Diabetes Mellitus

There are three test methods used to diagnose diabetes and each must be confirmed, on a subsequent day, by any one of the three methods. The first method includes symptoms of diabetes (increased urination, increased thirst, unexplained weight loss) plus a casual plasma glucose concentration (blood test taken any time of day without regard to time since last meal) of equal to or greater than 200 mg. The second test method is a fasting plasma glucose (no caloric intake for at least eight hours) of equal to or greater than 126 mg. The third method is a two-hour after meal blood sugar of equal to or greater than 200 mg during an oral glucose tolerance test. Testing for diabetes should be considered in all individuals at age 45 years and above (particularly if overweight), and if normal, should be repeated every three years. Testing should be considered at a younger age or carried out more frequently in individuals who are overweight and who have additional risk factors among the following:

• first-degree relative with diabetes
• habitually physically inactive lifestyle
• member of high-risk ethnic population (African-American, Hispanic-American, Native American, Asian American, Pacific Islander)
• previous delivery of baby weighing greater than 9 lb (4.1 kg) or history of gestational diabetes
• high blood pressure
• HDL cholesterol less than 35 mg or a triglyceride level greater than 250 mg.
• PCOS (polycystic ovarian syndrome)
• impaired glucose tolerance or impaired fasting glucose
• history of vascular disease.

Other tests used in the management of diabetes include c-peptide levels and hemoglobin A1c levels. C-Peptide levels determine if the body is still producing insulin. C-Peptide is the connecting peptide portion of the insulin molecule that is produced in the pancreas. C-Peptide and insulin are secreted into the bloodstream in equal amounts by the pancreas. Measurement of C-Peptide is a reliable indicator of the amount of insulin produced by the person's pancreas. HbA1c (hemoglobin A1c) measures the average blood sugar control over a 2–3 month period. The A1c goal recommended by the American Diabetes Association is <7%, which correlates with average blood sugars of less than 150 mg.