Which of the following criteria is used to diagnose type 1 and type 2 diabetes?

The diagnosis of type 1 and type 2 diabetes incorporates several critical criteria, and one of the key benchmarks is the fasting plasma glucose (FPG) level. An FPG of 126 mg/dL or greater is one of the established diagnostic thresholds for diabetes.

This criterion is significant because it reflects the body's ability to regulate blood glucose levels after a period of fasting, indicating insulin resistance or inadequate insulin secretion. For diagnosing diabetes, the FPG test is typically preferred due to its straightforward administration and reliability as a marker of glucose metabolism dysfunction.

While other criteria, such as the HbA1c and the results from an oral glucose tolerance test (OGTT), are also valid and used in clinical practice for diagnosing diabetes, the FPG level is explicitly defined and standardized for diagnosis by guidelines set forth by diabetes associations.

Therefore, the FPG cutoff of 126 mg/dL serves as a foundational indicator for determining the presence of diabetes, making this criterion essential in the diagnostic process.