An OGTT yields fasting serum glucose 124 mg/dL and 2-hour postload glucose 227 mg/dL. This result is diagnostic of which state?

An OGTT yields fasting serum glucose 124 mg/dL and 2-hour postload glucose 227 mg/dL. This result is diagnostic of which state?

• A. Normal
• B. Diabetes mellitus
• C. Addison disease
• D. Hyperinsulinism

Answer: (B)

The test shows how the body handles a glucose load, and diabetes is diagnosed when the 2-hour postload glucose is 200 mg/dL or higher. In this case, the fasting value is 124 mg/dL, which is not enough on its own to diagnose diabetes, but the 2-hour postload value is 227 mg/dL, well above the diabetes threshold. That single postload result confirms diabetes mellitus, regardless of the fasting value. Addison disease and hyperinsulinism don’t fit this pattern: Addison’s involves adrenal insufficiency with different clinical and laboratory features, and hyperinsulinism typically presents with inappropriate insulin responses and hypoglycemia, not a 2-hour glucose level above 200 mg/dL after a glucose load.

The test shows how the body handles a glucose load, and diabetes is diagnosed when the 2-hour postload glucose is 200 mg/dL or higher. In this case, the fasting value is 124 mg/dL, which is not enough on its own to diagnose diabetes, but the 2-hour postload value is 227 mg/dL, well above the diabetes threshold. That single postload result confirms diabetes mellitus, regardless of the fasting value. Addison disease and hyperinsulinism don’t fit this pattern: Addison’s involves adrenal insufficiency with different clinical and laboratory features, and hyperinsulinism typically presents with inappropriate insulin responses and hypoglycemia, not a 2-hour glucose level above 200 mg/dL after a glucose load.