I posted this in your other thread too. I actually asked my doctor why not and this was essentially what he said, same as this link:

http://www.diabetes.niddk.nih.gov/d...ance/#diagnosis

"However, the test that most accurately measures insulin resistance, called the euglycemic clamp, is too costly and complicated to be used in most doctors’ offices. The clamp is a research tool used by scientists to learn more about glucose metabolism. If tests indicate pre-diabetes or metabolic syndrome, insulin resistance most likely is present."

Syrah, I can almost certainly echo your above post too, it applies to me the same. I wish I'd known sooner what was going on and essentially I had to figure it out myself.