A 26-week randomized trial found that continuous glucose monitoring improved glucose control in adults with type 2 diabetes who were not using insulin. The result supports considering CGM earlier in diabetes care, but the study tested one manufacturer’s device in people whose average starting HbA1c was high; it does not show that every non-insulin user needs a monitor.
What changed
At 22 U.S. primary-care practices, 283 adults aged 21 to 84 were assigned to unblinded CGM or routine care. Average HbA1c fell from 8.8% to 7.2% with CGM and from 8.7% to 8.0% with routine care. The adjusted between-group difference was 0.9 percentage points. Participants using CGM spent 21 percentage points more time—about five additional hours per day—in the 70–180 mg/dL range. No severe hypoglycemia occurred.
How strong is the evidence?
This was a multicenter human randomized controlled trial with a prespecified HbA1c primary outcome and hierarchical testing of key CGM outcomes. Randomization strengthens the causal inference that access to real-time glucose information improved these surrogate markers over six months.
What remains uncertain
Participants and clinicians could not be blinded. The trial did not test heart attacks, kidney complications, mortality, long-term durability, cost-effectiveness, or people whose diabetes was already near target. Dexcom funded the study, supplied the tested G7 system, and employed several authors, making independent replication important.
Why it matters
CGM may help some people connect meals, activity, medication, and stress with glucose patterns before insulin is needed. It is a feedback tool, not a substitute for HbA1c testing or clinician-guided treatment decisions.
Sources
Original study in the New England Journal of Medicine, published October 14, 2026 · CONNECT trial record
Illustrative stock photograph by i-SENS USA on Unsplash; it does not depict the trial participants, the tested device, or study results.
