Caring Currents

Diabetes A1c Test: Out With the Old and In With the New

Last updated:

August 21, 2008

Flummoxed by those pesky percentages measuring glycated hemoglobin (whatever that is)? Unsure what that frequently flaunted 7 percent actually means and how it relates to home blood sugar monitoring? You're not alone.

But help may be around the corner for people with diabetes and their caregivers. Changes to the traditional, gold standard blood test (known as the A1c test ), which provides a guide to glucose control over the past 90 days or so, may be coming soon to doctor's offices.

The switch is supposed to make life easier for everyone -- there are skeptics -- juggling the multiple health statistics that provide a snapshot of how well a person with diabetes is managing the disease. The new numbers, known as estimated average glucose or eAG, are measured in units that should look familiar to anyone who does finger-stick testing: milligrams/per deciliter of blood, or mg/dl.

Why the change? The party line from the American Diabetes Association is that the A1c test is considered a terrific tool for estimating the risk of long-term diabetes complications, by showing how much sugar attaches to the hemoglobin molecules in red blood cells over two to three months. This information can help someone with diabetes tailor treatments to try to keep bad stuff -- like eye disease, kidney failure, heart disease, and stroke -- from surfacing.

But the percentage figure apparently causes confusion in the doctor's office. A large international study recently devised a mathematical equation that can translate A1c levels in a way that correlates closely with the numbers that pop up on the screen after finger-prick monitoring. The conventional thinking is that expressing an A1c as an eAG could, in theory, improve physican-patient communication around diabetes management.

You following all this? To keep track of both numbers easily, go to the ADA's website to access an online calculator so that you can convert from A1c to eAG at the click of a mouse. In addition to the new eAG, labs will likely continue to measure A1c as well. For the insider scoop on the ol' number switcheroo, check out the post on this subject by the ever-insightful Amy Tenderich at Diabetes Mine.

What does all this number mumbo jumbo mean for someone with diabetes?

Just two things really:

1. Educate yourself and the person you're caring for about what those A1c numbers mean. (In a nutshell: aim for under 7 percent. An A1c for a person without diabetes is typically between 4 and 6 percent.)

2. Make sure the person you're caring for has a glucose meter to monitor blood sugar levels at home and talk with a physician, nurse practitioner, or diabetes educator to check that it's being used correctly, often enough -- and that everyone understands what the figures on the screen mean.

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