Diabetes Mellitus USMLE Step 1 Practice Question
A 17-year-old boy with type 1 diabetes mellitus on insulin therapy presents with fasting morning glucose levels of 280 mg/dL. His endocrinologist requests 3 AM glucose checks, which consistently show levels of 60 mg/dL. Vital signs are stable: BP 118/76, HR 82, RR 16, temp 37°C, SpO2 98%. HbA1c is 9.2%. He denies nocturnal sweating or seizures. Which of the following best explains his morning hyperglycemia?
Answer choices
- ASomogyi effect due to nocturnal hypoglycemia triggering counterregulatory hormonesCorrect answer
- BProgressive beta cell failure from type 2 diabetes
- CInappropriate ADH secretion overnight
- DDawn phenomenon due to increased growth hormone without overnight hypoglycemia
- EExcess calcitonin secretion
- FNocturnal glucosuria from hyperglycemia during evening hours leading to osmotic diuresis and dehydration
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