Sugar Matters
July 11, 2008

Testing, testing

A great big thank you to those of you who have written in with questions. I have received some by e-mail and others through the Searchlight office, so keep them coming Vincies!

One question from a devoted reader was in regard to a common test called the Hemoglobin A1C. We spoke via e-mail, but I thought many of you might have the same question, so this week we tackle:{{more}}

The Hemoglobin A1C/HbA1C-this test has changed the way diabetes is managed entirely, and appropriately the folks that developed it won some awards for their research. This blood test is one of the ways we can track how high your blood sugar is over a longer period of time. Unlike the glucose that you measure on your glucometer or finger stick that is a one-time value, the Hemoglobin A1C gives an average of your blood sugars over about 3 months. I call it “the lie detector test” because I have had many patients tell me their blood sugars are great but then their hemoglobin A1C is terrible-caught!!!

The current recommendations are for the hemoglobin A1C to be measured about every 3 months as part of regular diabetes management, and the goal is to have a value at or less than 7%. The higher your HbA1C, the higher your average sugar numbers, and the more likely you are to develop problems from diabetes like heart, nerve and kidney disease. We know that at a value of 7% your chances of developing any of those problems are much lower, even if you continue having diabetes. For some people, including the elderly and very young children, the HbA1C goal can be loosened up to avoid possible low blood sugars which can be very serious for these two groups.

A common scenario arises when a patient brings in a log of their measured glucose numbers that look okay but their Hemoglobin A1C does not match. If the A1C is higher than you expect, the most likely reason is that your glucoses are high during periods that you did not measure, for example after eating. Remember, the HbA1C is an average of ALL glucoses, those you measure and those you don’t. So often an unexpectedly high HgBA1C is a trigger investigate your sugars a bit more.

Can the HbA1C be wrong? Of course, it can. There are no perfect blood tests, and while this one is great it does have some limitations. Also, there are certain medications and conditions that can make it falsely low or high. Your blood sugars, measured by finger stick and the HbA1c, do have a relationship that corresponds over various levels. So, if something doesn’t quite stack up when your doctor looks at both, then some investigation should be done to see what is amiss. For example, people with low blood counts can have a falsely low HbA1C-the measured number may look great, but in reality your sugars may be much higher. But overall it is a great test and very useful for your care.

Thanks for the question! Until next week, stay well and healthy Vincies.

Anita Ramsetty, MD endodocs@endocrinehelp.com
Medical Director Endocrine Care Group
www.endocrinehelp.com
Tel: 843-798-4227