SAS/Review Flashcards
How do the onset and durations of regular insulin and NPH insulin differ?
- Regular insulin
- Onset in 30 min - 1 hr
- Duration 5-8 hrs
- NPH insulin
- Onset 1-2 hours
- Duration 14-18h
=> if you are giving a patient with diabetes an overnight tube feed over the course of 12 hours, use NPH insulin
Even though I for some reason thougth that NPH insulin is rarely used now?
Does teriparatide result in bone formation or bone resorption?
Formation
(if given intermittently)
Teriparatide = PTH analog
For people with a uterus:
- Average age of pubertal onset:
- Average age of menarche onset:
- Average age of pubertal onset: 10 years (normal - 7/8 - 13)
- Average age of menarche onset: 12.5 years
- Usually when Tanner 4 breast development is present
What hormone levels do you expect (in general) for:
-
Central precocious puberty
- Gonadotropins:
- Sex steroids:
-
Peripheral precocious puberty
- Gonadotropins:
- Sex steroids:
-
Central precocious puberty
- Gonadotropins: high
- Sex steroids: high
-
Peripheral precocious puberty
- Gonadotropins: low
- Sex steroids: high
Describe the effects of the following insulin-mediated pathways
- PI3K:
- Ras/MAPK:
-
PI3K: Stores energy
- GLUT4 activation
- Glycogen synthesis
- Lipid synthesis
- Protein synthesis
-
Ras/MAPK: Uses the energy to grow
- Gene expression
- Cell growth and differentiation
What factors are required to diagnose hypoglycemia? (3)
Whipple’s triad
- Symptoms of hypoglycemia
- Low plasma glucose concentration (measured by blood draw)
- Relief of symptoms when plasma glucose level is raised
Possible sx of hypoglycemia include = behavioral change, confusion, fatigue, seizure, loss of consciousness, palpitations, tremor, anxiety, sweating, hungerm paresthesias
What hormone levels (in general) do you expect during mini-puberty of infancy?
Gonadotropins: pubertal
Estradiol: pubertal
May see breast development (thelarche) and pubic hair (pubarche) - this is normal, as long as it regresses
Which hormone is the primary driver of prenatal growth?
Fetal insulin
Remember; maternal insulin does not cross the placenta, but maternal glucose does
Which diabetes medication is most likely to increase peripheral insulin sensitivity?
Pioglitazone
(Thiazolidinedions in general)
Medullary thyroid carcinoma
- MEN-1 = Pituitary, parathyroid, pancreatic
- Men have 1 PPP
- MEN-2 = Medullary thyroid, pheochromocytoma
- 2A + parathyroid hyperplasia
- 2B + Marfanoid appearance, mucosal neuromas
When in 3% NaCl indicated to treat hyponatremia?
- Rapid development of hyponatremia => correction should be rapid
- Acute symptoms
Chronic hyponatremia = use conivaptan (vasopressin receptor blocker)
Which medications would decrease the size of a somatotroph adenoma? (2)
Which would only treat the symptoms? (1)
Somatotroph adenoma = GH secreting pituitary adenoma
- Decrease size:
- Octreotide
- Cabergoline (use this esp if there is also prolactin secretion)
- Treat symptoms
- Pegvisomant
Which medication would help with post-prandial hyperglycemia AND cause weight gain?
- glimepiride
- pioglitazone
- sitagliptin
- canagliflozin
A. glimepiride
- Sulfonylureas (-amide or -ride) -> weight gain
- TDZs (-glitazones) -> weight gain, but not great for post-prandial
- These drugs increase peripheral insulin sensitivity, but not fast acting
- DPP-4 inhibitors (-gliptin) -> weight neutral/modest weight loss
- SGLT-2 inhibitors (-flozin) -> cause weight loss
What abnormal heart rhythm is associated with severe Graves’ disease?
Atrial fibrillation
What electrolyte abnormalities will be present in a patinet with 21-alpha-hydroxylase deficiency? (3)
Acidosis
Hyponatremia
Hyperkalemia
Also dehydration, hyperpigmentation (high ACTH)
Which lab would you order to evaulate the function of a patient’s hypothalamic-pituitary-growth axis if you could only order 1?
IGF-1
- Synthesized in the liver in response to GH
- GH normally has variabl elevels throughout the day; difficult to get an accurate/useful reading
Describe the “typical” patinet with MODY
-
Strong family hx of diabetes
- Not common in T1DM
-
Normal BMI, generally active/healthy
- Not clinicallly consistant with T2DM
MODY is a rare cause of diabetes, but high on the ddx if the pt is young with normal BMI
List the ranges for fasting glucose for each of the following conditions
- Normal:
- Impaired fasting glucose:
- Diabetes:
- Normal: <100
- Impaired fasting glucose: 100-125 (inclusive)
- Diabetes: >125
What is the most common cause of acromegaly?
GH-secreting pituitary adenoma (aka somatotroph adenoma)
A. Denosunab
What kind of receptor does calcitonin have?
GPCR
What medication(s) would you give to treat low testosterone and oligospermia?
LH and FSH
Giving testosterone alone would not stimulate spermatogenesis
Which class of diabetes medication is associated with increased risk of candidiasis and UTI?
SGLT-2 inhibitors (-flozin)
Are the changes seen in acromegaly reversible?
Cartilage and soft tissue changes are reversible
Bone changes are not
What is the most likey cause of a calcified pituitary mass in a teenager?
Craniopharyngioma
c. RET mutation analysis
* The only diagnostic option listed
Which electrolyte is most important to monitor when giving insulin to correct DKA?
Postassium
- DKA will often have high serum potassium (but low absolute)
- Insulin -> increased Na/K ATPase activity -> shovels K into cells
- -> lowers serum K
- Start repleting K along with insulin as soon as the patient is no longer hyperkalemic
When a patient comes in with elevated calcium, what is the next test you should order?
(if you can only pick one)
Parathyroid hormone
- High or normal PTH => primary hyperparathyroidism
- “inappropriately normal” in the setting of high Ca2+
- Low PTH => PTH-independent cause of hypercalcemia
- PTH should be low in the setting of high Ca2+
- Suspect malignancy, thiazides, Vitamin D or A toxicity, Hyperthyroidism, adrenal insufficiency, sarcoidosis
What is the body’s main source of fuel on day 8 of starvation?
Ketone bodies
(Brain is still using mostly glucose)
B. Inhibition of hepatic gluconeogenesis
Insulin = storage hormone
How will lisinopril (an ACE inhibitor) affect renin and aldosterone levels?
Increased renin
Decreased (to normal) aldosterone
Which diabetes medication is most likely to decrease hepatic gluconeogenesis?
Metformin
What is the mechanism behind hyperglycemia-induced complications?
Formation of advanced glycation end products (AGEs)
- Due to non-enzymatic glycation
- Also, increased sorbital may play a role
What signaling pathway is activated when GLP-1 binds to its receptor?
What are the effects? (3)
Gs -> cAMP
- Insulin secretion
- Decreased gastric emptying
- Decreased glucagon release
D. Von-Hippel Lindau
- Hemangioblastomas + renal masses are pathognomonic for Von-Hippel Lindau
- MEN-2B no renal masses
- Paraganglioma is an extra-adrenal pheochromocytoma
- NFM-1 would also have skin findings (cafe-au-lait spots, subcutaneous neurofibromas)
A
- Decreases glucagon release
- Inhibits catabolic processes
- Increases glucose uptake by myocytes and adipocytes (GLUT4)
What findings are pathognomonic for Von-Hippel Lindau? (2)
Hemangioblastomas + renal masses together
D. Septo-optic dysplasia
(Kallmann syndrome is not a midline CNS defect?)
Malignancy can cause hypercalcemia
Which mechanisms are responsible for this in the following malignancies?
- Solid tumors:
- Multiple myeloma:
- Lymphoma, leukemia:
- Solid tumors: PTHrP secretion
- Squamous cell carcinoma of the lung, head/neck tumors, kidney carcinoma, ovary carcinoma
- Multiple myeloma: Local bone resorption
- Lymphoma, leukemia: Ectopic expression of 1-alpha-hydroxylase -> increaed calcitriol (active vitamin D)
- Renal cell cancer, if overproducing 1-alpha-hydroxylase
List the ranges for 2-hour glucose for each of the following conditions
- Normal:
- Impaired glucose tolerance:
- Diabetes:
- Normal: <140
- Impaired glucose tolerance: [140-200)
- Diabetes: ≥200
How does Van Wyk Grumbach affect puberty?
Van Wyk Grumbach = severe primary hypothyroidism
- High TSH
- -> Cross reacts with FSH and LH receptors
- -> precocious puberty with delayed growth
Which drug is used to treat osteomalacia?
Calcitriol
Osteomalacia = defect in bone mineralization, usually 2/2 vitamin D deficiency
A patient with medullary thyroid cancer is found to have a germline mutation in the RET protooncogene
What genetic syndrome do you suspect?
MEN-2
- 2A more likely than 2B
-
Must check catecholamine levels before surgery
- Need to know if the pt has a pheo before taking them to surgery
For a patient with with Graves’ disease, which treatment would your recommend?
- Radioiodine
- Thyroidectomy
b. Thyroidectomy
Radioiodine can cause exacerbation of Graves’
(When thyroid is dying it can release the pre-stored thyroid hormone)
List 2 diabetes medicaions assoiciated with weight loss
GLP-1 agonists
SGLT2 inhibitors
What is the effect of prolactin on LH and FSH?
Prolactin -> decreased LH/FSH secretion
- Increased prolactin -> amenorrhea, galactorrhea
Your suspect your patient has Hashimoto’s thyroiditis because of hair and skin changes, lethargy, and fatigue, among other symptoms
How should you manage this patient?
Give levothyroxine to treat hypothyroidism
BUT
Before you start that, check adrenal function
- Overlap between pts with Hashimoto’s and Addison’s
- If concurrent Addison’s (hypocortisolism), need to replete cortisol first - giving levothyroixine first will further stress the adrenals -> CRASH
Which type of bone is most at risk of fracture in the setting of hyperparathyroisism?
Corticol bone > trabecular bone
- Trabecular bone = axial skeleton, hips, ankle
- Cortical bone = long bones
- Hyperparathyroidism = increase bone resorption*
- reabsorption is along the surface of trabecular bones, but tunnels through cortical bones*
Which MEN-1 - associated tumor has the highest penetrance?
Parathyroid adenoma
- MEN-1 = Pituitary, parathyroid, pancreatic
- Men have 1 PPP
- Most will have parathyroid adenoma by age 50
MEN-1 = mutation in menin gene on chromosome 11
What is the first sign of central puberty in a person with a uterus?
Thelarche (breast development)
First sign = testicular enlargement in people with testicles
Which insulin preparation has the longest duration of action?
Glargine (20-24h)
Detemir is also long acting, (16-20h)
What is your diagnosis of a patient with low TSH, low T4, and normal T3?
- Hypothyroid
- Euthyroid
- Hyperthyroid
a. Hypothyroid
* Even though the pt has normal T3, low T4 = hypothryroid
