Rethinking A1c goals for type 2 diabetes

“Treat the patient, not the number.” This is a very old and sound medical school teaching. However, when it comes to blood sugar control in diabetes, we have tended to treat the number, thinking that a lower number would equal better health.

Uncontrolled type 2 diabetes (also known as adult-onset diabetes) is associated with all sorts of very bad things: infections, angry nerve endings causing chronic pain, damaged kidneys, vision loss and blindness, blocked arteries causing heart attacks, strokes, and amputations… So of course, it made good sense that the lower the blood sugar, the lower the chances of bad things happening to our patients.

Tracking blood sugar control over time

One easy, accurate way for us to measure a person’s blood sugar over time is the hemoglobin A1c (HbA1c) level, which is basically the amount of sugar stuck to the hemoglobin molecules inside of our blood cells. These cells last for about three months, so, the A1c is thought of as a measure of blood sugars over the prior three months.

Generally, clinical guidelines have recommended an A1c goal of less than 7% for most people (not necessarily including the elderly or very ill), with a lower goal — closer to normal, or under 6.5% — for younger people.

We as doctors were supposed to first encourage diet and exercise, all that good lifestyle change stuff, which is very well studied and shown to decrease blood sugars significantly. But if patients didn’t meet those target A1c levels with diet and exercise alone, then per standard guidelines, the next step was to add medications, starting with pills. If the levels still weren’t at goal, then it was time to start insulin injections.

While all this sounds very orderly and clinically rational, in practice it hasn’t worked very well. I have seen firsthand how enthusiastic attention to the A1c can be helpful as well as harmful for patients.

And so have experts from the Clinical Guidelines Committee of the American College of Physicians, a well-established academic medical organization. They examined findings from four large diabetes studies that included almost 30,000 people, and made four very important (and welcome!) new guidelines around blood sugar control. Here’s the big picture.

Doctors and patients should discuss goals of treatment together and come up with an individual plan

Blood sugar goals should take into account a patient’s life expectancy and general health, as well as personal preferences, and include a frank discussion of the risks, benefits, and costs of medications. This is a big deal because it reflects a change in how we think about blood sugar control. It’s not a simply number to aim for; it’s a discussion. Diabetes medications have many potential side effects, including dangerously low blood sugar (hypoglycemia) and weight gain (insulin can cause substantial weight gain). Yes, uncontrolled blood sugars can lead to very bad things, but patients should get all the information they need to balance the risks and benefits of any blood sugar control plan.

An A1c goal of between 7% and 8% is reasonable and beneficial for most patients with type 2 diabetes…

…though if lifestyle changes can get that number lower, then go for it. For patients who want to live a long and healthy life and try to avoid the complications of diabetes, they will need to keep their blood sugars as normal as possible — that means an A1c under 6.5%. However, studies show that using medications to achieve that goal significantly increases the risk of harmful side effects like hypoglycemia and weight gain. To live longer and healthier and avoid both the complications of diabetes as well as the risks of medications, there’s this amazing thing called lifestyle change. This involves exercise, healthy diet, weight loss, and not smoking. It is very effective. Lifestyle change also can help achieve healthy blood pressure and cholesterol levels, which in turn reduce the risk for heart disease. And heart disease is a serious and common complication of diabetes.

Lifestyle change should be the cornerstone of treatment for type 2 diabetes. The recommendations go on to say that for patients who achieve an A1c below 6.5% with medications, we should decrease or even discontinue those drugs. Doing so requires careful monitoring to ensure that the person stays at the goal set with his or her doctor, which should be no lower than 7%, for the reasons stated above.

We don’t even need to follow the A1c for some patients

Elderly patients, and those with serious medical conditions, will benefit from simply controlling the symptoms they have from high blood sugars, like frequent urination and incontinence, rather than aiming for any particular A1c level. Who would be included in this group? People with a life expectancy of less than 10 years, or those who have advanced forms of dementia, emphysema, or cancer; or end-stage kidney, liver, or heart failure. There is little to no evidence for any meaningful benefit of intervening to achieve a target A1c in these populations; there is plenty of evidence for harm. In particular, diabetes medications can cause low blood sugars, leading to weakness, dizziness, and falls. There is the added consideration that elderly and sick patients often end up on a long list of medications that can (and do) interact, causing even more side effects.

The bottom line

There is no question that type 2 diabetes needs to be taken seriously and treated. But common sense should rule the day. Lifestyle changes are very effective, and the side effects of eating more healthfully and staying more active are positive ones. Every person with type 2 diabetes is an individual. No single goal is right for everyone, and each patient should have a say in how to manage their blood sugars and manage risk. That means an informed discussion, and thoughtful consideration to the number.


Hemoglobin A1c targets for glycemic control with pharmacologic therapy for nonpregnant adults with type 2 diabetes mellitus: A guidance statement update from the American College of Physicians. Annals of Internal Medicine, March 2018.

An overview of the management of diabetes in non-pregnant adults. MGH Primary Care Office Insite, updated June 2016.

Management of persistent hyperglycemia in type 2 diabetes mellitus. UpToDate, updated April 2017.


  1. David Vetter

    Is there research looking at differences in individual susceptibility to end-organ damage from high serum glucose levels in Diabetes? (in other words, there seems to be a subset of patients who have A1c’s well above target for decades, and yet show no signs at all of microalbuminuria, diabetic retinopathy, or diabetic neuropathy. )

    Perhaps part of the individualized approach to intensity of diabetes management (until the genetics of susceptibility to damage are better-defined perhaps) could be based on early signs (or lack of late signs) of end-organ damage independent of A1c levels.

  2. Mohammed Abdulaziz

    Thanks for these valuable information you’d just mentioned about diabetic and A1C test.

    I’ve two questions to ask..

    the first question, there are discrepancies between the guidelines on what is the cut off limit of A1c, for example, World Health Organization (WHO) (2011) considered 6.5% as the limit for this test, whereas The National Institute of Diabetes and Digestive and Kidney Diseases considered 5.7% as the limit for the same test. does these variations of the limits has any difference in term of the risk on diabetic patients.

    it is widely known that the reasons behind this disease are not clear even thought there are known contributing risk factors like obesity and genetics. my second question is about the possible causes, do you think that “hygiene hypotheses” might be considered as one of the causes of diabetics. as this conditions according to some studies might negatively trigger the autoimmunity.


  3. Ch. R.

    To rethink A1C Goals and to fight the Epidemic by improved
    Awareness, Pre-Diabetes should be from A1C 5.3% or higher
    and Diabetes should been defined as from 6% or higher.
    Many Doctors complain that by today’s 20 years old definition
    of A1C 6.5% until reached already too many damages occur.
    This under the view that A1C of 5.5-6% has already the double
    heart failure risks compare to the normal healthy A1C of 5% as
    proven here in the NIH.Gov Link of 2010:

    • Ch. R.

      The only reliable numbers we presently have from ADA is for
      the Pre-Diabetic Fasting Glucose of 100 – 125 mg/dl, where
      the Average Glucose of 125 mg/dl represents A1C of 6% !

      • Ch. R.

        The Health Insurances would not like to see Diabetes defined as
        from A1C 6% and the under political pressure Epidemiologists
        also would not like to see this, because it would increase the
        numbers of Diabetics where they try to keep the numbers
        down and the ADA remains in its conflicts of interests.

  4. Edwin

    The ACP guideline are the most unscientific and irresponsible publication. The studies they used did not used the newer agents we have now. Glp1ra, SGLT2i and DPP4i. Not all medication in diabetes management are created equal when taking in consideration CV data. A person who is 65< can easily surpass 10yrs with good medical care. Ignoring the abundant amount of evidence that demonstrates higher glucose levels causes damage to the patient. Hypoglycemia is a risk when using hypoglycemic agents. With other agents, they can achieve a better glucose control with no hypoglycemia risk.
    Cost most of the expenses in DM is not on medications but on complication from the disease.

    • Ch. R.

      Edwin – That’s exactly what you mentioned. Just not using any
      medications with Hypo risks and that’s why I proposed the very
      simple but very effective therapy by Metformin Glucophage SR
      and 24 hours Basal-Insulin as Toujeo which so fine can been
      dosed to set at lowest Fasting Glucose of 80 – 90 mg/dl where
      resulting Hypos impossible and the injection by the right technique
      can been made pain free as I do it every day. With that therapy
      I know many Hypo free with A1C of less 5.6% like normal healthy
      people without any problems.

  5. Ch. R.

    Any good and responsible Prof. Dr. in Endocrinology for in favor
    of the T2D patients, is shaking the heads about A1C of 7 – 8%.

    It is really disturbing how the matters related to Type 2 Diabetes
    just get complicated and confused and that principally where any
    Type 2 by the right therapy could easy and without any Hypos
    have the A1C of any normal healthy peoples, not like at Type 1.
    For example the well experienced Metformin does not create any
    Hypos and is still the best to control the Liver-Glucose production.
    Daily 2x every 12 hours Glucophage SR 850mg or 1000mg ( SR =
    Slow Release over 14 hours ) is not creating any digestion problems.
    This combined with a 24 hours Basal-Insulin as Toujeo to set the
    lowest Fasting Glucose at 80 – 90 mg/dl for best preconditions.
    This offers a 4x daily action, first in the morning measuring the
    Fasting Glucose, take one Glucophage SR Tablet and inject the
    Basal-Insulin dose and after 12 hours take one more Glucophage
    that’s all for the day and provides an A1C of less 6% as more in
    direction of normal healthy peoples and this can be made at any
    ages or dementia. Why not applying the commonsense therapy.

    Further there is not enough considerations taken for the Potassium
    Level which for Diabetics should been in the upper halve of the
    normal. Remember no Potassium no heartbeats and this where it
    also for the Glucose Metabolism plays a key role and this where
    by the scientists is confirmed that today worldwide there is a
    Potassium deficiency in the populations.
    Potassium should been supplemented also at normal healthy people.

    Additionally Type 2 Diabetics which by any diets or exercise cannot
    reach the normal bodyweight, should receive bariatric surgery as a
    normal standard.
    There is enough proof worldwide that if the normal bodyweight is
    reached, that often the Type 2 disappears and the need for any
    medications also or at least much reduced and this also proves
    that Type 2 is not just a progressive disease as the medical
    industries like to interpreting it.

    I’m myself Diabetic with a normal bodyweight and if I go to any
    normal doctor he would not find out about if I don’t tell or only
    if would do a Peptide-C test then would see about 30% not enough.
    My A1C is at about 5% without any Hypos and my Heart function
    is SIS 110-120 DIA 65-70 by Pulse 60-70 as it always was and this
    with 67 years old and smoking for 30 years, I like to stop now.
    I have to admit, that I learned a lot at Google “Twitter WDHCO”.
    Diabetes is not that complicate if we just apply commonsense.

  6. Neil Farbstein

    The American College of Physicians wants to change standards for A1C levels for no reason other than economics.
    They are lying its safe for diabetics to take cheaper medicine that doesnt lower their blood sugar and total hemoglobin gesticulation levels.
    People’s health should come before insurance company profits. THEY ARE BUNCH OF GREEDY LIARS. Diabetic should have class action lawsuit against those doctors.

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