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New research suggests that continuous glucose monitors may be able to diagnose prediabetes earlier that blood sugar tests, helping people make healthier lifestyle choices sooner. Anchiy/Getty Images
  • A new study has found that prediabetes can be diagnosed by using continuous glucose monitors (CGMs).
  • This method could potentially identify people with early signs of prediabetes, even before it would have been picked up with a blood sugar test.
  • This might encourage people to make lifestyle changes earlier in the progression of the condition.

Millions of Americans are living with type 2 diabetes, which if left untreated, puts them at greater risk of heart disease, vision loss, kidney disease, and dying early.

Even more people have prediabetes, a condition where blood sugar (glucose) levels are higher than normal, but not high enough for a person to be diagnosed with type 2 diabetes.

However, this doesn’t mean that prediabetes isn’t serious.

“Prediabetes is not pre-problem,” said Jill Weisenberger, a Virginia-based registered dietitian nutritionist and author of Prediabetes: A Complete Guide, Second Edition.

“It’s a sign that a problem has been going on for some time and only now has become measurable in blood sugar levels,” she told Healthline.

While prediabetes can be diagnosed with a blood sugar test — the same tests that are used to diagnose type 2 diabetes — a new study found that it can also be diagnosed using continuous glucose monitors (CGMs).

This method could potentially identify people with early signs of prediabetes, even before it would be picked up with a blood sugar test.

This might encourage people to make lifestyle changes earlier in the progression of their disease.

With prediabetes, “now is the time to take action, because the longer the problem continues, the more difficult it gets to manage and to reverse,” said Weisenberger, who was not involved with the new study.

CGMs are devices that measure blood sugar levels in more or less real time.

The sensors for these devices are stuck to the skin with an adhesive patch and take blood sugar readings without the need for regular fingerstick tests.

These devices measure blood sugar throughout the day and track fluctuations, such as spikes in blood sugar after a meal or when blood sugar dips low.

The readings taken can be viewed on a smartphone or another monitor device.

In the new study, published May 24 in Mayo Clinic Proceedings: Digital Health, scientists from Canadian-based Klick Labs used data from CGMs to identify people with impaired glucose homeostasis, which is a precursor to prediabetes.

They found that one in five participants who were diagnosed as healthy, according to current medical standards, actually had a glucose metabolism that resembled people with prediabetes.

“For people with diabetes, blood glucose levels can rise and fall like a wild roller-coaster ride with steep drops and peaks,” study author Jaycee Kaufman, a research scientist at Klick Labs, said in a news release.

In our study, “we found a similar pattern in patients with [impaired glucose homeostasis], albeit those patterns were more like gentle waves than dramatic peaks,” she said. “But intervention on this population could limit the likelihood of progression to full diabetes.”

For the study, a total of 384 participants were equipped with a CGM over a two-week period. During that time, a physician diagnosed them as diabetic, pre-diabetic, or healthy, according to guidelines outlined by the American Diabetes Association.

Researchers used a mathematical model to compare data from participants to data on populations without diabetes, with prediabetes, and with type 2 diabetes. From this, they classified participants into two groups based on their glucose homeostasis patterns: effective or impaired.

If this work is supported by future clinical trials, it could provide a way to diagnose people earlier with prediabetes, when it is easier to intervene.

Dr. Kathleen Wyne, an endocrinologist at The Ohio State University Wexner Medical Center in Columbus, said by focusing on real-time data, researchers are able to identify people earlier in the disease process.

“In fact they [could potentially] identify people earlier than our current methods,” she told Healthline. “This may be early enough to actually slow the progression of the disease.”

In addition, by using CGMs, researchers were able to analyze spikes in blood sugar that occurred after a meal, said Wyne, who was not involved in the new study.

This could “identify those at highest risk of progressing in their glucose intolerance,” she said, “and even predict when they will progress to type 2 diabetes.”

According to the Centers for Disease Control and Prevention, more than one in three American adults — approximately 96 million people — have prediabetes. Of these, more than 80% don’t know they have this condition.

“That means only a small fraction of the people at high risk for type 2 diabetes — as well as heart disease, stroke, and some types of cancer — know that making changes to their lifestyle now is the best way to protect themselves from future disease and disability,” said Weisenberger.

Prediabetes occurs when the cells in the body don’t respond normally to insulin. This hormone is produced by the pancreas and helps blood sugar enter the cells, where it is used as an energy source.

When the cells become resistant to insulin, the pancreas responds by making more of this hormone. Eventually, the pancreas can’t keep up and the blood sugar rises. This increases the risk of health problems, as well as the development of type 2 diabetes.

Risk factors for prediabetes include:

  • Living with obesity or overweight
  • Being 45 years or older
  • Having a parent or sibling with type 2 diabetes
  • Being physically active less than three times a week
  • Having diabetes during pregnancy (gestational diabetes) or giving birth to a baby who weighed more than 9 pounds
  • Having polycystic ovary syndrome

In addition, Black, Hispanic, American Indian, Pacific Islander, and some Asian American people have a higher risk of prediabetes.

Wyne said CGMs could provide useful information for people about their health. The data could also be collected and shared with their doctor, she said, who could help them decide what steps to take.

“For many people seeing the [information] will make it real,” she said, “and help them to understand that their body can not handle certain foods and/or portion sizes.”

However, “people need to be prepared to use that data to learn how to be more healthy in food choices,” she added.

Some research shows that people with prediabetes who make a few healthy lifestyle changes can reduce their risk of developing diabetes by 40% to 70%.

These changes include losing a small amount of weight if you are overweight and increasing your physical activity.

According to the CDC, a small amount of weight is 5% to 7% of your body weight. For a 200-pound person, this is 10 to 14 pounds.

The Physical Activity Guidelines for Americans, 2nd edition also recommends that people get at least 150 minutes of moderate-intensity physical activity each week. In addition, they should aim for muscle-strengthening activities on two or more days a week.

Because prediabetes and diabetes are progressive conditions — getting worse with time if left unchecked — Weisenberger said it’s important to ”take action now, and develop the habits you need to be consistent.”

In addition to spending more time moving and less time sitting, she suggests eating balanced meals filled with non-starchy vegetables such as broccoli, carrots, celery, peppers, tomatoes and zucchini.

She also recommends reducing your intake of what she calls “extra” foods, such as sweets, fried foods, and beverages with lots of added sugar.

“There’s so much you can do,” she said. “The list goes on and on.”