What is the definition of impaired glucose tolerance?

Impaired glucose tolerance is characterized specifically by a serum glucose level that falls between 140 and 200 mg/dL when measured 2 hours after a standard 75 g oral glucose tolerance test. This definition is critical because it helps identify individuals who are at increased risk for developing type 2 diabetes and cardiovascular disease. The glucose levels during this test indicate that the body is not effectively processing glucose, which can lead to various metabolic disturbances.

The thresholds for glucose levels identified in other choices do not align with the standardized definition of impaired glucose tolerance. For instance, a 1-hour measurement after a 50 g load or a fasting serum glucose measurement do not specify the particular condition diagnosed as impaired glucose tolerance. Instead, they relate to different metabolic states such as a possible glucose challenge test result or fasting hyperglycemia, which are separate criteria for diabetes diagnostics. This highlights the importance of the 2-hour measurement after the glucose load as the key parameter for assessing impaired glucose tolerance.