ITE Endocrinology and Metabolism 5

Question 1

A 48-year-old woman with type 2 diabetes on metformin and linagliptin develops worsening renal function (eGFR now 22 mL/min). Which medication adjustment is most appropriate?

Accepted Answer

Discontinue metformin; continue linagliptin

Answer

Metformin is contraindicated when eGFR <30 mL/min; linagliptin, unlike other DPP-4 inhibitors, is primarily excreted via bile and requires no renal dose adjustment even in severe CKD.

Question 2

A 35-year-old man has hypertension, hypokalemia, and metabolic alkalosis. Plasma renin activity is markedly elevated, as is aldosterone. CT shows a 3 cm right renal artery mass. What is the most likely diagnosis?

Accepted Answer

Juxtaglomerular cell tumor (reninoma)

Answer

A juxtaglomerular cell tumor (reninoma) secretes renin autonomously, causing secondary hyperaldosteronism with high renin; in primary hyperaldosteronism, renin would be suppressed.

Question 3

A 68-year-old woman with osteoporosis and a T-score of −3.0 at the hip has been on denosumab for 3 years. She asks about stopping therapy. What is the most important risk to counsel her about?

Accepted Answer

Rapid bone loss and increased vertebral fracture risk upon discontinuation

Answer

Denosumab discontinuation causes a rebound increase in bone turnover markers and rapid bone loss, significantly increasing vertebral fracture risk; transition to a bisphosphonate is recommended before stopping.

Question 4

A 52-year-old man presents with increased hat and shoe size over 5 years, jaw prominence, and hyperhidrosis. Random GH is 12 ng/mL. What is the confirmatory test for acromegaly?

Accepted Answer

GH after oral glucose tolerance test (OGTT)

Answer

In acromegaly, GH fails to suppress to <1 ng/mL after 75 g oral glucose load (OGTT); this is the gold-standard confirmatory test because random GH levels fluctuate.

Question 5

A 29-year-old woman presents with weakness, hyperpigmentation, salt craving, and orthostatic hypotension. Labs show Na 128 mEq/L, K 5.8 mEq/L, and glucose 62 mg/dL. ACTH stimulation test shows a peak cortisol of 10 mcg/dL at 60 minutes. What is the most likely diagnosis?

Accepted Answer

Primary adrenal insufficiency (Addison's disease)

Answer

Primary adrenal insufficiency (Addison's disease) is characterized by loss of both cortisol and aldosterone, causing hyponatremia, hyperkalemia, hyperpigmentation (elevated ACTH), and a blunted cortisol response to ACTH stimulation.

ITE - Internal Medicine In-Training Exam Practice Test

ITE - Internal Medicine In-Training Exam Practice Test

ITE Endocrinology and Metabolism 5