The Growing Interest in CGMs for Non-Diabetics

Continuous glucose monitors are medical devices worn on the back of the arm, from which probes are implanted into the interstitial space to constantly analyze glucose levels. These devices have been available for over 25 years, with the original intent to make glucose monitoring easier for diabetics, replacing the need for multiple finger-stick tests throughout each day. 

In 2024, the FDA approved continuous glucose monitors for sale to non-diabetics. Previously, the devices were only available via prescription. The intent of glucose monitoring in non-diabetics is to provide health tracking information. Ideally, this would help individuals make wiser food choices. To provide a few examples, prompting one to eat to avoid low blood glucose levels, identifying foods that greatly elevate blood glucose, and identifying the presence of prediabetes. Is continuous glucose monitoring for non-diabetics worthwhile?

Scientific Considerations and Accuracy for Non-Diabetic Use

Are Continuous Glucose Monitors Accurate?

Continuous glucose monitors have probes implanted in the interstitial space, rather than in the bloodstream, which could potentially lead to differences in glucose values as the samples are obtained from different compartments in the body. Recent research found continuous glucose monitors significantly overestimated glucose levels, especially after meals, when compared to traditional blood testing. Compared to blood measures, continuous glucose monitoring overestimated the time subjects had elevated blood glucose by a factor of 4(!). Further, there was a high degree of interindividual variability between subjects, meaning the continuous monitor tracked well with blood testing for some, but diverged greatly for other subjects. This certainly brings the value of continuous glucose monitoring into question.

Lack of Specific Guidelines and Potential for Misinterpretation

Other potential pitfalls for continuous glucose monitoring in non-diabetics: the ideal blood glucose range for non-diabetics is uncertain, though steps are being made to establish normal glucose parameters for non-diabetics obtained via continuous monitoring. Thus, continuous glucose monitoring could prompt you to eat more than you need to stave off hypoglycemia, or to eschew adequate food intake for fear of making your glucose level too high.

Further, continuous glucose monitoring for a nondiabetic can be viewed in a similar vein as using a fitness tracker. On the good side, continuous glucose monitoring may be helpful in motivating people to achieve higher levels of fitness, and they have been found to be similarly powerful to fitness trackers in helping motivate people to exercise. However, the use of fitness trackers in people prone to body image issues, disordered eating, and/or compulsive exercise fitness trackers have been found to potentially exacerbate unhealthy behaviors. It is likely that CGM could pose the same risk.

In sum, there is no strong case to endorse continuous glucose monitoring for non-diabetics. The accuracy of the data is questionable, and there is potential for the devices to promote unhealthy behaviors. If you suspect you are having issues regulating your blood glucose, I strongly recommend that you first consult with a medical provider rather than using continuous glucose monitoring on your own.

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