Benefits of CGM for Diabetes

Continuous glucose monitoring (CGM) has now been available to people with diabetes for more than a decade, but many people with diabetes don’t have any personal experience with this technology. It’s not difficult to understand why this is the case — unless you use an insulin pump, the idea of wearing a device on your body at all times is probably unfamiliar and possibly off-putting. In fact, by one estimate, only 6% of people with Type 1 diabetes who self-inject insulin wear a continuous glucose monitor — and the rate is probably even lower for Type 2 diabetes.

But two new studies show that at least for Type 1 diabetes, people who self-inject insulin may want to consider CGM. Published last month in the journal JAMA, the first study included 158 people with Type 1 diabetes who were randomly assigned to either their usual care (using a traditional “fingerstick” blood glucose meter several times a day), or to wear a continuous glucose monitor for 24 weeks. At the beginning of the first study, the average HbA1c level (a measure of long-term blood glucose control) of participants was 8.6%.

As noted in a MedPage Today article on both studies, after 12 weeks of the first study, members of the CGM group had reduced their HbA1c by an average of 1.1%, and after 24 weeks, the average drop was 1.0%. (In the second half of the study period, members of the CGM group were slightly less likely to wear their monitors.) This compared with an average drop of 0.4% in the control group, showing that CGM made a significant difference in outcomes.

Perhaps even more important, hypoglycemia (low blood glucose) was less frequent in the CGM group, averaging 43 minutes per day compared with 80 minutes in the control group.

The second study — which had a similar design, and also looked at the effect of CGM on people with Type 1 diabetes who self-inject insulin — showed a slightly less dramatic effect of CGM on HbA1c levels, with about a 0.43% difference between the two groups after 26 weeks (versus 0.6% in the first study). But adding to this positive result, CGM users reported less fear of hypoglycemia and a higher level of satisfaction with their treatment than those who continued to receive their regular care.

The authors of both studies noted that contrary to their expectations — and certain previous studies — participants were very good, overall, about wearing their continuous glucose monitors, even though they weren’t used to wearing medical devices. This indicates that CGM might be a good fit for a broader segment of the diabetes population than just people who use insulin pumps. It remains to be seen, though, how willing insurance companies will be to pay for the treatment in people who self-inject insulin.

What’s your take on these studies — if you self-inject insulin, would you be willing to wear a continuous glucose monitor? In your view, are better blood glucose control and less fear of hypoglycemia worth the hassle of wearing a sensor and carrying a CGM or compatible smart device? Should insurance companies pay for CGM for anyone who injects insulin, and wants to try the technology? Or should there be strict medical requirements to keep insurance costs down? Leave a comment below!