When it comes to treating diabetes, many doctors still don’t get it: Trying too hard to lower blood sugar levels through drugs can be harmful.

That’s especially true if you have to take multiple medications to get your blood sugar really low. As you get older, the dangers of overtreatment only get worse, diabetes experts warn.

Yet when nearly 600 primary care providers were asked to evaluate a hypothetical case of a man whose medication regimen was bringing his blood sugar dangerously low, many missed the risks.

Here’s how to protect yourself from an overzealous doctor and too much diabetes treatment.


Make no mistake. Keeping your blood sugar level well-regulated is important—for everyone. If you have diabetes, a chronically elevated blood sugar level can lead, over time, to a host of complications including heart disease, vision problems and nerve pain. Reducing blood sugar reduces the risk–or at least slows the progression–of these related ills.

The question is, how low should your goal be? To measure blood sugar over weeks or months, doctors use a test called A1c. A healthy person without diabetes generally has an A1c of 4.5% to 6%. Someone with diabetes may have an A1c of 7% or 8% or 9% or even higher. It’s important to bring high A1c levels down—first through lifestyle changes, and, if needed, with medications.

But taking lots of drugs to bring A1c down really low can backfire badly. In a now-classic study of more than 10,000 men and women with diabetes (average age 62), published in The New England Journal of Medicine in 2008, those who underwent “intensive” drug therapy to bring their A1c levels down toward a goal of below 6% were compared to others given standard drug therapy with a goal of 7% to 8%.

Result: Those trying to reach the target goal were more likely to gain weight, have low blood sugar episodes—and to die from cardiovascular disease and other causes. As a result, guidelines for doctors now warn against trying to bring blood sugar levels as measured by A1c too low (see below for specifics).

But the latest research shows that the message hasn’t gotten through to primary care providers.


In the new study, conducted by researchers at the University of Michigan and the Veterans Administration, 594 primary care providers (PCPs)—physicians, nurse practitioners and physician assistants—were given this case history a 77-year-old man with diabetes that’s controlled by drugs. This hypothetical patient also has high blood pressure and kidney disease, and he takes four prescription drugs, plus Tylenol for lower back pain.

His A1c is 6.5%.

The PCPs were asked if they thought that keeping his blood sugar at this level was a good goal for this patient, and 252 of them—45% of the total—thought the goal was just fine.

But it’s not.

“Tight control,” as this medical approach is called, not only leads to worse health outcomes but it also makes patients feel terrible. A double whammy! As lead study author Tanner Caverly, MD, MPh, general internist at Ann Arbor Veterans Affairs Center for Clinical Management told The New York Times, “People can feel fatigued and weak, get cold sweats, feel like they’re going to pass out.”


“Tight control” isn’t always the wrong approach. If you’re relatively young—in your 50s, for example—you’ll have a long time to get the benefits of low blood sugar, which include preventing, or at least slowing down, complications such as heart disease. So it may make sense to try an aggressive lifestyle program, along with medication if necessary, to bring your A1c below 7%. But taking multiple medications for this goal is a bad idea whatever your age. Only one drug, metformin, is safe to use for that purpose—using other drugs to reach this goal actually increases mortality risk, according to the American Geriatrics Society (AGS).

As you get older, the likelihood that keeping your A1c low will protect your health diminishes because it takes decades of really low A1c levels to see benefits, and the risks get riskier—including episodes of too-low blood sugar (hypoglycemia) that can land you in the hospital (and can be fatal) and fainting spells that could mean a debilitating fracture.

For adults 65 and older, the AGS recommends…

• An A1c target of 7% to 7.5% in healthy older adults with a long life expectancy.

• A target of 7.5% to 8% in those with moderate comorbidity (other medical conditions) and a life expectancy of less than 10 years.

• A target of 8% to 9% in those with multiple comorbidities and a shorter life expectancy.

To learn more, see Bottom Line’s Outsmart This Diabetes Treatment Trap, Don’t Be One of the Millions of Americans Overtreated for Diabetes and Bottom Line’s Guide to Natural Ways To Manage Diabetes.