Continuous Glucose Monitoring Improves Type 2 Diabetes Control Without Insulin
A randomized trial found glucose monitoring lowered A1c and added about five daily hours in target range for adults with diabetes not using insulin.
Summary
Continuous glucose monitoring improved blood sugar control in adults with type 2 diabetes who were not using insulin. Researchers randomly assigned 283 adults at 22 U.S. primary care practices to monitoring or routine care for 26 weeks. Average hemoglobin A1c, a measure of blood sugar over several months, fell from 8.8% to 7.2% with monitoring and from 8.7% to 8.0% with routine care. The adjusted difference favored monitoring by 0.9 percentage points. Monitoring also added about five hours daily within the target blood sugar range, without reported severe low blood sugar events. These findings support discussing monitoring with a clinician when diabetes remains above target. However, this abstract-only summary cannot establish long-term benefits, cost-effectiveness, or whether monitoring reduces complications. Dexcom funded the study.
Detailed Summary
Adults with type 2 diabetes often struggle to reach blood sugar targets even when they do not need insulin. Continuous glucose monitoring provides frequent readings that can inform daily decisions and treatment discussions. This trial tested whether that feedback improves blood sugar control in primary care, where many adults receive ongoing diabetes treatment.
Researchers randomly assigned 283 adults at 22 primary care practices across the United States to continuous glucose monitoring or routine care for 26 weeks. Participants were 21 to 84 years old and were not using insulin. The main outcome was hemoglobin A1c, a measure of average blood sugar over the preceding few months.
Average A1c fell from 8.8% to 7.2% with monitoring, versus 8.7% to 8.0% with routine care. The adjusted advantage was 0.9 percentage points, with a 95% confidence interval of 0.6 to 1.1 points. Participants using monitoring also spent 21 percentage points more time between 70 and 180 mg/dL, equivalent to about five additional hours daily.
Time spent below 70 mg/dL was slightly lower with monitoring, and neither group reported severe low blood sugar events. These findings support discussing monitoring with clinicians when diabetes remains above target without insulin. However, the study does not establish benefits for adults without diabetes or demonstrate fewer heart attacks, kidney complications, or deaths. It also does not show that glucose monitoring extends lifespan or replaces established treatments.
This summary is based on the abstract only. Follow-up lasted six months, leaving durability and longer-term health effects uncertain. The abstract does not detail medication adjustments, education, adherence, costs, or participant characteristics beyond age and baseline A1c. Dexcom funded the trial, and several authors were affiliated with the company. Independent replication and fuller reporting would help clarify implementation, affordability, and which patients are most likely to benefit in everyday clinical practice settings.
Key Findings
- At 26 weeks, continuous glucose monitoring lowered A1c by an adjusted 0.9 percentage points more than routine care.
- Monitoring increased time within 70–180 mg/dL by 21 percentage points, equivalent to about five additional hours daily.
- Time below 70 mg/dL was slightly lower with monitoring; neither group reported severe hypoglycemia.
- Adults with type 2 diabetes above their glucose targets despite non-insulin treatment can discuss monitoring with their clinician.
Methodology
The CONNECT randomized trial assigned 283 adults not using insulin to continuous glucose monitoring or routine care at 22 U.S. primary care practices for 26 weeks. The primary outcome was hemoglobin A1c at 26 weeks; key glucose-monitoring secondary outcomes were tested hierarchically to control false-positive findings.
Study Limitations
This summary is based on the abstract only, which does not detail medication changes, education, adherence, costs, or broader participant characteristics. The 26-week duration cannot establish durable benefits or reductions in long-term complications. Dexcom funded the trial, and several authors had company affiliations, warranting attention to potential conflicts of interest.
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