Diabetes Dialogue: CONNECT Trial Backs CGM in Non-Insulin Type 2 Diabetes

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Continuous glucose monitoring (CGM) is standard of care in insulin-treated diabetes, but evidence for its use in type 2 diabetes managed without insulin has lagged. New randomized data from the CONNECT trial suggest real-time CGM may substantially improve glycemic control in this much larger population.

On a recent episode of Diabetes Dialogue, hosts Diana Isaacs, PharmD, and Natalie Bellini, DNP, FNP-BC, spoke with Tom W. Martens, MD, of the International Diabetes Center, about CONNECT, recently published in the New England Journal of Medicine.

The trial enrolled 283 adults with type 2 diabetes who were not using insulin or CGM and had hemoglobin A1C levels of 7.5% or higher, across 22 primary care sites. Participants on stable non-insulin therapy were randomized 1:1 to real-time CGM with the Dexcom G7 or to routine fingerstick blood glucose monitoring (BGM) for 6.5 months. Both arms had the same number of brief, mostly virtual visits.

Mean A1C in the CGM group fell from 8.8% to 7.2%, a reduction of 1.6 percentage points. The BGM group improved from 8.7% to 8.0%, for a between-group difference of 0.9 percentage points. This gap is larger than those seen in earlier randomized CGM trials in insulin-treated type 2 diabetes, including MOBILE and DIAMOND.

Randomization was stratified by glucagon-like peptide-1 (GLP-1) receptor agonist use, reported by about 40% of participants at baseline. Among incretin users, A1C fell 1.4 percentage points with CGM vs 0.5 with BGM, the same 0.9-point difference. The benefit also held across other regimens, including sodium-glucose cotransporter 2 (SGLT2) inhibitors, used by about 30% of participants, and sulfonylureas.

More non-insulin therapies were added in the CGM arm. This may reflect access to continuous glucose data in place of infrequent A1C checks, which tend to reinforce clinical inertia. Much of the improvement appeared to come from lifestyle change, as participants could see postprandial excursions and link food choices to their glucose response.

The current American Diabetes Association (ADA) Standards of Care give CGM a grade C recommendation in non-insulin-treated type 2 diabetes. That grade reflects limited trial evidence, not proven lack of benefit. CONNECT may supply the randomized evidence needed for a grade A rating in the 2027 Standards, and payer coverage would likely follow over time.

A six-month extension, in which the BGM group switches to CGM, is still under way. Taken together, the findings suggest CGM adds to the effect of GLP-1 receptor agonists and other non-insulin therapies in primary care.

Editors’ Note: Isaacs reports disclosures with Dexcom, Abbott, Lilly, Novo Nordisk, Medtronic, Insulet, and others. Bellini reports disclosures with Abbott Diabetes Care, MannKind, Povention Bio, and others. Martens reports disclosures with Dexcom, Abbott Diabetes, Sanofi, MannKind, Zealand Pharma A/S, Lilly, and others.

References

1. Oser TK, Martens T, Ruedy KJ, et al. Continuous glucose monitoring in non–insulin-treated type 2 diabetes. New England Journal of Medicine. 2026;395(17):1717-1727. doi:10.1056/nejmoa2608571