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New study published in JAMA shows people with Type 2 diabetes on basal insulin benefit from real-time continuous glucose monitoring

First-ever randomized trial shows CGM is beneficial for millions of people with Type 2 diabetes on less intensive insulin regimens

June 2, 2021

June 02, 2021 – Minneapolis – A randomized clinical trial published in the Journal of the American Medical Association (JAMA) found that use of a real-time continuous glucose monitor improves the way people with Type 2 diabetes using basal insulin manage their condition.

The study, led by HealthPartners Institute’s International Diabetes Center, will also be presented during the 14th International Conference on Advanced Technologies & Treatments for Diabetes (ATTD) at 2 p.m. CT on June 2, 2021.

Key findings from the study include:

  • At the end of the 8-month study, 63% of patients using CGM to guide therapy adjustments had an HbA1c less than 8.0% compared to only 39% of patients using finger-stick glucose reading, a relative increase of 62% (P<0.001).
  • After eight months, the group using CGM to guide therapy and lifestyle adjustments also had significantly lower HbA1c levels (9.1 to 8.0%) than the group of patients using traditional finger-stick glucose monitoring (9.0 to 8.4%). The adjusted difference in mean change in HbA1c was −0.4%, 95% CI –0.8% to −0.1%, P=0.02.
  • Remarkably, the group of patients using CGM spent an average of 3.8 hours more each day within the optimal range of blood glucose levels (70-180 mg/dL) and 3.6 hours less each day in the very high glucose range (>250 mg/dL), while also having a reduction in hypoglycemia compared with the finger-stick glucose monitoring group.
  • Adherence and satisfaction also were very high among the CGM group.

“Just because people are using background insulin doesn’t mean they have control of their diabetes,” said Thomas Martens, MD, an internal medicine physician and lead author on the study. “This is the first randomized controlled study to clearly show that CGM can be a key tool in allowing people with Type 2 diabetes using background insulin to understand and effectively respond to their changing glucose levels.”

The DexCom G6 CGM device used in the study includes a small sensor inserted on the skin that measures the body’s sugar (glucose) level every 5 minutes and transmits the values wirelessly to a compatible smart device or receiver. This gives patients real-time glucose data without the need to prick their finger. The system also offers customizable alerts and alarms to help avoid potentially dangerous low and high blood sugars and a function that allows patients to share their glucose levels in real time with remote followers.

Study Design

  • The study included 175 adults across 15 clinical sites with Type 2 diabetes age 30 years or older who were receiving diabetes care from a primary care provider. The Jaeb Center for Health Research in Tampa, Fla. coordinated the study. DexCom, Inc funded the study and supplied the Dexcom™ G6 Continuous Glucose Monitoring System® used in the trial.
  • All participants had been trying to manage their diabetes using one or two daily injections of long-acting basal or background insulin, which helps regulate blood glucose levels overnight and between mealtimes, but not using faster-acting insulin at meals.
  • Two-thirds of the trial participants were assigned to use CGM. The remaining one third of the trial patients were assigned to use the traditional blood glucose meter, which requires finger-sticks to read glucose levels. Both groups had regular meetings with the study team to discuss their glucose data. However, medical management was provided by the participant’s usual primary care provider, who was responsible for making diabetes treatment changes based on the study team’s recommendations.

“The data that we have for Type 1 diabetes and Type 2 diabetes patients using multiple daily insulin injections show that CGMs are very helpful, but until now we were unsure of the benefit for people with Type 2 diabetes who were on less complicated background insulin regimens,” Martens said. “This data expands the number of people who could benefit from these devices, and points to a possible future in which CGMs are common in primary care clinics across the U.S.”

Roughly one third of the 34 million people living with diabetes in the U.S. use insulin to help manage their diabetes. For those with Type 2 diabetes, the majority are using daily background insulin along with other medications, instead of more complicated regimens which involve a variety of insulin injections multiple times per day. Patients who lower their HbA1c from 9.0 to 8.0% or less have a dramatically lower risk of eye, kidney, heart and nerve complications that are associated with unmanaged Type 2 diabetes.

About International Diabetes Center (IDC)

IDC provides world-class diabetes care, education, publications and research that supports people with diabetes and their families. It is part of HealthPartners Institute which annually conducts more than 400 research studies, and trains more than 700 medical residents and fellows and 1,200 medical and advanced practice students. Its integration with HealthPartners’ hospitals, clinics and health plan strengthens the Institute’s ability to discover and develop evidence-based solutions and translate them into practice. Based in Minneapolis, the Institute’s work impacts care, health and well-being across the region and nation as well as internationally. Visit for more information.

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