The Nation's Health

High HbA1c: You're getting older . . . faster

Over the years, we all accumulate Advanced Glycation End-products, or AGEs.

AGEs are part of aging; they are part of human disease. AGEs are the result of modification of proteins by glucose. AGEs form the basis for many disease conditions.

Accumulated AGEs have been associated with aging, dementia, cataracts, osteoporosis, deafness, cancer, and atherosclerosis. Most of the complications of diabetes have been attributable to AGEs.

There's one readily available method to assess your recent AGE status: HbA1c.

Hemoglobin is the oxygen-carrying protein of red blood cells. Like other proteins, hemoglobin becomes glycated in the presence of glucose. Hemoglobin glycation increases linearly with glucose: The higher the serum or tissue glucose level, the more glycation of hemoglobin develops. Glycated hemoglobin is available as the common test, HbA1c.

Ideal HbA1c is 4.5% or less, i.e., 4.5% of hemoglobin molecules are glycated. Diabetics typically have HbA1c 7.0% or greater, not uncommonly greater than 10%.

In other words, repetitive and sustained high blood glucose leads to greater hemoglobin glycation, higher HbA1c, and indicates greater glycation of proteins in nerve cells, the lens of your eye, proteins lining arteries, and apoprotein B in LDL cholesterol particles.

If AGEs accumulate as a sign of aging, and high blood sugars lead to greater degrees of glycation, it only follows that higher HbA1c marks a tendency for accelerated aging and disease.

Indeed, that is what plays out in real life. People with diabetes, for instance, have kidney failure, heart disease, stroke, cataracts, etc. at a much higher rate than people without diabetes. People with pre-diabetes likewise.

The higher your HbA1c, the greater the degree of glycation of other proteins beyond hemoglobin, the faster you are aging and subject to all the phenomena that accompany aging. So that blood glucose of 175 mg/dl you experience after oatmeal is not a good idea. 

The lesson: Keep HbA1c really low. First, slash carbohydrates, the only foods that substantially increase blood glucose. Second, maintain ideal weight, since normal insulin responsiveness requires normal body weight. Third, stay physically active, since exercise and physical activity exerts a powerful glucose-reducing effect. Fourth, consider use of glucose-reducing supplements, an issue for another day.

While HbA1c cannot indicate cumulative AGE status, it can reflect your recent (preceding 60 to 90 days) exposure to this age-accelerating thing called glucose.

If your doctor refuses to accommodate your request for a HbA1c test, you can perform your own fingerstick test.