Study: Diabetes Blood Sugar Control for U.S. Adults Is Getting Worse

A woman testing her blood sugar.

Oscar Wong / Getty Images

Key Takeaways

  • A new study finds that over the past decade, people with diabetes in the U.S. have been less successful in controlling their blood sugar levels.
  • This sudden drop arrives after many years of progress.
  • Experts are concerned about the potential health complications these uncontrolled levels can bring.

An estimated 34.2 million people of all ages—10.5% of the U.S. population—have diabetes. But a new study finds that over the past decade, people with diabetes in the U.S. have been less successful in controlling their blood sugar levels.

The June study, which was published in the New England Journal of Medicine, analyzed data from 1999 through 2018 in adults with diabetes—a condition that occurs when your blood sugar levels are too high.

Researchers analyzed data from 6,653 participants who were at least 20 years old, not pregnant, and were diagnosed with the condition.

They found that the percentage of people who were able to control their blood sugar—or glycemic control—increased from 44% between 1999 and 2002 to 57.4% between 2007 and 2010. But the numbers fell to 50.5% from 2015 to 2018.

Patients who were able to control their blood pressure rose from 64% in 1999 to 2002 to 74.2% in 2011 to 2014. Those numbers also dropped, hitting 70.4% from 2015 to 2018.

The researchers noted in the study’s conclusion that these negative changes happened “after more than a decade of progress.”

“These are concerning findings,” study co-author Elizabeth Selvin, PhD, MPH, a professor in the Johns Hopkins Bloomberg School of Public Health, said in a press release. “There has been a real decline in glycemic control from a decade ago, and overall, only a small proportion of people with diabetes are simultaneously meeting the key goals of glycemic control, blood pressure control, and control of high cholesterol.”

Why Are Blood Sugar Levels Getting Worse?

Doctors say they’re witnessing these results in the field.

“These findings are consistent with what I see in daily diabetes management and what I hear from colleagues around the country,” Kathleen Wyne, MD, PhD, director of the Adult Type 1 Diabetes Program at The Ohio State University Wexner Medical Center, tells Verywell.

The study’s researchers note that two large clinical trials that were published in 2008 may have influenced this decline.

The trials—called the ACCORD and ADVANCE trials—found that reducing blood sugar to very low levels (measured by a test called an A1c) didn’t produce the heart benefits that doctors hoped for. Some trial participants who managed to control their blood sugar to very low levels also experienced increased risks of low blood sugar or hypoglycemia.

Doctors started “accepting higher sugars as normal” and no longer pushed patients to get their A1c levels to a specific low target, Wyne says.

Around the same time, “we realized that some of the older generations of medications to treat diabetes were unsafe, and we cut down on the use of them,” Elena Ghiaur, MD, an internist at Baltimore’s Mercy Medical Center, tells Verywell.

There has also been “a lag” in adopting some new medication, she says, which could cause some patients to develop higher blood glucose levels. “We loosened the grip on diabetes control,” she says. “We may have overdone it.”

But David Cutler, MD, family medicine physician at Providence Saint John’s Health Center in California, tells Verywell that it’s difficult to say that the data applies to all Americans with diabetes, given that only about 1,000 to 1,700 people were in each of the five study periods.

The study also had participants recall information, like what kind of medication they used, which can be unreliable, he says. 

“If, in fact, these results reflect real decline in diabetes control, the long-term results could be devastating,” Cutler says. “Diabetes takes years to produce its destructive effects on vision, kidney function and circulation leading to blindness, renal dialysis and amputations, not to mention deaths from heart attacks and strokes. As our population ages, we may face a far greater health care burden in managing these problems. The individuals and families suffering these diseases will suffer the greatest consequences.” 

What This Means For You

If you have diabetes, it's crucial that you carefully monitor your blood glucose levels. If they're high, talk to your doctor about your next steps and a treatment plan that can help you.

How You Can Manage Your Blood Sugar

If you have diabetes, doctors recommend staying top of your blood glucose levels and actively working to lower them if they’re high.

Working on your blood glucose levels can help you have more control over your life, Wyne says. People who aren’t able to manage their blood glucose can “lose self-esteem, lose the ability to believe that they can succeed in other goals, and may develop depression,” Wyne says.

You also may feel physically ill, which can lead to more sick days, she says.

If you’re struggling to control your blood glucose levels, talk to your doctor. “Ask your doctor why you’re not doing better and what you can do to improve control to prevent complications,” Wyne adds.

To help manage your blood sugar levels, the Centers for Disease Control and Prevention (CDC) recommends you:

  • Keep track of your blood sugar levels to see what makes them go up or down.
  • Eat at regular times, and don’t skip meals.
  • Choose foods lower in calories, saturated fat, trans fat, sugar, and salt.
  • Track your food, drink, and physical activity.
  • Drink water instead of juice or soda.
  • Limit alcoholic drinks.
  • For a sweet treat, choose fruit.
  • Control your food portions.
4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. National diabetes statistics report 2020.

  2. Fang M, Wang D, Coresh J, Selvin E. Trends in diabetes treatment and control in U.S. adults, 1999–2018N Engl J Med. 384(23):2219-2228. doi:10.1056/NEJMsa2032271

  3. Action to Control Cardiovascular Risk in Diabetes Study Group. Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med. 358(24):2545-2559. doi:10.1056/NEJMoa0802743

  4. Centers for Disease Control and Prevention. Manage blood sugar.