Continuous glucose monitors are no longer just for people with diabetes. In March of last year, DexCom gained FDA clearance for its over-the-counter CGM, and then a couple of months later, its main competitor Abbott earned clearance for two over-the-counter CGM devices of its own.
The FDA cleared these over-the-counter CGMs for use in people with and without diabetes, but questions still remain about how clinicians and individuals can interpret the data that these devices collect. To explore what CGM data really means outside of diabetes care, researchers at Mass General Brigham in Boston conducted a study. The results, published this week, found that CGM readings align well with standard measures in people with diabetes but are less reliable in those without the condition.
The study examined data from 972 people ages 40 and older. Within this group, 421 people had type 2 diabetes, 319 had prediabetes, and 232 had normal blood sugar levels.
The researchers found that while CGM metrics like average glucose and time in range closely matched standard measures for people with diabetes, these same metrics were less consistent for those with prediabetes or normal blood sugar.
These findings suggest that CGMs may be most useful for tracking short-term lifestyle effects rather than providing a definitive clinical picture, said Dr. Jorge Rodriguez, an internal medicine physician at Mass General Brigham and one of the study’s authors.
He noted that CGMs can help people see how lifestyle factors such as diet, activity and sleep affect glucose in real time.
Dr. Rodriguez said he has witnessed this firsthand, having worn an over-the-counter CGM himself and never having been diagnosed with diabetes or prediabetes.
“There was one day when I ate a soup. I thought I was being healthy by having a soup. Then it turns out the soup had rice noodles. I didn’t know these rice noodles were just going to drive my sugar up — and it was up for quite some time. For some reason, I didn’t register that this was not a great thing to eat from a glycemic standpoint. That was a learning point for me,” he explained.
He pointed out that further research is needed into consumer-oriented CGMs.
Mass General Brigham’s study was cross-sectional, meaning that the research team gathered data from participants at a single point in time rather than following them over months or years. Dr. Rodriguez said clinicians need more longitudinal research before they understand if CGM patterns in non-diabetic patients can predict long-term outcomes like diabetes, heart disease, or stroke.
Photo: Yana Iskayeva, Getty Images
