Jessica Castle, M.D., discusses CGM’s A1C impact in non-insulin type 2 diabetes

Adults with type 2 diabetes who don't use insulin lowered their A1C by 0.9 percentage points more with a continuous glucose monitor (CGM) than with routine care over 26 weeks, according to results from the randomized CONNECT trial, published recently in The New England Journal of Medicine.

In this interview with Managed Healthcare Executive, Jessica Castle, M.D., an adult endocrinologist and vice president of global medical affairs at Dexcom, which makes the G7 sensor used in the trial, explains why the population studied in CONNECT is significant. More than 20 million people in the United States live with type 2 diabetes and don't take insulin, Castle said. That makes them the largest treatment group within the most common form of diabetes.

The trial enrolled 283 adults ages 21 to 84 across 22 U.S. primary care practices. It randomly assigned 145 participants to CGM with the Dexcom G7 and 138 to routine care with standard blood glucose meter testing. Participants had a mean age of 60, and 32% were from racial or ethnic minority groups. About 31% had a baseline A1C of 9% or higher. About 37% were taking an SGLT2 inhibitor and 40% an incretin-based medication.

In the CGM group, mean A1C fell from 8.8% at baseline to 7.2% at 26 weeks. In the routine care group, it fell from 8.7% to 8.0%. CGM users spent 21% more of their time in the target glucose range of 70 to 180 mg/dL, or about five more hours per day. They also spent less time with glucose below 70 mg/dL than the routine care group, and no severe hypoglycemia events were reported. CGM users also reported greater satisfaction with glucose monitoring and less diabetes-related distress. A six-month extension is underway to see whether the benefits hold at 12 months.

Lowering high glucose without increasing low glucose was a key finding, Castle said. “Sometimes when you lower high glucose, you can get more low glucose,” she said. “In this case, we saw both of those things get better, which is fantastic because you don't want to trade one for the other.”