--with glucose tolerance testing, one does need a longer test (at least three hours after the initial baseline "stick", although I generally do five) to really see the patterns of how the bodily process of digesting/releasing the glucose to one's body causes one's individual glucose regulaiton patterns.

I always have them done not only with a fasting insulin level, but with insulin levels drawn concurrently all the way through. That way, when the results come in, one can trace the insulin reaction to the glucose challenge, see if it is measured or exaggerated (the latter is a sign of insulin resistance) and just how exaggerated (which may result in reactive hypoglycemia, as Mrs. D mentions).

The reason for the longer testing is to cover everybody's varied alimentary speed--by 4-5 hours most people's systems have gone through a complete cycle and are heading bck to baseline readings, and all the insulin/glucose patterns have been cycled through.

Also--while this may make you feel like a pincushion--I have readings taken every half-hour, not every hour. For people with faster systems, taking a reading only every hour may miss some of the rise/fall patterns in glucose and/or insulin that may provide diagnostic clues. (In other words, you want enough "snapshots" taken to see the pattern.)