What OGTT level is considered diagnostic for diabetes?

The diagnostic criteria for diabetes using the Oral Glucose Tolerance Test (OGTT) is based on the level of glucose present two hours after consuming a glucose-rich beverage. A result of 200 mg/dl or higher is indicative of diabetes. This threshold is established because it shows that the body's ability to manage glucose is significantly impaired, suggesting diabetes mellitus.

In other contexts, results less than 140 mg/dl would indicate normal glucose metabolism, while a result ranging from 140 to 199 mg/dl is classified as "prediabetes," which signifies an increased risk for developing diabetes in the future but does not meet the diagnostic criteria for diabetes itself. Finally, a result between 100 and 125 mg/dl represents impaired fasting glucose rather than diabetes. Thus, only the level of 200 mg/dl or higher is considered diagnostic for diabetes according to established medical guidelines.