Diabetes mellitus happens when the body can’t respond to or make insulin.

This allows glucose to build up in the bloodstream. The pancreas produces insulin, helping your cells take up glucose and convert it to energy. When the pancreas doesn’t make enough insulin, or your body is resistant to the present insulin, excess glucose in the bloodstream sets the stage for diabetes.

Diabetes affects nearly eight million people in the U.S. It plays a large role in cardiac and vascular disease, and strokes. It can also cause injury to the eyes, kidneys and other parts of the body.

There are two types of diabetes. Type 1 diabetes is generally diagnosed in children who are then insulin-dependent. Type 2 diabetes is usually adult-onset and non-insulin-dependent.

Additionally, there’s a form of pre-diabetes called impaired glucose metabolism (IGM). IGM is found in people with increased waist size, upping the risk for developing heart disease and type 2 diabetes.

If you suspect you have diabetes, ask your doctor about these tests:

Fasting Blood Glucose Level: A level from 79 to 99 mg/dL shows normal glucose metabolism. A level from 100 to 125 mg/dL represents impaired glucose metabolism. A level above 125 mg/dL on two different occasions shows the presence of diabetes.

Hemoglobin A1C (HbA1c): This biomarker level indicates the average amount of blood glucose over time. HbA1c levels aren’t influenced by daily fluctuations in the blood glucose concentration. An insulin measure helps determine whether the high glucose reading is the result of poor use of insulin or insufficient insulin. People with type 2 diabetes mellitus may have elevated insulin levels.

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