What is the diagnostic 2-hour plasma glucose threshold during a 75-g OGTT for diabetes?

• A. ≥200 mg/dL
• B. ≥140 mg/dL
• C. ≥180 mg/dL
• D. ≥210 mg/dL

Answer: (A)

The important idea is that a 2-hour plasma glucose level of 200 mg/dL or higher after a 75-gram glucose drink is the diagnostic threshold for diabetes. After fasting, you drink 75 g of glucose, and a blood sugar measurement taken two hours later that reaches or exceeds 200 mg/dL indicates diabetes because the body is not handling the glucose load adequately.

Lower values define other states: 140–199 mg/dL after the 75 g test points to impaired glucose tolerance (a prediabetes category), while thresholds like 180 mg/dL or 210 mg/dL aren’t the official cutoffs for diagnosing diabetes with this test.