- Design
- Randomised controlled trial, 22 primary-care practices
- Population
- 283 US adults with type 2 diabetes not using insulin, mean HbA1c about 8.8%
- Primary outcome
- HbA1c at 26 weeks
- Effect
- Adjusted difference −0.9 percentage points (95% CI −1.1 to −0.6)
The CONNECT trial, published in NEJM on 14 October, randomised 283 adults with type 2 diabetes who were not using insulin, across 22 US primary-care practices, to continuous glucose monitoring or routine care for 26 weeks. Mean baseline HbA1c was about 8.8%.
HbA1c fell to 7.2% with CGM and to 8.0% with routine care, an adjusted difference of −0.9 percentage points. Time spent between 70 and 180 mg/dL was 21 points higher with CGM, time below range was slightly lower, and there was no severe hypoglycaemia in either group.
Guidelines already support CGM for people on insulin. This trial asks whether the feedback alone helps people on oral agents or GLP-1 therapy, and in a primary-care setting with uncontrolled baseline glucose, the answer was yes. The size of the effect is similar to adding a glucose-lowering drug.
The trial was funded by the manufacturer, lasted six months, enrolled people with clearly raised HbA1c and did not measure complications. Cost and sensor access will decide how far this travels, especially in India, where most non-insulin patients pay out of pocket.
- Consider CGM for adults with type 2 diabetes not on insulin whose HbA1c remains well above target.
- Pair any sensor with a plan to review the data together, since the benefit depends on acting on it.
- Teach patients to read time in range and post-meal peaks, not only a single number.
- Recheck HbA1c at three to six months to judge whether the sensor is earning its cost.
- Weigh sensor cost against the alternative of adding another drug, particularly for patients paying themselves.
Why it matters
It challenges the assumption that CGM only pays its way in people who adjust insulin doses.
Don't overread it
Six months of HbA1c data in an industry-funded trial does not show fewer complications or lasting benefit.
The statistics, in plain English
A difference of −0.9 percentage points (95% CI −1.1 to −0.6) is clinically meaningful and the whole interval is well clear of zero. The time-in-range gain of 21 points is roughly five extra hours a day in target. The hypoglycaemia results were tested for non-inferiority first, so they show CGM did not raise low-glucose time rather than proving a large reduction.
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