ABIM Endocrinology 1 ā Questions and Answers
Question 1: A 45-year-old woman presents with weight gain, fatigue, constipation, and cold intolerance. TSH is 12 mIU/L and free T4 is low. What is the most appropriate treatment?
- Liothyronine (T3) alone
- Levothyroxine (T4) (Correct answer)
- Methimazole
- Radioactive iodine
Correct answer: Levothyroxine (T4)
Levothyroxine is the standard treatment for primary hypothyroidism and is titrated to normalize TSH levels.
Question 2: A 32-year-old woman with type 1 diabetes presents with recurrent hypoglycemia, nausea, and weight loss. Morning cortisol is undetectable. What additional test should be performed?
- Fasting glucose tolerance test
- ACTH stimulation test (Correct answer)
- 24-hour urinary free cortisol
- Dexamethasone suppression test
Correct answer: ACTH stimulation test
The ACTH (cosyntropin) stimulation test is the gold standard for diagnosing primary adrenal insufficiency (Addison disease) by assessing adrenal cortisol response.
Question 3: A 60-year-old man with type 2 diabetes has HbA1c of 8.9% on metformin monotherapy. He has CKD stage 3a (GFR 48 mL/min) and no cardiovascular disease. What is the best add-on therapy?
- Insulin glargine
- SGLT-2 inhibitor
- GLP-1 receptor agonist (Correct answer)
- Sulfonylurea
Correct answer: GLP-1 receptor agonist
GLP-1 receptor agonists have cardiovascular and renal benefits, are effective at all GFR levels (most agents), and reduce HbA1c significantly, making them preferred add-on therapy.
Question 4: A 35-year-old woman develops hypercalcemia with a PTH of 120 pg/mL (normal 10ā65). She is asymptomatic. Which statement is correct about management?
- Immediate parathyroidectomy is required
- Surgery is indicated if age <50 or serum calcium >1 mg/dL above upper limit (Correct answer)
- Only observation is appropriate for asymptomatic patients
- Start bisphosphonate therapy
Correct answer: Surgery is indicated if age <50 or serum calcium >1 mg/dL above upper limit
According to guidelines, parathyroidectomy is indicated in asymptomatic primary hyperparathyroidism if age <50, calcium >1 mg/dL above normal, T-score <ā2.5, or GFR <60 mL/min.
Question 5: A patient with type 2 diabetes has a foot ulcer that probes to bone. X-ray shows periosteal reaction and bone erosion. What is the most appropriate next step?
- Topical antibiotic therapy only
- Empiric oral antibiotics for 2 weeks
- MRI of the foot (Correct answer)
- Immediate surgical debridement
Correct answer: MRI of the foot
MRI is the gold standard for diagnosing diabetic osteomyelitis, offering high sensitivity and specificity for bone marrow involvement when plain X-rays are inconclusive.
Question 6: A 28-year-old woman presents with heat intolerance, tremor, weight loss, and a diffuse goiter with a bruit. TSH is undetectable. What is the most likely cause?
- Toxic multinodular goiter
- Graves disease (Correct answer)
- Subacute (de Quervain) thyroiditis
- Toxic adenoma
Correct answer: Graves disease
Graves disease is the most common cause of hyperthyroidism in young women and is characterized by diffuse goiter, thyroid bruit, and often extrathyroidal manifestations like ophthalmopathy.
ABIM Endocrinology 1
A 45-year-old woman presents with weight gain, fatigue, constipation, and cold intolerance.
TSH is 12 mIU/L and free T4 is low.
What is the most appropriate treatment?