Which specimen type is NOT typically used for a glucose tolerance test?

The glucose tolerance test is primarily designed to assess how well the body processes glucose and is most commonly conducted using blood samples. In a typical glucose tolerance test, blood is drawn before the patient consumes a specific amount of glucose, followed by additional blood samples taken at intervals to measure how quickly the glucose is cleared from the bloodstream.

While urine can provide some information about glucose levels and may be involved in certain evaluations, it is not the primary specimen used for the glucose tolerance test itself. Saliva, on the other hand, is not utilized in traditional glucose testing protocols. High-profile studies have not established adequate protocols or reliability surrounding the use of saliva for glucose measurement in this context, making it the least relevant specimen type among the options provided.

Thus, the correct answer is that saliva is not typically used for a glucose tolerance test.