Most people with A1C of 7 do have diabetes

DEAR DR. ROACH »

My recent fasting blood test showed my glucose number as 99, but the

A1C said 7%. My doctor immediately wanted to put me on metformin, but I refused for two reasons:

1. I am a senior, 69 years old, and I heard this medicine’s side effects could be dangerous;

2. I am not convinced I have Type 2 diabetes, because I don’t exhibit any of the symptoms. I am 5 feet, 2 inches tall and weigh 130 pounds, and I am full of energy. I eat healthy and get adequate exercise. However, I am under a lot of stress because I take care of my mom, who has dementia. It’s been nine years. Can stress cause a rise in blood sugar? I have taken Lipitor since 2008, and that’s when the trouble started. Do I really need treatment?

— M.B.

ANSWER » The A1C level measures the amount of sugar molecules attached to hemoglobin, the protein in red blood cells that carries oxygen. In people with normal hemoglobin, the A1C is an accurate representation of the person’s average blood sugar over the past couple of months. A repeated A1C of over 6.5% makes the diagnosis of diabetes.

There are two caveats.

The first is that the A1C is unreliable for people with abnormal hemoglobin or those who have medical conditions causing red blood cells to be broken up too quickly (especially hemolytic anemias) or broken up too slowly (such as iron, B12 or folic acid deficiency). The second is that the level should be confirmed on a different day. Since you don’t have symptoms, confirming the result is particularly important. A glucose tolerance test remains the most accurate way of confirming the diagnosis of Type 2 diabetes.

Most people with an A1C of 7% do have diabetes. You have at least one risk factor for diabetes, and that is the atorvastatin (Lipitor) you are taking. Statins can precipitate diabetes in those predisposed to getting it. It is worth discussing with your doctor your risk for heart disease and reconsidering the need for continued statin use. Chronic stress, which can cause elevated levels of cortisone, does have a small effect on blood sugar, but seldom enough to cause overt diabetes.

Your BMI is 24, which is normal, but individual body composition has an impact on diabetes as well. People with large waist circumference for their height are more predisposed.

Contact Dr. Roach at ToYourGoodHealth@med. cornell.edu.