients with pituitary tumors,
pituitary hypersecretion should be ruled out by biochemical testing
prior to adrenalectomy for pheochromocytoma to prevent potential hypertensive crisis during anesthesia induction and/or manipulation of the tumor
An α-receptor blockade with phenoxybenzamine or another α-blocker
Note: Because phenoxybenzamine causes vasodilation, an expected consequence of therapy is postural hypotension. To counteract this and allow appropriate dose escalation of phenoxybenzamine, patients are advised to drink plenty of fluids, eat high salt-containing foods, and to make liberal use of the salt shaker at meal times.
Has been shown to reduce cardiovascular-related events and all-cause mortality in patients with type 2 diabetes mellitus and cardiovascular disease
Empagliflozin
After ruling out pregnancy, the initial laboratory evaluation in secondary amenorrhea includes
Measurement of follicle-stimulating hormone, thyroid-stimulating hormone, and prolactin levels
To manage in-patient hyperglycemia,
Scheduled basal insulin or basal insulin plus correction insulin is appropriate for patients who are fasting or who have poor oral intake.
Is a common complication of pituitary surgery that may occur 3 to 7 days following surgery; treatment with fluid restriction will prevent further reduction in sodium levels.
Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
Should be used to treat hyperprolactinemia in women with irregular periods who are trying to conceive.
Dopamine agonist therapy
In persons with a family history of recurrent primary hyperparathyroidism and neuroendocrine tumors arising from the pancreas and tumors of the pituitary gland?
Multiple endocrine neoplasia syndrome 1 (MEN1)
Note: Primary hyperparathyroidism may be the first sign of MEN1
Diagnose vitamin D-dependent hypercalcemia such as Sarcoidosis or lymphoma?
An elevated 1,25-dihydroxyvitamin D level and suppressed parathyroid hormone is diagnostic of vitamin D-dependent hypercalcemia
Women with type 1 or type 2 diabetes mellitus who are planning pregnancy should be counseled on the risk of
development or progression of diabetic retinopathy; rapid improvements in glycemic levels during pregnancy can temporarily worsen preexisting retinopathy.
Note: Dilated eye examinations should occur before pregnancy or in first trimester if not done prior to pregnancy. Patients should be monitored every trimester and then closely for 1 year postpartum as indicated by the degree of retinopathy.
Are recommended as first-line therapy in adult men and women on chronic glucocorticoid therapy with moderate to high fracture risk regardless of age?
Oral bisphosphonates
Signs and symptoms of a _____________________________ are those seen in hyperthyroidism, although laboratory evaluation reveals an elevated free thyroxine (T4) level with an inappropriately normal or elevated thyroid-stimulating hormone level.
Thyroid-stimulating hormone-secreting adenoma
Symptomatic prolactinomas are treated with
Dopamine agonists e.g bromocriptine and cabergoline
During the “honeymoon phase” of type 1 diabetes mellitus to reduce metabolic stress on functioning beta cells and preserve any residual function for as long as possible.
Continuing insulin, even at low doses, is recommended
When administered subcutaneously twice yearly, denosumab suppresses bone resorption, increases bone density, and reduces the incidence of osteoporotic fractures in men and women; the effects of denosumab
are not sustained when treatment is stopped; therefore Denosumab should be continued & not stopped after 5 years of treatment.
In fasting hospitalized patients with type 1 diabetes mellitus,
the basal insulin dose should be decreased, the prandial insulin held to avoid hypoglycemia, and a correction insulin regimen should be added to help manage hyperglycemia.
In all patients with an adrenal mass that is clearly not an adenoma, even in the absence of typical symptoms or hypertension
Biochemical testing (i.e 24-hour metanephrines) for pheochromocytoma should be undertaken
In patients with primary hyperparathyroidism who are undergoing parathyroidectomy surgery, identifying and correcting
Vitamin D deficiency (check 25-hydroxyvitamin D level) is important to avoid postoperative hypocalcemia, which occurs due to rapid flux of serum calcium into bone (hungry bone syndrome).
Initial testing for subclinical Cushing syndrome is a
1-mg overnight dexamethasone suppression test; a cortisol level greater than 5 µg/dL (138 nmol/L) is considered a positive test.
Screen for Cushing syndrome in a patient with an alternate sleep schedule e.g. a night shift worker?
The 24-hour urine free cortisol test for Cushing syndrome is not impacted by either estrogen therapy or sleeping patterns.
Gynecomastia can be an adverse effect of medications such as
spironolactone causes an imbalance between free estrogen and free androgen resulting in glandular breast tissue enlargement.
Malabsorptive disorders such as ________________ may decrease levothyroxine absorption resulting in higher than expected levothyroxine dose requirements.
Celiac disease
When evaluating infertility, both female and male factors should be considered concurrently; _____________ is part of the initial diagnostic evaluation.
Semen analysis
Chronic use of this suppresses gonadotroph function, resulting in hypogonadotropic hypogonadism, which is increasingly recognized as a cause of secondary hypogonadism?
Chronic opioid use
The most common cause of primary amenorrhea is gonadal dysgenesis, most commonly associated with
Turner syndrome (45,X0)
Evaluate postprandial hypoglycemia in a patient without diabetes with a history of Roux-en-Y gastric bypass?
A mixed-meal test consisting of the types of food that normally induce the hypoglycemia should be performed to determine the cause of postprandial hypoglycemia.
Oral, injectable (including joint injections), and even topical glucocorticoids are able to suppress adrenocorticotropic hormone (ACTH) secretion and result in secondary adrenal insufficiency. How do you treat?
Hydrocortisone
Note: Fludrocortisone in addition to hydrocortisone is unwarranted as fludrocortisone is needed only in primary adrenal insufficiency. There is no mineralocorticoid deficiency in secondary adrenal insufficiency.
An early morning (8 AM) serum cortisol of less than 3 μg/dL (82.8 nmol/L) is consistent with cortisol deficiency, whereas values greater than 15 to 18 μg/dL (414.0-496.8 nmol/L) exclude the diagnosis
Treat hypothyroidism with
weight-based replacement dose of levothyroxine (1.6 µg/kg lean body weight) is recommended
Should be obtained once the diagnosis of Cushing syndrome is established to determine if it is ACTH dependent or ACTH independent.
ACTH measurement
In patients receiving thyroxine replacement therapy, initiation of estrogen or raloxifene increases thyroxine-binding globulin levels whereas
testosterone reduces thyroxine-binding globulin levels; in either situation a change in thyroxine dosage may be required.
Treatment for postmenopausal osteoporosis, which reduces the risk for spine, hip, and nonvertebral fractures, and are generally well tolerated with low risk for serious adverse effects.
Alendronate, risedronate, zoledronic acid, and denosumab
This diabetic drug stimulate insulin secretion, and they pose risk for hypoglycemia?
Sulfonylureas e.g Glyburide (that has a long half life)
Recognize medications that interfere with screening for primary aldosteronism
Spironolactone and eplerenone can significantly interfere with interpretation of the plasma aldosterone-plasma renin ratio (ARR) and therefore should be discontinued approximately 6 weeks prior to screening for primary aldosteronism
A hemoglobin A1c goal of what is recommended for older adults with complex medical history and significant comorbidities?
7.5-8.0%
Have been associated with the development of hypophysitis with most patients presenting with the combination of headache, pituitary enlargement, and hypopituitarism?
Checkpoint inhibitors such as nivolumab, ipilimumab, and pembrolizumab
Is recommended for incidental adrenal masses with radiologic features that suggest increased risk of an adrenal malignancy (size >4 cm, density ≥10 Hounsfield units, and absolute contrast washout <50% at 10 minutes)
Adrenalectomy
Causes functional, reversible parathyroid hypofunction and must be excluded before a low or inappropriately normal parathyroid level is attributed to hypoparathyroidism.
Hypomagnesemia
is considered to be safe in those with an estimate glomerular filtration rate (eGFR) greater than 45 mL/minute/1.73 m2 and is contraindicated in those with an eGFR less than 30 mL/min/1.73 m2
Metformin
First-line therapy for toxic adenoma is
Radioactive iodine (131I) therapy or surgery.
Note: Toxic adenoma & multinodular goiter are the second most common cause of hyperthyroidism overall & are most frequently seen in older adults. These autonomously functioning nodules synthesize & secrete thyroid hormones independent of TSH stimulation as a result of activating mutations of the TSH receptor or Gsα. They are usually large and can be easily palpated on examination.
Should be performed at the time of diagnosis of type 2 diabetes:
Screening for dyslipidemia, hypertension, a dilated eye examination, spot urine albumin-creatinine ratio, and a comprehensive foot examination
______________________________ may identify undetected hyperglycemia when preprandial blood glucose values are at target goal, but the hemoglobin A1c is above goal.
Measuring postprandial blood glucose levels
Patients with asymptomatic primary hyperparathyroidism require monitoring of serum calcium and creatinine every
6 to 12 months and bone mineral density of the lumbar spine, hip, and distal radius every 2 years.
Subclinical hypothyroidism is characterized by a serum thyroid-stimulating hormone (TSH) level above the upper limit of the reference range and normal free thyroxine (T4) level; before making this diagnosis, however, transient elevation of serum TSH should be ruled out by repeating the measurement of TSH in
2 to 3 months
Most patients with biochemically confirmed primary aldosteronism should undergo
Adrenal vein sampling to confirm the source of the hyperaldosteronism
This can confirm the presence of thyroid nodules palpated on examination and based on findings can help to determine if fine-needle aspiration is needed to assess for malignancy
Ultrasound
Serum thyroid-stimulating hormone level cannot be used to monitor and assess for adequacy of thyroid hormone replacement dosing in secondary hypothyroidism; the levothyroxine dose is
adjusted based on free thyroxine (T<u>4</u>) levels with the goal of obtaining a value within the upper half of the normal reference range
Treatment for hypoglycemic unawareness is to
Reduce the insulin dose and avoid hypoglycemia in order to provide the body an opportunity to restore the ability to detect hypoglycemia.
Screening for osteoporosis in premenopausal women is
not indicated in the absence of risk factors.
Lifestyle counseling for osteoporosis prevention should be done instead.
Methimazole drug-related agranulocytosis affects between one in 300 and one in 500 patients taking therapy and may present with fever and sore throat; initial management includes
Stopping the drug and assessment of the neutrophil count
An increased risk of diabetic ketoacidosis with mild to moderate glucose elevations has been associated with the use of all the approved
Sodium-glucose transporter-2 (SGLT2) inhibitors (canagliflozin, dapagliflozin, and empagliflozin).
Secondary hypogonadism is characterized by low testosterone level and low or inappropriately normal serum luteinizing hormone and follicle-stimulating hormone concentrations; what’sthe next step?
MRI of the pituitary is typically performed to evaluate secondary hypogonadism in the absence of obvious reversible causes such as drugs.
In patients with myxedema coma, treatment should include?
Intravenous hydrocortisone should be administered before thyroid hormones to treat possible adrenal insufficiency.
Following the administration of glucocorticoids, intravenous thyroid hormone replacement should be initiated. Treatment with levothyroxine is universally recommended. Although controversial, some experts suggest administering liothyronine concomitantly. Once clinically improved, the patient can be transitioned to oral levothyroxine.
Can erroneously increase the hemoglobin A1c level due to an increase in the proportion of older erythrocytes?
Iron-deficiency anemia
Is the treatment of choice for low-risk papillary thyroid cancer that is confined to the thyroid gland, completely resected at surgery, does not demonstrate aggressive pathologic features (lymphovascular invasion or tall cell variant), and has not metastasized.
Lobectomy
A low urine osmolality in the setting of a high serum osmolality and high serum sodium in a patient with polyuria is diagnostic of
Diabetes insipidus
Is a severe manifestation of thyrotoxicosis with life-threatening secondary systemic decompensation; it occurs most commonly with underlying Graves disease coupled with a precipitating factor such as surgery?
Thyroid storm
Is first-line therapy for all patients with type 2 diabetes without contraindications.
Metformin
In patients with diabetic ketoacidosis, intravenous insulin therapy should be continued until complete resolution of the anion gap acidosis; as acidosis improves, it may be necessary to
Reduce the insulin infusion rate and add intravenous dextrose to prevent hypoglycemia
Type 2 amiodarone-induced thyrotoxicosis (destructive thyroiditis) can be treated with
Moderate- to high-dose prednisone that can be gradually tapered over 1 to 3 months.
______________________________ should be considered in patients with abrupt, rapidly progressive, or severe hyperandrogenism as well as in women with marked hyperandrogenemia (total testosterone >150 ng/dL [5.2 nmol/L]).
An androgen-secreting ovarian tumor
Demonstrates greater improvements in glycemic control and cardiovascular risk factors compared with optimized medical therapy and lifestyle modifications.
Metabolic surgery
Related to malabsorption or dietary factors is characterized by low 25-hydroxyvitamin D, calcium, and phosphate levels and elevated parathyroid hormone and alkaline phosphatase levels.
Osteomalacia
