In a development that could fundamentally alter the management of Type 2 diabetes for millions of Americans, a landmark study published in the New England Journal of Medicine has provided robust clinical evidence supporting the use of continuous glucose monitoring (CGM) systems for patients who do not require insulin. The study, known as the CONNECT trial and funded by Dexcom, comes at a pivotal moment as the medical community and federal regulators weigh the benefits of expanding access to this technology beyond the traditional insulin-dependent population.
The results of the trial indicate that the use of Dexcom’s G7 CGM system leads to significantly improved glycemic control and behavioral changes among Type 2 diabetes patients managed in primary care settings. These findings arrive as the Centers for Medicare and Medicaid Services (CMS) nears a critical decision regarding the expansion of Medicare coverage for CGMs, a move that could double the number of beneficiaries eligible for the devices and reshape the commercial landscape for diabetes technology.
Detailed Analysis of the CONNECT Study Results
The CONNECT study was designed as a randomized controlled trial involving 440 participants across 22 primary care practices in the United States. This "real-world" setting is particularly significant because the vast majority of patients with Type 2 diabetes are managed by primary care physicians (PCPs) rather than endocrinologists. The participants were randomly assigned to either a group using the Dexcom G7 CGM or a control group receiving routine care, which typically involves periodic finger-stick blood glucose testing and quarterly HbA1c (hemoglobin A1c) lab tests.
At the start of the study, the average HbA1c level—a measure of average blood sugar over three months—was approximately 8.8% for the CGM group and 8.7% for the control group. Medical guidelines generally recommend an HbA1c goal of below 7.0% for most adults to reduce the risk of long-term complications such as kidney disease, nerve damage, and vision loss.
After 26 weeks, the results demonstrated a stark contrast between the two cohorts. Participants in the CGM group saw their HbA1c levels plummet by an average of 1.6 percentage points, reaching a mean of 7.2%. In contrast, the control group saw a more modest reduction of 0.7 percentage points, ending at 8.0%. The 1.6% reduction is considered clinically massive, as every one-percentage-point drop in HbA1c is associated with a significant reduction in the risk of microvascular complications.
Beyond HbA1c, the study measured "Time in Range" (TIR), defined as the percentage of time a patient’s glucose levels remain between 70 and 180 mg/dL. The CGM group spent an average of five additional hours per day within this target range compared to the control group. Furthermore, the data showed a near-elimination of prolonged hyperglycemia (high blood sugar) in the CGM group.
Demographics and Universal Efficacy
One of the most compelling aspects of the CONNECT study was the consistency of its findings across diverse patient populations. Diabetes disproportionately affects minority communities and individuals with lower socioeconomic status, who often face barriers to accessing advanced medical technology.
Dexcom reported that the benefits of the G7 system were consistent regardless of age, sex, race, ethnicity, or body mass index (BMI). Furthermore, factors such as income level, education, insurance type, and the duration of the patient’s diabetes did not diminish the effectiveness of the device. This suggests that the "biofeedback" loop provided by a CGM—where a patient can see in real-time how a specific meal or a walk affects their blood sugar—is a universal tool for behavioral modification.
Dr. Roy Beck, the study’s senior author and medical director of the JAEB Center for Health Research, emphasized the high adherence rates observed during the trial. Nearly all participants continued to use the CGM after 26 weeks, with most utilizing it daily. "The fact that participants incorporated it so seamlessly into their daily management indicates they recognized the immediate benefit," Dr. Beck stated. He argued that these results support the consideration of CGM use much earlier in the progression of Type 2 diabetes, potentially delaying or preventing the need for insulin therapy.
The Regulatory and Reimbursement Landscape
The publication of the CONNECT study is timed to influence a looming decision from CMS. Currently, Medicare coverage for CGMs is largely restricted to patients with Type 1 diabetes or those with Type 2 diabetes who require intensive insulin therapy (typically three or more injections per day) or use an insulin pump. Recently, coverage was expanded to include those on "basal" (long-acting) insulin, but millions of patients who manage their condition through diet, exercise, and oral medications like metformin or GLP-1 agonists remain uncovered.
Market analysts, including Mike Kratky of Leerink Partners, suggest that a positive CMS decision could be reached before the end of 2026, with implementation likely in mid-2027. Such an expansion would be transformative for the industry. Kratky noted that for Dexcom alone, this could double the number of "covered lives"—patients whose insurance pays for the device—from approximately 15 million to 30 million.
Abbott, Dexcom’s primary competitor in the CGM space with its FreeStyle Libre line, has also been vocal about the potential of this market. During earnings calls earlier this year, Abbott executives estimated that a CMS expansion for non-insulin Type 2 patients could add roughly 10 million Medicare beneficiaries to the pool of eligible users.
Economic and Clinical Implications
The shift toward CGM use in non-insulin populations represents a move toward "preventative" technology. While the upfront cost of providing sensors to millions of additional patients is significant, proponents argue that the long-term savings to the healthcare system could be substantial.
By keeping patients in their target glucose range and lowering HbA1c levels, CGMs help prevent the catastrophic and expensive complications of uncontrolled diabetes, such as dialysis for kidney failure, amputations due to neuropathy, and hospitalizations for cardiovascular events. Additionally, the CONNECT study noted "higher medication intensification" among CGM users. This suggests that the data provided by the CGM allowed physicians to make more informed and timely adjustments to oral medications, optimizing treatment plans faster than the traditional "wait and see" approach associated with quarterly lab visits.
The total addressable market is vast. According to analysts at William Blair, approximately 25 million people in the United States have Type 2 diabetes and do not currently use insulin. Providing these individuals with tools to visualize their metabolic health could mark the beginning of a new era in chronic disease management.
Industry Reaction and Future Outlook
The investment community has reacted positively to the "totality of the data" presented in the NEJM. Analysts suggest that the strength of the CONNECT study makes it difficult for regulators to ignore the clinical utility of CGMs for the non-insulin population.
The move also coincides with the rising popularity of GLP-1 receptor agonists (such as Ozempic and Mounjaro). There is a growing consensus among clinicians that the combination of GLP-1 medications and CGM technology provides a "double-edged sword" against diabetes. While the medication assists with weight loss and insulin sensitivity, the CGM provides the data necessary for patients to sustain lifestyle changes.
As the industry awaits the CMS decision, the focus is shifting toward how primary care practices will integrate this technology. The CONNECT study proved that CGMs could be successfully deployed in the PCP environment, but widespread adoption will require streamlined workflows for data review and patient education.
Chronology of CGM Expansion
To understand the significance of this moment, it is helpful to look at the timeline of CGM evolution:
- Early 2000s: CGMs are introduced primarily as a tool for Type 1 diabetes patients to prevent life-threatening hypoglycemia.
- 2017: CMS grants the first coverage for CGMs for Medicare beneficiaries with Type 1 and Type 2 diabetes who require intensive insulin.
- 2023: Medicare expands coverage to include "basal-only" insulin users and certain non-insulin users who experience frequent, severe hypoglycemia.
- 2024-2025: Dexcom and Abbott launch "over-the-counter" or "lifestyle" versions of their sensors (Stelo and Lingo, respectively) aimed at non-insulin users and health-conscious consumers.
- October 2026: The CONNECT study is published in NEJM, providing the definitive clinical backing for the non-insulin Type 2 population.
- Expected Late 2026/2027: Anticipated CMS decision to broaden coverage to all Type 2 diabetes patients, regardless of insulin use.
Conclusion
The publication of the CONNECT study serves as a scientific cornerstone for the next phase of diabetes care. By proving that technology once reserved for the most "severe" cases of diabetes can provide life-changing benefits for those in the earlier stages of the disease, Dexcom has set the stage for a massive expansion of the CGM market. As the healthcare industry moves toward more data-driven, personalized medicine, the real-time insights provided by these wearable sensors may soon become the standard of care for every person living with Type 2 diabetes in America. The decision now rests with federal regulators to determine how quickly that future arrives.
