Study results continue to confirm target A1C of 6.5 may be ideal for long term management of diabetes.
Few things I’ve ever written about get the impassioned response of discussing A1C targets. (I should probably be putting a fire suit on right now) Both as people with diabetes and clinicians we tend to fall on one side or the other when it comes to A1C targets. Either we are focusing just to stay below a goal that will likely lead to complications and shortened life span, or we are driving toward lower and lower A1Cs to get as far from those complication risks as we can get. A1C levels start to feel very imposed, or very personal. Suggesting that they need to be higher or lower can become a place of shame, judgement, defensiveness and pride. Sometimes it even feels like we can not trust the recommendations that we receive from our healthcare providers. The American Diabetes Association recommends an A1C under 7, but the American Association of Clinical Endocrinologists recommends under a 6.5, then the American College of Physicians raised their recommended A1C to below 8 for people with Type 2 diabetes! Trying to find a healthy and reasonable goal in a sea of debate can be very frustrating.
Hemoglobin A1C, (HbA1C), better known as A1C is a measurement that represents the average blood glucose levels over the past 2-3 month period for most individuals. An A1C greater than 6.5 is diagnostic of diabetes.
In the 2008 ACCORD trial it was found that patients in intensive diabetes management programs who had an A1C below 6 had an increased risk of cardiovascular complications to those with an A1C of 6-6.5 Likewise, those with an A1C greater than 7 had similar increased risks. This has lead to more recommendation of an A1C of 6.5 as well as increased research and study into the cause of reduced risks at an A1C of 6.5.
A study recently published in the Journal of Clinical Endocrinology and Metabolism also points to 6.5 as a target A1C due to its association with a reduced risk of all cause mortality. This study found that for people with diabetes an A1C less than 5.6 or higher than 7.4 there was a marked increase in all cause mortality than for those patients with an A1C of 6.5.
This study followed participants with and without diabetes, a median age of 64 and no history of cancer, for 5.8 years and studied correlative factors of causes of death in that period(2133 cases). It also showed that for patients who did not have diabetes an A1C of 5.4 to be ideal. For these patients an A1C below 5 correlated to a significant increase in all cause mortality, but A1C greater than 5.4 did not show an increase in mortality. This is particularly interesting as the indication is that for people with or without diabetes there is no increased risk of mortality with an A1C between 6 and 6.5.
We still have no idea why a lower A1C correlated to increased risks and deaths. It has been hypothesized that the inflammatory impact of repeated or chronic hypoglycemic episodes may have a similar impact on the micro and macro vasculature to chronic hyperglycemia. Whether increased stress hormones related to hypoglycemic episodes increase all cause mortality risk, or increased insulin or medication use to drive blood sugars farther down play a roll is unknown.
More goes into A1C targets and risk factors than just an ideal number. Age, comorbidities, hypoglycemia risk, cardiovascular disease, age at diabetes onset and duration of diagnosis all play a roll in the right A1C for each individual. However with more evidence pointing to the benefits of an A1C of 6.5 perhaps more of us should take this goal into account.
Are we pushing too hard to get our A1C lower and lower for fear of complication risks when we may, in fact, be driving ourselves to a higher risk profile? Could we manage our diabetes better, longer with an A1C of 6.5 than 6? Are we happy coming under our doctor’s goal of a 7.5 when, with a little more intensity, change in medication, or the addition of technology, we would get closer to an A1C of 6.5 that would reduce our long term risk factors and help us live longer, better?
Here at Integrated Diabetes we don’t focus on A1C so much as time in range for diabetes management, but A1C is still the gold standard of measurement used for clinical studies. We work with our clients to pursue healthy blood sugar targets and to also help them find a level of diabetes management that improves their quality of life today and maintains that quality for the long term.
So I’m sitting at an A1c of 4.9% currently, averaging 93% TIR with a usual standard deviation of 20 or less. And this is outing me at risk for cardiovascular disease???
Hi Susan,
Yes Studies have shown that long term complication risk begins to increase below an A1C of 6.
Your individual risks will, of course vary, but yes a lower A1C may, in fact, raise risk factors. The causative factors are still unknown. Even in diabetes management the law of diminishing returns seems to hold true.
So did you say suggested time in range for type 2? Type 1? Too many people want to say it depends, perhaps a given reply is good for 80%. Good info this issue, Gary. I like to see suggestions in article trying to remain positive. Why? I am T 2 40 years at age 75I
I have read in range 70%+ on T1 and perhaps 85%+ for T2. .
Hi Jim, thanks for the feedback!
Recent recommendations are 70% with people with Type 1 and 85% for people with Type 2, but it is, as you said, highly individualized dependent on other risk factors, comorbidities etc. And what determines and individual’s target range can also vary.
Way to go, 40 years in and still striving for excellence and education!! Inspirational!