Insulin levels above 10 show insulin resistance. Because following a low-carbohydrate diet may lower fasting insulin test results, it is usually recommended that one adhere to a diet that is not carbohydrate restricted for two to three days prior to testing in order to ensure accuracy. Some doctors and labs have specific diet requirements, so patients should request specific instructions if none are given. This test is done to monitor a person's average blood glucose level over the past 3 months or so. It is not usually used to diagnose impaired glucose tolerance or diabetes, but rather to assess glucose control.
Glucose attaches itself to hemoglobin, the protein in red blood cells that carries oxygen.
Since blood cells remain in circulation for 2-3 months, the HbA1c level is a good measure of average glucose level during this time period. A healthy level is less than 6 percent. When a level gets above 6 percent, it indicates some high blood sugar levels. Higher levels may indicate risk for organ and nerve damage. In someone who is trying to get pregnant, it is important to have blood sugar under control as elevated levels increase the risk of serious birth defects.