American Board of Internal Medicine
(ABIM) Endocrinology, Diabetes and
Metabolism Certification Examination
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. A 52-year-old woman with a 10-year history of type 2 diabetes presents
with progressive numbness and burning pain in her feet. She has had two
episodes of cellulitis in the past year. Her HbA1c is 8.9% on metformin 2000
mg daily and glipizide 20 mg daily. Examination reveals diminished vibratory
sensation and absent ankle reflexes. Which of the following is the most
appropriate next step in managing her neuropathic pain?
A. Add pregabalin 75 mg three times daily
B. Increase glipizide to 30 mg daily
C. Initiate duloxetine 60 mg once daily
D. Prescribe topical capsaicin 0.075% cream
Answer: C
Rationale: Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI) that
is FDA-approved for diabetic peripheral neuropathy and is considered first-line
therapy for neuropathic pain in patients with diabetes, along with pregabalin or
gabapentin. However, pregabalin requires dose titration and renal adjustment.
Given the patient's chronic pain and need for a proven agent with a fixed starting
dose, duloxetine 60 mg daily is the preferred initial choice. Topical capsaicin is a
secondary option, and increasing sulfonylurea does not address neuropathy. The
correct answer emphasizes evidence-based first-line pharmacotherapy for painful
diabetic neuropathy.
, 2. A 45-year-old man is found to have a fasting plasma glucose of 128 mg/dL
on routine screening. He has a BMI of 34 kg/m² and a family history of
diabetes. He has no symptoms. A repeat fasting glucose is 131 mg/dL. His
HbA1c is 6.3%. Which of the following best characterizes his glycemic
status?
A. Impaired fasting glucose
B. Impaired fasting glucose and impaired glucose tolerance
C. Type 2 diabetes mellitus
D. Normal glucose tolerance
Answer: C
Rationale: According to the American Diabetes Association (ADA) criteria, diabetes
is diagnosed by a fasting plasma glucose ≥126 mg/dL, a 2-hour plasma glucose
≥200 mg/dL during an OGTT, an HbA1c ≥6.5%, or a random glucose ≥200 mg/dL
with symptoms. This patient has a confirmed fasting glucose >126 mg/dL on two
occasions and an HbA1c of 6.3% (which is below the diabetes threshold but does
not negate the fasting glucose diagnosis). The fasting glucose alone meets criteria
for diabetes, so the correct classification is type 2 diabetes mellitus, not just
impaired fasting glucose (which is 100-125 mg/dL).
3. A 28-year-old woman presents with palpitations, weight loss, and heat
intolerance. Her thyroid-stimulating hormone (TSH) is <0.01 mIU/L, and free
T4 is 3.2 ng/dL (normal 0.8-1.8). Radioiodine uptake is 2% at 24 hours. She
has a normal serum thyroglobulin level. Which of the following is the most
likely diagnosis?
A. Graves' disease
B. Toxic multinodular goiter
C. Subacute thyroiditis
D. Factitious thyrotoxicosis
Answer: C
Rationale: The combination of hyperthyroidism with a very low radioactive iodine
uptake (RAIU) indicates thyroiditis or exogenous thyroid hormone. Subacute
thyroiditis (de Quervain's) typically presents with a painful, tender thyroid,
,elevated ESR, and low RAIU due to release of preformed hormones from glandular
destruction. Graves' disease and toxic multinodular goiter would show high RAIU.
Factitious thyrotoxicosis would have a suppressed thyroglobulin level, whereas this
patient has a normal thyroglobulin, making subacute thyroiditis more likely.
4. A 60-year-old man with type 2 diabetes on insulin glargine 40 units daily
and aspart insulin with meals has a history of recurrent hypoglycemia,
especially at night. His HbA1c is 6.9%. He reports waking with sweats and
confusion. Continuous glucose monitoring shows a prolonged nadir
between 2:00 AM and 4:00 AM. Which of the following adjustments is most
appropriate?
A. Increase evening insulin glargine dose
B. Move the insulin glargine injection to morning
C. Add a bedtime snack of complex carbohydrates
D. Reduce the aspart insulin dose at dinner
Answer: B
Rationale: Nocturnal hypoglycemia in patients on basal insulin can be managed by
adjusting the timing or dose of the basal insulin. Moving the basal insulin
(glargine) to the morning can help shift the peak action to daytime, reducing the
risk of overnight hypoglycemia. Increasing the dose would worsen the problem.
Adding a bedtime snack may help but is less effective than optimizing basal
timing. Reducing prandial insulin may be considered if the hypoglycemia is related
to dinner, but the pattern suggests a basal issue. Morning administration of
glargine is a validated strategy to reduce nocturnal hypoglycemia.
5. A 35-year-old woman is evaluated for secondary amenorrhea. She has
galactorrhea and bitemporal hemianopia on visual field testing. Her
prolactin level is 350 ng/mL (normal <25). MRI reveals a 1.8 cm pituitary
macroadenoma. She desires pregnancy. Which of the following is the most
appropriate initial treatment?
A. Transsphenoidal surgical resection
B. Cabergoline 0.5 mg twice weekly
, C. Bromocriptine 2.5 mg twice daily
D. Radiation therapy
Answer: B
Rationale: For prolactin-secreting macroadenomas with visual field defects,
medical therapy with dopamine agonists is first-line, even for large tumors, as they
shrink the adenoma and lower prolactin. Cabergoline is preferred over
bromocriptine due to better efficacy, tolerability, and once- or twice-weekly dosing.
Surgery is reserved for those who fail or cannot tolerate medical therapy, or for
apoplexy. This patient's visual field defect is likely reversible with dopamine
agonist therapy, and cabergoline is safe in pregnancy once pregnancy is
confirmed.
6. A 55-year-old man presents with generalized weakness, fatigue, and
hyperpigmentation of his skin and oral mucosa. His blood pressure is 90/60
mmHg with orthostatic symptoms. Laboratory tests reveal hyponatremia,
hyperkalemia, and elevated ACTH. A cosyntropin stimulation test shows a
peak cortisol of 8 µg/dL (normal >18). Which of the following is the most
appropriate diagnosis?
A. Secondary adrenal insufficiency
B. Primary adrenal insufficiency (Addison's disease)
C. Cushing's syndrome
D. Congenital adrenal hyperplasia
Answer: B
Rationale: This patient has classic features of primary adrenal insufficiency:
hyperpigmentation (due to elevated ACTH), orthostatic hypotension,
hyponatremia, and hyperkalemia. The cosyntropin stimulation test shows an
inadequate cortisol response, confirming adrenal failure. Elevated ACTH confirms
the etiology is adrenal (primary) rather than pituitary (secondary). Secondary
adrenal insufficiency would show low or normal ACTH and normal pigmentation.
This presentation is classic for Addison's disease.
7. A 48-year-old woman with a history of Hashimoto's thyroiditis is on
levothyroxine 100 µg daily. She presents with palpitations, anxiety, and
(ABIM) Endocrinology, Diabetes and
Metabolism Certification Examination
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. A 52-year-old woman with a 10-year history of type 2 diabetes presents
with progressive numbness and burning pain in her feet. She has had two
episodes of cellulitis in the past year. Her HbA1c is 8.9% on metformin 2000
mg daily and glipizide 20 mg daily. Examination reveals diminished vibratory
sensation and absent ankle reflexes. Which of the following is the most
appropriate next step in managing her neuropathic pain?
A. Add pregabalin 75 mg three times daily
B. Increase glipizide to 30 mg daily
C. Initiate duloxetine 60 mg once daily
D. Prescribe topical capsaicin 0.075% cream
Answer: C
Rationale: Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI) that
is FDA-approved for diabetic peripheral neuropathy and is considered first-line
therapy for neuropathic pain in patients with diabetes, along with pregabalin or
gabapentin. However, pregabalin requires dose titration and renal adjustment.
Given the patient's chronic pain and need for a proven agent with a fixed starting
dose, duloxetine 60 mg daily is the preferred initial choice. Topical capsaicin is a
secondary option, and increasing sulfonylurea does not address neuropathy. The
correct answer emphasizes evidence-based first-line pharmacotherapy for painful
diabetic neuropathy.
, 2. A 45-year-old man is found to have a fasting plasma glucose of 128 mg/dL
on routine screening. He has a BMI of 34 kg/m² and a family history of
diabetes. He has no symptoms. A repeat fasting glucose is 131 mg/dL. His
HbA1c is 6.3%. Which of the following best characterizes his glycemic
status?
A. Impaired fasting glucose
B. Impaired fasting glucose and impaired glucose tolerance
C. Type 2 diabetes mellitus
D. Normal glucose tolerance
Answer: C
Rationale: According to the American Diabetes Association (ADA) criteria, diabetes
is diagnosed by a fasting plasma glucose ≥126 mg/dL, a 2-hour plasma glucose
≥200 mg/dL during an OGTT, an HbA1c ≥6.5%, or a random glucose ≥200 mg/dL
with symptoms. This patient has a confirmed fasting glucose >126 mg/dL on two
occasions and an HbA1c of 6.3% (which is below the diabetes threshold but does
not negate the fasting glucose diagnosis). The fasting glucose alone meets criteria
for diabetes, so the correct classification is type 2 diabetes mellitus, not just
impaired fasting glucose (which is 100-125 mg/dL).
3. A 28-year-old woman presents with palpitations, weight loss, and heat
intolerance. Her thyroid-stimulating hormone (TSH) is <0.01 mIU/L, and free
T4 is 3.2 ng/dL (normal 0.8-1.8). Radioiodine uptake is 2% at 24 hours. She
has a normal serum thyroglobulin level. Which of the following is the most
likely diagnosis?
A. Graves' disease
B. Toxic multinodular goiter
C. Subacute thyroiditis
D. Factitious thyrotoxicosis
Answer: C
Rationale: The combination of hyperthyroidism with a very low radioactive iodine
uptake (RAIU) indicates thyroiditis or exogenous thyroid hormone. Subacute
thyroiditis (de Quervain's) typically presents with a painful, tender thyroid,
,elevated ESR, and low RAIU due to release of preformed hormones from glandular
destruction. Graves' disease and toxic multinodular goiter would show high RAIU.
Factitious thyrotoxicosis would have a suppressed thyroglobulin level, whereas this
patient has a normal thyroglobulin, making subacute thyroiditis more likely.
4. A 60-year-old man with type 2 diabetes on insulin glargine 40 units daily
and aspart insulin with meals has a history of recurrent hypoglycemia,
especially at night. His HbA1c is 6.9%. He reports waking with sweats and
confusion. Continuous glucose monitoring shows a prolonged nadir
between 2:00 AM and 4:00 AM. Which of the following adjustments is most
appropriate?
A. Increase evening insulin glargine dose
B. Move the insulin glargine injection to morning
C. Add a bedtime snack of complex carbohydrates
D. Reduce the aspart insulin dose at dinner
Answer: B
Rationale: Nocturnal hypoglycemia in patients on basal insulin can be managed by
adjusting the timing or dose of the basal insulin. Moving the basal insulin
(glargine) to the morning can help shift the peak action to daytime, reducing the
risk of overnight hypoglycemia. Increasing the dose would worsen the problem.
Adding a bedtime snack may help but is less effective than optimizing basal
timing. Reducing prandial insulin may be considered if the hypoglycemia is related
to dinner, but the pattern suggests a basal issue. Morning administration of
glargine is a validated strategy to reduce nocturnal hypoglycemia.
5. A 35-year-old woman is evaluated for secondary amenorrhea. She has
galactorrhea and bitemporal hemianopia on visual field testing. Her
prolactin level is 350 ng/mL (normal <25). MRI reveals a 1.8 cm pituitary
macroadenoma. She desires pregnancy. Which of the following is the most
appropriate initial treatment?
A. Transsphenoidal surgical resection
B. Cabergoline 0.5 mg twice weekly
, C. Bromocriptine 2.5 mg twice daily
D. Radiation therapy
Answer: B
Rationale: For prolactin-secreting macroadenomas with visual field defects,
medical therapy with dopamine agonists is first-line, even for large tumors, as they
shrink the adenoma and lower prolactin. Cabergoline is preferred over
bromocriptine due to better efficacy, tolerability, and once- or twice-weekly dosing.
Surgery is reserved for those who fail or cannot tolerate medical therapy, or for
apoplexy. This patient's visual field defect is likely reversible with dopamine
agonist therapy, and cabergoline is safe in pregnancy once pregnancy is
confirmed.
6. A 55-year-old man presents with generalized weakness, fatigue, and
hyperpigmentation of his skin and oral mucosa. His blood pressure is 90/60
mmHg with orthostatic symptoms. Laboratory tests reveal hyponatremia,
hyperkalemia, and elevated ACTH. A cosyntropin stimulation test shows a
peak cortisol of 8 µg/dL (normal >18). Which of the following is the most
appropriate diagnosis?
A. Secondary adrenal insufficiency
B. Primary adrenal insufficiency (Addison's disease)
C. Cushing's syndrome
D. Congenital adrenal hyperplasia
Answer: B
Rationale: This patient has classic features of primary adrenal insufficiency:
hyperpigmentation (due to elevated ACTH), orthostatic hypotension,
hyponatremia, and hyperkalemia. The cosyntropin stimulation test shows an
inadequate cortisol response, confirming adrenal failure. Elevated ACTH confirms
the etiology is adrenal (primary) rather than pituitary (secondary). Secondary
adrenal insufficiency would show low or normal ACTH and normal pigmentation.
This presentation is classic for Addison's disease.
7. A 48-year-old woman with a history of Hashimoto's thyroiditis is on
levothyroxine 100 µg daily. She presents with palpitations, anxiety, and
