Which 2-hour glucose challenge result is classified as impaired glucose tolerance (IGT)?

Impaired glucose tolerance (IGT) is defined by specific blood glucose levels following a 2-hour oral glucose tolerance test (OGTT). According to the criteria set by the American Diabetes Association, a 2-hour plasma glucose level ranging from 140 to 199 mg/dL indicates IGT.

In this context, a result of 150 mg/dL falls squarely within this range, confirming the classification of IGT. This indicates that the body is not managing glucose levels effectively after the glucose challenge, which can lead to further risk of developing type 2 diabetes if not managed properly.

The other results—130 mg/dL is below the threshold for IGT, while 135 mg/dL is also considered normal. Meanwhile, a result of 204 mg/dL exceeds the upper limit for IGT and falls into the category of diabetes mellitus. Thus, 150 mg/dL is the only value that correctly aligns with the definition of impaired glucose tolerance.