Which of the following findings does not confirm a diagnosis of diabetes?

The key to determining which finding does not confirm a diagnosis of diabetes lies in understanding the diagnostic criteria established by organizations such as the American Diabetes Association (ADA). A random plasma glucose level of 198 mg/dL is an important value because, while it is elevated and can suggest diabetes, it is not definitive on its own.

For diagnosis, the random glucose test must be interpreted in conjunction with symptoms. If a patient is exhibiting classic hyperglycemic symptoms (such as polyuria, polydipsia, and unexplained weight loss), a random glucose of 198 mg/dL could indeed support a diabetes diagnosis. However, without these symptoms, a random glucose test alone does not necessarily confirm diabetes—it may warrant further evaluation.

On the other hand, a glycated hemoglobin (A1C) level of 7.0% is a criterion that directly indicates the presence of diabetes, as it meets the threshold set for diagnostic purposes. Similarly, a fasting glucose of 155 mg/dL exceeds the diagnostic cut-off and confirms diabetes. Lastly, an oral glucose tolerance test (OGTT) results in a plasma glucose of 250 mg/dL, which also surpasses the established threshold for diabetes diagnosis.

Thus, while the random glucose of