A New Glucose Monitor Could Help People With Type 2 Diabetes Who Don't Use Insulin
Guest Contributor
Continuous glucose monitoring has transformed life for many people who live with type 1 diabetes or use insulin for type 2 diabetes. A new study published in the New England Journal of Medicine now asks an important question that affects millions of people worldwide: can continuous glucose monitoring in non insulin treated type 2 diabetes make a meaningful difference too?
This 26 week trial looked at adults with type 2 diabetes who were not using insulin and were receiving care in typical primary care practices across the United States. The study compared two groups. One group used continuous glucose monitoring, often referred to as CGM, while the other received what the authors called routine care. Everyone had type 2 diabetes with room for improvement in blood sugar control, reflected in their starting glycated hemoglobin levels, also known as A1c.
Glycated hemoglobin is a key marker in diabetes care because it reflects average blood glucose over roughly three months. In this trial, the participants started with mean A1c values close to 8.8 percent in the CGM group and 8.7 percent in the routine care group. Those numbers suggest blood glucose levels that are above most commonly recommended targets, so there was clear potential to see whether a new approach like CGM could help.
Over 26 weeks, the results were striking. People in the CGM group reduced their mean A1c from 8.8 percent at baseline to 7.2 percent by the end of the study. In the routine care group, the A1c fell from 8.7 percent to 8.0 percent. Both groups improved, which fits with the idea that attention to diabetes management itself can help. However, the magnitude of change was quite different. After adjustment, the mean difference between groups was a reduction of 0.9 percentage points in the CGM group compared with routine care, with a 95 percent confidence interval from negative 1.1 to negative 0.6 and a P value below 0.001. That statistical language indicates that the advantage for CGM was both sizable and unlikely to be due to chance.
While A1c is an essential marker, continuous glucose monitoring also opens a window into daily patterns that standard lab tests cannot reveal. A particularly important measure is time in range, which reflects the proportion of time glucose values stay within a defined target window. In this study, the range from 70 to 180 milligrams per deciliter served as that goal. The investigators reported that the mean percentage of time in this range was 21 percentage points higher with CGM than with routine care. The confidence interval for that difference ran from 16 to 26 percentage points, and the P value was again less than 0.001, which supports both clinical and statistical significance.
I found this detail striking because time in range is closely linked to how people feel day to day. Spending more time in a safe and steady zone can mean fewer energy crashes, clearer thinking, and potentially a lower risk of long term complications. The improvement seen with continuous glucose monitoring in non insulin treated type 2 diabetes suggests that better information about daily glucose swings may help people and their clinicians make more effective lifestyle and medication decisions even without insulin.
Another key concern with any diabetes therapy is hypoglycemia. When more intensive glucose control is encouraged, there is a natural question about whether the risk of low blood sugar rises as a tradeoff. The researchers examined the percentage of time that glucose values dipped below 54 milligrams per deciliter and also below 70 milligrams per deciliter. For values below 54, they found a between group difference of negative 0.17 percentage points with a confidence interval from negative 0.27 to negative 0.11. For values below 70, the difference was negative 0.20 percentage points with a confidence interval from negative 0.43 to negative 0.09.
These differences were evaluated first for noninferiority, which asks whether CGM is at least not worse than routine care regarding low blood sugar risk. The P values supported noninferiority, and for the threshold below 70 milligrams per deciliter the result also met criteria for superiority with a P value of 0.004. In more everyday language, the study suggests that people using CGM did not spend more time in low blood sugar ranges, and in some respects may have had even less exposure to mild hypoglycemia compared with those receiving routine care. Notably, no severe hypoglycemia events were reported in either group during the trial.
The study enrolled 145 participants in the CGM group and 138 in the routine care group, with ages ranging from 21 to 84 years. All participants were managed in primary care settings rather than in specialized endocrinology clinics. That detail matters because it mirrors the reality for many people with type 2 diabetes, who receive most of their care from primary care clinicians. By focusing on non insulin treated type 2 diabetes, the trial addressed a population that has often been underrepresented in CGM research despite its size.
The investigators also designed their analysis to account for multiple comparisons among key CGM measured secondary outcomes. These outcomes were tested hierarchically to control the type I error rate, which helps maintain the reliability of the findings when several related outcomes are studied. Although the abstract does not itemize every secondary result, it highlights time in range and time spent below certain glucose thresholds as central metrics where meaningful differences emerged.
Of course, not every aspect of CGM use appears in a brief abstract. Questions about cost, insurance coverage, user training, and device comfort are important in real world adoption but fall outside the data reported here. The trial was funded by Dexcom, a manufacturer of continuous glucose monitoring systems, and registered as the CONNECT trial on ClinicalTrials.gov with the number NCT06601166. Funding sources and potential conflicts of interest are standard details in clinical research and provide transparency so readers can interpret findings in context.
Still, within the information provided, this study adds weight to the idea that continuous glucose monitoring can be more than a tool only for people who use insulin. In adults with non insulin treated type 2 diabetes managed in primary care, CGM use led to a greater reduction in A1c, significantly more time in the target glucose range of 70 to 180 milligrams per deciliter, and no increase in severe hypoglycemia. For clinicians and individuals considering whether to use CGM without insulin therapy, these findings offer evidence that the technology may support better overall glucose control and a lower risk of hyperglycemia, all while maintaining a reassuring safety profile.