Endocrinology for the BCPS exam: diabetes and beyond

Study cases written by our editors, not BPS items. The real BCPS exam is computer-based multiple choice, answered in order with no going back.

1. Case 01

   A 61-year-old woman with type 2 diabetes takes metformin 1,000 mg twice daily and glyburide 10 mg twice daily; A1c is 8.1% and eGFR is 74 mL/min/1.73 m². She has no ASCVD, HF, or CKD and is uninsured. She reports skipping meals near the end of each month when she runs out of food and has had two episodes of glucose below 60 mg/dL. Which change is most appropriate?

   1. AOption A: Replace glyburide with pioglitazone 15 mg daily
   2. BOption B: Add insulin glargine 10 units at bedtime
   3. COption C: Replace glyburide with glipizide 10 mg twice daily
   4. DOption D: Increase metformin to 1,000 mg three times daily

   Pick an option: the verdict and a note on every option open here.

   Best answer: A.

   Food insecurity makes insulin secretagogues and insulin dangerous, and ADA Standards advise choosing low-cost agents with minimal hypoglycemia risk; generic pioglitazone fits both and lowers A1c by about 1% in a patient without HF. Glipizide has less hypoglycemia than glyburide but is still a sulfonylurea that will cause lows on days she skips meals, and adding basal insulin raises that risk further. Metformin 3,000 mg/day exceeds the 2,550 mg/day maximum and adds little glycemic effect above 2,000 mg/day.

   A

   Correct: generic pioglitazone is low-cost, causes little hypoglycemia on its own, and lowers A1c in a patient without heart failure.

   B

   Basal insulin raises hypoglycemia risk on the days she skips meals and adds cost for an uninsured patient.

   C

   Glipizide causes fewer lows than glyburide, but it is still a sulfonylurea that will drop her glucose when meals are missed.

   D

   Metformin 3,000 mg/day exceeds the 2,550 mg/day maximum and adds little above 2,000 mg/day.

2. Case 02

   A 68-year-old woman has taken alendronate 70 mg weekly for 7 years. She has never had a fragility fracture, and repeat DXA shows stable T-scores of −2.1 at the lumbar spine and −1.8 at the femoral neck. She takes calcium and vitamin D and has no new risk factors. Which recommendation regarding alendronate is most appropriate?

   1. AOption A: Continue alendronate to complete 10 years of therapy
   2. BOption B: Stop alendronate; reassess risk in 2–3 years
   3. COption C: Switch alendronate to denosumab 60 mg every 6 months
   4. DOption D: Switch alendronate to teriparatide 20 mcg daily

   Pick an option: the verdict and a note on every option open here.

   Best answer: B.

   After 5 years of an oral bisphosphonate, a woman without prior fracture whose T-scores are now above −2.5 is at low-to-moderate risk and is a candidate for a drug holiday, because alendronate persists in bone and longer use increases atypical femur fracture and osteonecrosis risk. Continuing to 10 years is reserved for high-risk patients, such as those with a prior vertebral fracture or a hip T-score of −2.5 or lower. Denosumab and teriparatide are for higher-risk or failing patients, and denosumab would create a new need for follow-on therapy because of rebound fractures when it is stopped.

   A

   Ten years is reserved for higher-risk patients, such as those with a prior vertebral fracture or a hip T-score of −2.5 or lower.

   B

   Correct: after 5 or more years with no fracture and T-scores above −2.5, a drug holiday with periodic reassessment fits.

   C

   Denosumab is for higher risk, and stopping it later causes rebound fractures, creating a need for follow-on therapy.

   D

   Teriparatide is an anabolic for very high risk or treatment failure, and neither applies here.

3. Case 03

   A 55-year-old man with type 2 diabetes takes metformin 1,000 mg twice daily and glipizide 10 mg twice daily (A1c 7.6%). He recently began brisk 45-minute walks each afternoon and twice felt shaky and sweaty afterward, with glucose of 62 mg/dL. He wants to keep exercising. Which recommendation is most appropriate?

   1. AOption A: Check glucose before walks; eat 15 g carbs if <90 mg/dL
   2. BOption B: Take an extra glipizide dose before each afternoon walk
   3. COption C: Walk before breakfast while fasting instead of afternoons
   4. DOption D: Stop walking until his A1c is below 7%

   Pick an option: the verdict and a note on every option open here.

   Best answer: A.

   Exercise increases insulin sensitivity, and with a sulfonylurea that can cause hypoglycemia; ADA advises checking glucose before activity and taking carbohydrate when it is below about 90 mg/dL (and reviewing the glipizide dose if lows recur). An extra glipizide dose before exercise makes hypoglycemia more likely. Stopping exercise abandons an effective treatment, and walking while fasting on a sulfonylurea increases the risk of lows.

   A

   Correct: checking glucose before walks and taking carbohydrate below about 90 mg/dL lets him keep exercising safely on a sulfonylurea.

   B

   An extra glipizide dose adds insulin secretion just as activity raises insulin sensitivity, inviting more lows.

   C

   Fasting exercise on a sulfonylurea increases the risk of hypoglycemia rather than lowering it.

   D

   Stopping exercise abandons an effective therapy and is not needed when the lows can be prevented.

4. Case 04

   A 49-year-old asymptomatic man has a fasting plasma glucose of 131 mg/dL and an A1c of 6.8%, both measured from the same blood sample at a routine visit. He has no history of diabetes. Which interpretation is correct according to ADA Standards of Care?

   1. AOption A: Prediabetes; repeat testing in 1 year
   2. BOption B: Type 2 diabetes is confirmed by these results
   3. COption C: Repeat the A1c in 3 months to confirm
   4. DOption D: An oral glucose tolerance test is required to confirm

   Pick an option: the verdict and a note on every option open here.

   Best answer: B.

   ADA diagnostic criteria are FPG ≥126 mg/dL or A1c ≥6.5%, and in an asymptomatic person two abnormal results are needed—these may be two different tests from the same sample, so both values here confirm diabetes. Repeating the A1c is needed only when a single test is abnormal or the two tests are discordant. An OGTT is not required, and both values exceed the prediabetes ranges (FPG 100–125, A1c 5.7–6.4%).

   A

   Both values are in the diabetes range, above the prediabetes cutoffs of FPG 100–125 mg/dL and A1c 5.7–6.4%.

   B

   Correct: two different abnormal tests, even from the same sample, confirm diabetes in an asymptomatic person.

   C

   Repeating the A1c is needed only when a single test is abnormal or the two tests disagree.

   D

   An oral glucose tolerance test is not required when two concordant tests already meet the criteria.

5. Case 05

   A 79-year-old woman in assisted living has type 2 diabetes, stage 3b CKD, heart failure, mild-to-moderate dementia, and two falls this year. She takes insulin glargine 18 units daily. A1c is 6.4%, and staff document glucose below 70 mg/dL three times a week. Which A1c goal and action are most appropriate?

   1. AOption A: Goal <8.0%; reduce the daily glargine dose
   2. BOption B: Goal <6.5%; continue the current dose
   3. COption C: Goal <7.0%; continue the current dose
   4. DOption D: Goal <7.0%; add a sulfonylurea at breakfast

   Pick an option: the verdict and a note on every option open here.

   Best answer: A.

   ADA 2026 sets a less stringent A1c goal (<8.0%) for older adults with multiple chronic illnesses or cognitive impairment, and her frequent hypoglycemia with falls means she is overtreated, so insulin should be reduced. A goal of <6.5% or <7.0% is appropriate only for healthy older adults with low hypoglycemia risk. Adding a sulfonylurea worsens hypoglycemia and is on the Beers list to avoid.

   A

   Correct: with complex illness, dementia and recurrent lows, a goal below 8.0% applies and her insulin should be reduced.

   B

   A goal below 6.5% fits only healthy adults at low hypoglycemia risk, and her current dose is already causing lows.

   C

   A goal below 7.0% is too strict for an older adult with dementia and falls, and keeping the dose keeps the hypoglycemia going.

   D

   Adding a sulfonylurea worsens hypoglycemia and is on the Beers list to avoid in older adults.

6. Case 06

   A 45-year-old woman with type 1 diabetes uses CGM and multiple daily injections: insulin glargine U-100 22 units at bedtime and insulin aspart with meals. Her A1c is 8.2%, and CGM shows time below 70 mg/dL of 9%, mostly between midnight and 4 AM, with daytime hyperglycemia after meals. Which basal insulin change is most appropriate to reduce hypoglycemia?

   1. AOption A: Move glargine U-100 to morning dosing
   2. BOption B: Switch to NPH insulin twice daily
   3. COption C: Switch to regular insulin at bedtime
   4. DOption D: Switch to insulin degludec once daily

   Pick an option: the verdict and a note on every option open here.

   Best answer: D.

   Insulin degludec has a flat, ultra-long profile (half-life about 25 hours) and in SWITCH 1 reduced nocturnal and severe hypoglycemia compared with glargine U-100 in type 1 diabetes; her time below 70 mg/dL of 9% exceeds the target of less than 4%. Moving glargine to the morning does not change total basal exposure or its day-to-day variability. NPH has a peak 4–10 hours after dosing that increases overnight lows, and bedtime regular insulin peaks overnight and would worsen them.

   A

   Moving glargine to the morning does not change total basal exposure or its day-to-day variability.

   B

   NPH peaks 4–10 hours after a dose, which tends to increase overnight lows.

   C

   Bedtime regular insulin would peak overnight and worsen the nocturnal hypoglycemia.

   D

   Correct: degludec’s flat ultra-long profile reduced nocturnal and severe hypoglycemia versus glargine U-100 in SWITCH 1.

7. Case 07

   A 35-year-old woman with primary adrenal insufficiency takes hydrocortisone 15 mg each morning and 5 mg in the early afternoon plus fludrocortisone 0.1 mg daily. She calls the clinic with influenza: temperature 38.6°C, myalgias, and she is drinking fluids and keeping down oral medications without vomiting. Which recommendation is most appropriate?

   1. AOption A: Give hydrocortisone 100 mg IM now and go to the ED
   2. BOption B: Continue the usual hydrocortisone and fludrocortisone doses
   3. COption C: Double hydrocortisone while febrile; keep fludrocortisone
   4. DOption D: Double fludrocortisone while febrile; keep hydrocortisone

   Pick an option: the verdict and a note on every option open here.

   Best answer: C.

   Sick-day rules for adrenal insufficiency call for doubling the glucocorticoid dose during fever above 38°C (tripling above 39°C) until recovery, while the mineralocorticoid dose stays the same. Continuing the usual doses risks adrenal crisis because cortisol demand rises with illness. Fludrocortisone does not provide stress glucocorticoid coverage, and parenteral hydrocortisone 100 mg is reserved for vomiting, inability to take oral medicine, or signs of adrenal crisis, none of which she has.

   A

   Parenteral hydrocortisone 100 mg is for vomiting, inability to take oral drugs or adrenal crisis, and she has none of these.

   B

   Usual doses risk adrenal crisis because cortisol demand rises with febrile illness.

   C

   Correct: sick-day rules double the glucocorticoid during fever over 38°C while the fludrocortisone dose stays the same.

   D

   Fludrocortisone is a mineralocorticoid and provides no stress glucocorticoid coverage, so doubling it misses the point.

8. Case 08

   A 58-year-old postmenopausal woman with primary hypothyroidism has taken levothyroxine 112 mcg daily for 5 years. She is asymptomatic and takes it correctly on an empty stomach. Labs: TSH 0.2 mIU/L, free T4 1.6 ng/dL (upper end of normal). She has no history of thyroid cancer. Which is the most appropriate management?

   1. AOption A: Decrease levothyroxine to 100 mcg daily
   2. BOption B: Hold levothyroxine for 1 week, then restart 88 mcg daily
   3. COption C: Continue 112 mcg daily and recheck TSH in 6 months
   4. DOption D: Decrease levothyroxine to 75 mcg daily

   Pick an option: the verdict and a note on every option open here.

   Best answer: A.

   A suppressed TSH on replacement therapy means overreplacement, which in a postmenopausal woman raises atrial fibrillation and bone loss risk, so the dose should be reduced by about 12.5 mcg (one strength step) with TSH rechecked in 6–8 weeks. Continuing the dose because she feels well ignores those risks of iatrogenic subclinical hyperthyroidism. A cut to 75 mcg or holding the drug overshoots and risks hypothyroidism, because free T4 is still within the normal range.

   A

   Correct: a suppressed TSH means overreplacement, so one strength step down to 100 mcg with a TSH recheck in 6–8 weeks fits.

   B

   A one-week hold followed by a large cut overshoots when free T4 is still within the normal range.

   C

   Continuing because she feels well ignores the atrial fibrillation and bone-loss risk of iatrogenic subclinical hyperthyroidism.

   D

   A cut to 75 mcg is too large and risks swinging her into hypothyroidism.

9. Case 09

   A 66-year-old woman with type 2 diabetes and osteoporosis (prior vertebral compression fracture, on alendronate) takes metformin 1,000 mg twice daily. A1c is 8.1%, BMI 31 kg/m², eGFR 72 mL/min/1.73 m², and she has no ASCVD, HF or CKD. She lives alone and has fallen once this year. Which medication is most appropriate to add?

   1. AOption A: Semaglutide 0.25 mg SC once weekly
   2. BOption B: Canagliflozin 100 mg orally once daily
   3. COption C: Glipizide 5 mg orally once daily
   4. DOption D: Pioglitazone 15 mg orally once daily

   Pick an option: the verdict and a note on every option open here.

   Best answer: A.

   Semaglutide lowers A1c and weight without hypoglycemia or a fracture signal, which suits an obese patient with osteoporosis and falls. Pioglitazone reduces bone formation and increases fractures in women, and canagliflozin carries a labeled fracture warning, so another agent is preferred when fracture risk is high. Glipizide causes hypoglycemia, which raises fall risk, and the Beers criteria advise avoiding sulfonylureas in older adults.

   A

   Correct: semaglutide lowers A1c and weight without hypoglycemia or a fracture signal, which suits osteoporosis and falls.

   B

   Canagliflozin carries a labeled fracture warning, a poor fit after a vertebral fracture.

   C

   Glipizide can cause hypoglycemia, which raises fall risk in a woman who lives alone and has already fallen.

   D

   Pioglitazone reduces bone formation and increases fractures in women, so it is a poor choice with osteoporosis.

10. Case 10

    A 35-year-old man with acromegaly underwent transsphenoidal surgery 4 months ago. A residual tumor invades the cavernous sinus and is not resectable. IGF-1 is 2.6 times the upper limit of normal, and he has no diabetes or gallbladder disease. Which medication is most appropriate to start?

    1. AOption A: Bromocriptine 2.5 mg orally three times daily
    2. BOption B: Pegvisomant 10 mg SC once daily
    3. COption C: Octreotide LAR 20 mg IM every 4 weeks
    4. DOption D: Cabergoline 0.5 mg orally once weekly

    Pick an option: the verdict and a note on every option open here.

    Best answer: C.

    A long-acting somatostatin receptor ligand (octreotide LAR or lanreotide) is first-line medical therapy for persistent acromegaly after surgery; it lowers GH and IGF-1 and can shrink residual tumor. Cabergoline is reserved for modest IGF-1 elevation (under about 2 times the upper limit of normal), and bromocriptine is even less effective. Pegvisomant normalizes IGF-1 by blocking the GH receptor but does not shrink the tumor, so it is second-line after somatostatin ligand failure or intolerance.

    A

    Bromocriptine is even less effective than cabergoline in acromegaly and is not a first-line option.

    B

    Pegvisomant normalizes IGF-1 but does not shrink tumor, so it is second-line after a somatostatin ligand fails.

    C

    Correct: a long-acting somatostatin receptor ligand is first-line medical therapy for persistent acromegaly after surgery.

    D

    Cabergoline suits only a modest IGF-1 elevation, and his level is 2.6 times the upper limit.

11. Case 11

    A 54-year-old man with type 2 diabetes plans to fast from dawn to sunset during Ramadan. He takes metformin 1,000 mg twice daily and glimepiride 4 mg every morning with breakfast. A1c is 7.4%, eGFR is 80 mL/min/1.73 m², and he has had no hypoglycemia. He wants to fast safely. Which adjustment is most appropriate?

    1. AOption A: Continue glimepiride 4 mg each morning as usual
    2. BOption B: Move glimepiride to sunset at a lower dose
    3. COption C: Take both drugs together with the predawn meal
    4. DOption D: Stop metformin for the whole month of fasting

    Pick an option: the verdict and a note on every option open here.

    Best answer: B.

    Respecting his religious practice means adapting the regimen: IDF-DAR guidance moves a once-daily sulfonylurea to the sunset meal (iftar) and reduces the dose, while twice-daily metformin is simply taken with iftar and the predawn meal (suhoor). Keeping glimepiride in the morning, or taking it at suhoor, puts its peak effect in the fasting hours and invites hypoglycemia. Metformin rarely causes hypoglycemia, so stopping it only worsens control.

    A

    Morning glimepiride places its peak effect in the fasting hours and invites hypoglycemia.

    B

    Correct: Ramadan guidance moves a once-daily sulfonylurea to the sunset meal at a reduced dose.

    C

    Taking glimepiride at the predawn meal still spreads its action across the day-long fast.

    D

    Metformin rarely causes hypoglycemia, so stopping it only worsens control; it is simply split between the two meals.

12. Case 12

    A 62-year-old postmenopausal woman is starting prednisone 15 mg daily, expected to continue for at least 6 months for polymyalgia rheumatica. DXA shows a femoral neck T-score of −2.0, and her glucocorticoid-adjusted FRAX 10-year risk of major osteoporotic fracture is 22%. CrCl is 70 mL/min, and she has no esophageal disease. Which plan is most appropriate?

    1. AOption A: Start alendronate with calcium and vitamin D
    2. BOption B: Start raloxifene 60 mg daily with calcium and vitamin D
    3. COption C: Calcium and vitamin D alone; repeat DXA in 2 years
    4. DOption D: Start teriparatide 20 mcg SC daily with calcium

    Pick an option: the verdict and a note on every option open here.

    Best answer: A.

    Her adjusted FRAX of at least 20% for major fracture places her at high risk under the ACR 2022 glucocorticoid-induced osteoporosis guideline, for which an oral bisphosphonate plus calcium and vitamin D is the preferred first choice. Calcium and vitamin D alone are insufficient at high risk with prolonged glucocorticoid use. Raloxifene is reserved for when no other option is suitable, and teriparatide is for very high risk (e.g., prior fracture or very low BMD).

    A

    Correct: an adjusted FRAX of 20% or more is high risk, and an oral bisphosphonate with calcium and vitamin D is the preferred start.

    B

    Raloxifene is kept for when no other option suits, which is not the case for this patient.

    C

    Calcium and vitamin D alone are not enough at high risk with months of prednisone ahead.

    D

    Teriparatide is for very high risk, such as a prior fracture or very low BMD, which she does not have.

13. Case 13

    A 24-year-old man with type 1 diabetes uses insulin glargine and insulin lispro. His insulin-to-carbohydrate ratio is 1 unit per 12 g, and his correction factor is 1 unit per 40 mg/dL above a target of 120 mg/dL. Before lunch his glucose is 200 mg/dL, and he plans to eat 60 g of carbohydrate. How many units of lispro should he inject?

    1. AOption A: 5 units
    2. BOption B: 2 units
    3. COption C: 7 units
    4. DOption D: 10 units

    Pick an option: the verdict and a note on every option open here.

    Best answer: C.

    Meal dose = 60 g ÷ 12 g/unit = 5 units; correction dose = (200 − 120) ÷ 40 = 2 units; total = 7 units. Five units covers the carbohydrate but ignores the high pre-meal glucose, and 2 units is the correction alone. Ten units comes from dividing the entire glucose of 200 by 40 instead of only the amount above target, which would risk hypoglycemia.

    A

    Five units covers the 60 g of carbohydrate but ignores a glucose 80 mg/dL above target.

    B

    Two units is the correction dose alone and leaves the meal uncovered.

    C

    Correct: 60 ÷ 12 gives 5 units for the meal and (200 − 120) ÷ 40 gives 2 for correction, 7 units in all.

    D

    Ten units comes from dividing the whole 200 mg/dL by 40 instead of only the excess above target.

14. Case 14

    A 40-year-old woman with type 1 diabetes and Hashimoto thyroiditis reports more frequent hypoglycemia over 2 months despite unchanged insulin doses, diet and activity. She also has fatigue, a 4-kg weight loss, salt craving and darker skin creases. Labs: Na 131 mEq/L, K 5.3 mEq/L, TSH 2.1 mIU/L on levothyroxine 100 mcg daily, A1c 6.4%. Which is the most appropriate next step?

    1. AOption A: Reduce basal insulin by 20% and recheck CGM
    2. BOption B: Switch glargine to insulin degludec
    3. COption C: Check morning serum cortisol and ACTH
    4. DOption D: Increase levothyroxine to 112 mcg daily

    Pick an option: the verdict and a note on every option open here.

    Best answer: C.

    Falling insulin requirements with hyponatremia, hyperkalemia, weight loss and hyperpigmentation in a patient with two autoimmune endocrine diseases suggest primary adrenal insufficiency (autoimmune polyglandular syndrome type 2), so morning cortisol and ACTH (then a cosyntropin test) are needed before anything else. Reducing basal insulin treats the symptom but misses a potentially fatal diagnosis. Her TSH is normal, so the thyroid dose is not the cause, and changing basal insulin type does not address the reason for the hypoglycemia.

    A

    Cutting basal insulin treats the lows but misses a potentially fatal diagnosis behind them.

    B

    Changing the basal insulin type does nothing about the reason her insulin needs have fallen.

    C

    Correct: hyponatremia, hyperkalemia, weight loss and darker creases with two autoimmune diseases point to adrenal insufficiency.

    D

    Her TSH is normal on the current dose, so levothyroxine is not the cause.

15. Case 15

    A 35-year-old woman (not pregnant) with untreated Graves disease presents in thyroid storm: temperature 40.1°C, HR 148 beats/minute in sinus rhythm, agitation, and a Burch-Wartofsky score of 55. Propranolol and hydrocortisone have been started. Which antithyroid plan is most appropriate?

    1. AOption A: Methimazole 20 mg and potassium iodide given together
    2. BOption B: Potassium iodide now, then PTU 1 hour later
    3. COption C: Radioactive iodine ablation once she is stable today
    4. DOption D: PTU 500 mg load, then potassium iodide 1 hour later

    Pick an option: the verdict and a note on every option open here.

    Best answer: D.

    In thyroid storm a thionamide is given first to block new hormone synthesis, and iodine is given at least 1 hour later to stop release of preformed hormone; PTU is preferred because it also inhibits peripheral conversion of T4 to T3. Giving iodine first is the classic sequencing error, because it supplies substrate for more hormone synthesis. Giving both at the same moment risks the same problem, and radioactive iodine has no place in the acute storm and can worsen thyrotoxicosis.

    A

    Giving iodine at the same moment as the thionamide risks fueling new hormone synthesis before it is blocked.

    B

    Iodine before a thionamide is the classic sequencing error, supplying substrate for more hormone.

    C

    Radioactive iodine has no place in acute storm and can worsen thyrotoxicosis.

    D

    Correct: PTU first blocks synthesis and T4-to-T3 conversion, and iodine follows at least an hour later to halt release.