Endocrinology

Question 1

Tests for DM-I

Answer 1

C-peptide: endogenous insulin production (will be very low in type 1)
GAD antibodies: attack islet cells (will be elevated in type 1)

Question 2

What lab test is important before starting metformin

Answer 2

Creatinine clearance
can cause lactic acidosis if CrCl<30
be cautious in patients with Cr>1.4

Question 3

MOA of sulfonylureas

Answer 3

think milk insulin from pancreas
works better for newly dx DM-II in younger pts
glipizide
glyburide

Question 4

Metformin MOA

Answer 4

dec glucose production by liver

sensitizes insulin to use glucose

Question 5

Thiazolidinediones MOA

Answer 5

helps muscle utilize glucose
Avandia (rosiglitazone)
Actos (pioglitazone)

Question 6

SGLT-2 MOA

Answer 6

pee out glucose (NOT kidney protective)
Steglatro (ertugliflozin)
Invokana (canagliflozin)
Jardiance (empagliflozin)
Farxiga (dapagliflozin)

Question 7

GLP-1 MOA

Answer 7

activated glucagon-like-peptide-1 (GLP-1) receptor:
-increasing insulin secretion
-decreasing glucagon secretion
-delays gastric emptying 
decrease appetite
cardio and nephro protective
Bydureon (exenatide)
Byetta (exenatide)
Lyxumia (lixisenatide)
Trulicity (dulaglutide)
Victoza (liraglutide) 
Ozempic (semaglutide)
Rybelsus (semaglutide)

Question 8

Xigduo generic

Answer 8

dapagliflozin/metformin

SGLT2

Question 9

Soliqua generic

Answer 9

lixisenatide/insulin glargine

GLP-1

Question 10

Xultophy generic

Answer 10

liraglutide and insulin degludec

GLP-1

Question 11

Diabetes Mellitus
Path:
Pt:
Dx:

Answer 11

Path: Abnormal carbohydrate metabolism

Pt:polydipsia, polyphagia, polyuria, weight loss, blurry vision

Dx:

• Symptoms + random plasma glucose >/= 200
• Fasting plasma glucose >/= 126 on 2 separate occasions
• Plasma glucose >200 2 hours after a 75g glucose load during oral glucose tolerance test
• HgA1c >/= 6.5% (adults only)

Question 12

Which class of antidiabetic drug should be avoided in patients with a family or personal history of medullary thyroid carcinoma?

Answer 12

GLP-1 (-tide)

Question 13

type 2 non-insulin dependent diabetes mellitus presents to the clinic with recurrent vaginal yeast infections. Which of the following medications is most likely contributing to her chief complaint?

Answer 13

SGLT-2 (-gliflozin)

Question 14

Cushing Disease
Path:
Pt:
Dx:
Tx:

Answer 14

Path: ACTH-secreting pituitary tumor

Pt: amenorrhea, central obesity, depressive symptoms, and easy bruising
bitemporal hemianopsia (pituitary adenoma)
PE: purple striae, moon face (facial adiposity), buffalo hump (increased adipose tissue in the neck and upper back), and hypertension

Dx: 24 hr urine cortisol and testing ACTH levels

Tx: transsphenoidal removal

Question 15

Adrenal insufficiency 
Path:
Pt:
Dx:
Tx:

Answer 15

Path:
Primary (Addison’s disease)- destruction of adrenal gland-> lack of cortisol, aldosterone, and sex hormones
Secondary- deficient ACTH from pituitary-> lack of cortisol (aldosterone & RASS intact)
-Glucocorticoid cessation- esp w/ prolonged use and abrupt cessation
-Hypopituitarism (rare)

Pt:
Low cortisol:
weakness, myalgias, fatigue, weight/appetite loss, N/V/D, abdominal pain, headaches, sweats, irregular periods
Mild hyponatremia, salt craving, hypotension, hypoglycemia
Primary only (dec aldo and sex hormones, inc ACTH)
-Hyperpigmentation-> inc ATCH stimulation of melanocytes
-Dec aldo: orthostatic hypotension, hyponatremia, hyperkalemia, non-anion gap acidosis, hypoglycemia, dec BUN
-Dec sex hormones: dec libido, amenorrhea, loss of axillary and public hair

Dx:
-Cosyntropin (ACTH) stimulation test- screening for adrenal insufficiency, little/no inc cortisol-> adrenal insufficiency
-CRH stimulation test- differentiates etiologies
Primary/Addisons (Adrenal)- inc ACTH levels and dec cortisol
Secondary (pituitary)- dec ACTH and dec cortisol (pituitary can’t produce enough ACTH)

Tx:
Hormone replacement
Addisons-> glucocorticoids + mineralocorticoids
Synthetic glucocorticoids: hydrocortisone (1st line), prednisone, dexamethasone
Synthetic mineralocorticoid: fludrocortisone (aldosterone)
Secondary-> only glucocorticoids

Question 16

Hyperthyroidism
Path:
Pt:
Dx:
Tx:

Answer 16

Path: Graves disease (MC)
Autoimmune

Sx: weight loss, heat intolerance, tremor, palpitations, anxiety, increased frequency of bowel movements, SOB

PE: diffuse goiter, stare and lid lag, inc HR, systolic hypertension, hyperglycemia
Graves: pre-tibial myxedema, ophthalmopathy-> proptosis (exophthalmos), impaired eye-muscle function, periorbital and conjunctival edema

Lab:
Low TSH
High serum triiodothyronine (T3); > serum thyroxine (T4)

Tx:
sx: beta blockers (atenolol)
methimazole (a thionamide) except during first trimester (give propylthiouracil/PTU)

Alternatives:
Radioiodine ablation
Surgery

Question 17

DPP-4 Inhibitors MOA

Answer 17

increase incretin levels (GLP-1 and GIP), which inhibit glucagon release, which in turn increases insulin secretion, decreases gastric emptying, and decreases blood glucose levels
Gliptins