Continuous glucose monitoring (CGM) led to slightly improved glycemic control in adults taking multiple daily insulin injections for type 2 diabetes, an industry-funded study found.
Researchers conducted a randomized clinical trial in 158 adults with type 2 diabetes for a median of 17 years (interquartile range, 11 to 23 years), treated at 25 endocrinology practices in North America. Participants were age 35 to 79 years (mean, 60 years), took multiple daily injections of insulin, and had HbA1c levels of 7.5% to 9.9% (mean, 8.5%). They were assigned to CGM (n=79) or usual care (n=79). The primary outcome was HbA1c reduction at 24 weeks. The study was funded by Dexcom, which makes the CGM unit used in the study. Results were published Aug. 22 by Annals of Internal Medicine.
Among the 77 participants completing the trial of CGM, mean CGM use was 6.9 days per week in month 1, 6.7 days per week in month 3, and 6.7 days per week in month 6. Mean HbA1c levels decreased to 7.7% in the CGM group and 8.0% in the control group at 24 weeks (adjusted difference in mean change, −0.3%; 95% CI, −0.5% to 0.0%; P=0.022). The groups did not differ meaningfully in hypoglycemia or quality-of-life outcomes. Severe hypoglycemia or diabetic ketoacidosis did not occur in either group.
The results suggest that CGM may provide benefit to insulin-treated patients with type 2 diabetes as an additional management method, the authors wrote. “A high percentage of the study participants used CGM on a daily or near-daily basis over 6 months with a limited number of visits and phone contacts, none after 3 months prior to the 24-week primary outcome visit,” they said. “Use of CGM was associated with a high degree of patient satisfaction, reduced hyperglycemia and consequently HbA1c levels, and increased time in the target glucose range.”
An editorial noted that less than a year ago, the FDA allowed real-time CGM to replace self-monitoring of blood glucose levels in treatment decisions. “With these data, we should seek to further understand patient populations that will benefit most from CGM intervention, such as those with the skills to address glucose variability,” the editorial stated. Future studies of CGM in patients with type 2 diabetes should look at other health outcomes, cost, and effects in particular subgroups, such as those with higher risk for hypoglycemia, according to the editorial.