New data continued to show clinical benefits from continuous glucose monitoring (CGM) in people with type 2 diabetes, including those who don’t use insulin.

Use of CGM is now considered standard of care for people with type 1 diabetes. Use in type 2 diabetes is growing among those who use insulin, for whom the devices are covered by Medicare and increasingly by other payers. Yet, overall use in type 2 diabetes remains low.

New data from multiple studies presented at the Advanced Technologies & Treatments for Diabetes (ATTD) meeting held in Florence, Italy, on March 6-9, 2024, demonstrated improved glycemic control and other cardiometabolic measures, reduced healthcare resource utilization, and reduced mortality among people with type 2 diabetes who use insulin. Some data also showed similar improvements among those not using insulin.

“All of the big datasets are showing the same signal. Hemoglobin A1c goes down, healthcare resource utilization goes down, and it doesn’t matter which therapy is used. CGM seems to be effective for all patients with diabetes,” ATTD Session Speaker Irl B. Hirsch, MD, professor of medicine at the University of Washington, Seattle, Washington, told Medscape Medical News.

Another presenter, Peter D. Reaven, MD, professor of clinical medicine, The University of Arizona College of Medicine – Tucson, told Medscape Medical News, “Use of CGM may have impacts on lifestyle behaviors, leading to improved dietary and exercise patterns. These type of lifestyle changes would typically be beneficial in type 2 diabetes on all treatment regimens.”

However, Hirsch said, “Reimbursement is quite patchy. The patients I’m most concerned about are those in the [US] states that don’t have Medicaid expansion. There are large numbers of people who could benefit from CGM, both type 1 and type 2, who don’t have access. Where I live, as a rule of thumb there is good but not perfect access for those taking insulin and poor coverage for those not requiring insulin.”

Asked whether he believes CGM will become standard of care in treating type 2 diabetes, Hirsch replied, “If the price comes down, yes, but we aren’t there yet.”

What’s Behind the Improvements?

William H. Polonsky, PhD, a clinical psychologist who leads the Behavioral Diabetes Institute in San Diego, California, presented qualitative data demonstrating what’s behind the improvements with CGM in people with type 2 diabetes.

His team conducted in-depth, semi-structured interviews with 34 adults with type 2 diabetes who had been using CGM for 3-6 months. All had received the devices free through a local program but hadn’t received guidance as to how to use the glucose information the devices provide. Half were using insulin, and the rest were not.

At 3 months, A1c dropped from 9.2% to 7.2% “without a lot of guidance or support,” Polonsky commented.

Several themes emerged from the interviews. One, Polonsky called “Making the Invisible Visible.” In one example, a patient said “Before CGM, I was just guessing. I had somewhat of an idea, but I didn’t really know for sure what different foods did…CGM has brought so much insight into what different foods do to my system.”

A second theme was “effective decision-making is now possible.” This was exemplified by a patient who said “I’ve learned that when I eat something and it goes high, that’s something I shouldn’t eat. If I eat vegetables, it stays flat. Same with protein. Basically, the problem is carbs or straight sugary foods. The dietician tried to tell me this before. It would go in one ear and out the other. I didn’t believe her. I believe her now!”

And the third theme, “Enhanced Self-Efficacy,” led one participant to say “I am more in control of my diabetes now with the CGM. Before, diabetes was controlling me, and it was really out of control. Now that I’m back in control, I feel mentally a lot better.”

Polonsky noted, “You get these very consistent themes across our 34 participants.”

The participants took actions based on the CGM data. All 34 (100%) reported making dietary modifications based on CGM readings, 32% reported changing their physical activity, and 28.5% changed their medication use.

“This study highlights CGM’s potential to bring about meaningful change in the type 2 diabetes population,” Polonsky concluded.

Healthcare Resource Use Among Medicaid Beneficiaries Drops With CGM

Hirsch presented data from studies funded by Abbott Diabetes Care comparing healthcare resource utilization of Medicaid beneficiaries 6 months prior to CGM use with that seen 6 months after CGM initiation, in two separate claims data analyses. On March 7, 2024, he presented data for 9574 patients with type 2 diabetes using only basal insulin, followed on March 9, 2024, by an analysis of 35,367 using multiple daily injections (MDIs).

In the basal insulin group, the number of inpatient hospitalizations dropped by 18%, from 0.37 pre-CGM to 0.31 post-CGM; emergency department (ED) visits by 12%, from 0.95 to 0.84; and outpatient visits by 6%, from 9.11 to 8.6. All those differences were statistically significant at P < .001.

However, among those with low utilization (one to two vs ≥ three visits) pre-CGM, outpatient visits increased by 123%, from 1.6 to 3.57, likely because seeing the CGM numbers led them to seek more assistance, and/or their treatments had changed, requiring more visits for adjustments, Hirsch hypothesized.

Similarly, in the MDI cohort, the number of hospitalizations, ED visits, and outpatient visits pre-and post-CGM dropped by 28%, 17%, and 7%, respectively, again all significant at P < .001. And again, the initial low utilizers had more outpatient visits with CGM, 112% (P < .001), but the high utilizer group showed a reduction.

“This suggests that CGM may lead to more efficient use of healthcare resources. The reductions in hospitalizations and emergency department visits may translate into overall cost savings. We need to do those analyses,” Hirsch concluded.

Mortality Reduction, Other Benefits Seen in Insulin-Treated

Reaven, who is also a staff endocrinologist at the Carl T. Hayden Veterans Affairs Medical Center, Phoenix, Arizona, presented the first-ever CGM mortality data, using VA medical records from 2015 to 2020. In the VA, CGM is covered for veterans who use multiple daily insulin injections or a pump.

The study sample with type 2 diabetes included propensity-matched groups of 15,706 CGM users and 25,180 nonusers. The mortality hazard ratio was 0.86, significant at P < .001. A corresponding analysis of veterans with type 1 diabetes showed an even greater risk reduction, 0.43 (P < .001). The mortality reductions remained “robust” across several different sensitivity analyses, Reaven noted.

A smaller subset analysis showed that the mortality reductions in type 2 diabetes with CGM were more commonly for nonatherosclerotic than atherosclerotic causes.

The number needed to treat over 18 months to prevent one death was 77 for the type 2 group. By comparison, that number for statins ranges from 50 to 130 over 5 years, he pointed out.

Longer-term data of CGM use in insulin-treated type 2 patients were presented by Nanna Lind, a PhD student at the Steno Diabetes Center in Copenhagen. In the 12-month, parallel, open label, randomized clinical trial, 40 adults with type 2 diabetes and A1c of 7.5% (58 mmol/mol) or greater were randomized to CGM and another 36 to fingerstick blood glucose monitoring (controls). The majority (83%) were on basal insulin only and the rest on MDI.

The primary outcome, difference in change in time in range at 12 months as measured by 10-day blinded CGM, was 15.2% greater with CGM (P = .006). Significant reductions with CGM compared to blood glucose monitoring also occurred in A1c (−9.4 mmol/mol; P = .002), total daily insulin dose (−10.6 units/d; P = .026), body mass index (−1.1 kg/m²; P = .006), and body weight (−3.3 kg; P = .004).

Patients in the CGM group also reported greater diabetes-related health, well-being, and satisfaction. “The findings support the use of CGM in the insulin-treated subgroup of type 2 diabetes,” Lind concluded.

Benefits Seen in Type 2 Diabetes, With or Without Insulin

Richard M. Bergenstal, MD, executive director of the International Diabetes Center of HealthPartners Institute, Minneapolis, Minnesota, presented findings from Dexcom’s “Clarity” app cloud for 6641 people with self-identified type 2 diabetes not treated with insulin, using the Dexcom G6, and with baseline time in range of 70% or below.

By 6 months, their mean glucose levels dropped from 201.7 mg/dL to 182.7 mg/dL (P < .001), their glucose management indicator (an approximation of A1c based on CGM data) from 8.1% to 7.7% (P < .001), and time in range 70-180 mg/dL from 41.05 to 56.5% (P < .001). The benefits were equally similar in both younger and older age groups, Bergenstal said.

More real-world data were presented by Stefanie Lanzinger, PhD, of the German Center for Diabetes Research, Ulm University, Germany. The source was the prospective Diabetes Prospective Follow-up Registry, which includes 521 participating centers in Germany and Austria.

Among 2516 adults with type 2 diabetes who used CGM and for whom baseline and follow-up information was available, 15% were using basal insulin alone, 37% basal-bolus, and 48% were not using insulin.

From baseline to 6 months after CGM initiation, A1c dropped from 6.9% to 6.8% among those not using insulin (P < .001), from 7.2% to 6.8% among those on basal insulin only (P < .001), and from 7.5% to 7.3% (P < .001) for the basal-bolus group.

Other improvements were significant only in the noninsulin treated group, including reductions in body mass index (P < .001), systolic blood pressure (P < .001), and total cholesterol (P = .002).

“CGM might be recommended to people with type 2 diabetes irrespective of their treatment, but further studies are needed from other real-world settings to support these results,” Lanzinger concluded.

Hirsh received research support from Dexcom, Tandem, and Mannkind and does consulting for Abbott, Roche Hager, and Vertex. Reaven received research support from Dexcom and the Veterans Affairs Department of Research and Development. Lind received lecture fees from Novo Nordisk and Boehringer Ingelheim, and the Steno2Tech study she reported received CGM equipment from Dexcom. Lanzinger had no disclosures. Polonsky is a consultant for Dexcom, Abbott Diabetes, Eli Lilly, Sanofi, Novo Nordisk, Bigfoot, Insulet, Vertex, and Embecta and received research support from Dexcom and Abbott.

Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape Medical News, with other work appearing in the Washington Post, NPR’s Shots blog, and Diatribe. She is on X: @MiriamETucker.