Senior Health

4/5/2022 | By Howard LeWine, M.D.

“What’s a good level for me to avoid low blood sugar?” The Harvard experts look at tight control and loose control of diabetes, especially for older diabetics.


I have had Type 2 diabetes for almost 25 years. I am now 81 years old. I still take both pills and insulin for my diabetes, but I think my doses are too high. What’s a good level for me and other older diabetics to avoid low blood sugar?

Of special importance to older diabetics:

The American Diabetes Association recommends striving for a hemoglobin A1C (HbA1C) blood level of less than 7% in most people with diabetes. But that might not be best for you.

HbA1C reflects a person’s average blood sugar during the last 2 to 3 months. A 7% HbA1C translates to an average blood sugar of 154 milligrams per deciliter. Doctors call achieving the goal of 7% or less “tight control.”

For people with Type 1 diabetes, tight control clearly improves health outcomes. However, for some people with Type 2 diabetes, tight control might cause more harm than benefit. According to a recent report, that’s especially true for many older diabetics.

Tight control greatly increases the risk of low blood sugars (hypoglycemia). Episodes of hypoglycemia can lead to falls, fractures, seizures, head injuries and problems with memory and thinking if hypoglycemia happens often.

Related: A healthy lifestyle for those with Type 2 diabetes

Aiming for tight blood sugar control makes sense for almost everyone when they are first diagnosed with Type 2 diabetes. Early on tight control can often be achieved with diet and exercise and minimal drug treatment.

But tight control for many older people with long-standing diabetes means frequent hypoglycemia. So, your concern is well founded.

Talk with your doctor about the best blood sugar goal for you. For example, he or she may now advise moderate control, keeping an HbA1C level between 7.1% and 8.5%. This translates to average blood sugars that are still less than 200 milligrams per deciliter.

Also ask your doctor what you should do to avoid hypoglycemia if you get sick and cannot eat. You may need to lower or skip doses of your medications. A blood sugar that is a bit high generally is less dangerous than a very low blood sugar, especially in older people with long-standing Type 2 diabetes.

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Howard LeWine, M.D.

Howard LeWine, M.D., is an internist at Brigham and Women’s Hospital in Boston and assistant professor at Harvard Medical School. For additional consumer health information, please visit