Your fasting insulin level reflects how healthy your blood glucose levels are over time. Insulin helps sugar move from your blood into your cells, where it can be used or stored. Chronically elevated blood glucose leads to insulin resistance and numerous chronic diseases, including diabetes and heart disease. Elevated blood glucose and insulin resistance are epidemic today. An estimated one in four Americans are either insulin resistant or diabetic.
I work with an endocrinologist and not once has he did an insulin level test..Have you had it done before?
Source – http://fitness.mercola.com/sites/fitness/archive/2012/04/27/vitamin-d-and-blood-test-health-factors.aspx