Should we now recommend continuous glucose monitoring to all our patients, even those without diabetes? Most of us would instinctively say “no” to this question, but we are seeing opinions from doctors recommending it, and in recent years, scientific literature has focused on the subject.
Today, anyone can get an arm patch that continuously measures interstitial glucose, which is closely related to blood sugar. The information can be read on a dedicated reader or on a mobile phone by scanning the patch or, with some models, without even doing anything.
There is a consensus for prescribing continuous glucose monitoring for patients with type 1 or type 2 diabetes who are treated with at least three insulin injections. Not only is the use of continuous glucose monitoring much more comfortable than self-monitoring with finger sticks, but continuous monitoring also helps reduce glycosylated hemoglobin while decreasing the risk for hypoglycemia. Recently, another indication has begun to be reimbursed in France: Type 2 diabetes under mono-insulin injection when the diabetes is not well controlled.
But alongside these situations, there are two questions that are worth considering.
Untreated Type 2 Diabetes
First, is continuous glucose monitoring desirable for all patients with diabetes, even those not treated with insulin and even when blood sugar levels are well managed? Intuitively, one might think that it can’t hurt and that continuous monitoring of blood sugar can only improve things. We have some evidence supporting this idea, but the level of proof is quite weak. It is not clear that continuous monitoring can improve patients’ awareness of the impact of dietary choices or physical activity on blood sugar. Obviously, one can imagine that continuously monitoring glucose will encourage a shift toward more beneficial behaviors. But honestly, today, we do not have proof that wearing a continuous glucose monitor can improve behaviors in patients with type 2 diabetes who are treated with noninsulin antidiabetic medications.
Furthermore, a significant study has shown that while the effectiveness is more evident in patients treated with insulin, strong evidence suggests that continuous glucose monitoring could also reduce glycosylated hemoglobin in patients with type 2 diabetes who are not treated with insulin. A close examination of the results suggests that the benefits generally are less than those observed in insulin-treated patients with diabetes.
When we look at the scientific literature, two factors seem particularly important to consider if choosing to prescribe a continuous glucose monitoring sensor. The first is the method used, because the results can vary depending on the method. It appears that only self-monitoring that allows the patient to follow glucose in real time is effective, unlike blind monitoring that allows only a retrospective analysis of blood sugar levels. In the latter case, the patient wears the sensor, and after a week, 10 days, or 15 days, the results are analyzed, possibly with a health care provider. It seems that this is not very effective in improving glycosylated hemoglobin and dietary and physical activity behavior.
The second essential factor to consider is the need for an education program for the use of these sensors to be helpful. If sensors are used but nothing else is done, it does not seem logical. Seeing blood sugar levels without being able to understand them and act accordingly seems of little use. Scientific literature seems to confirm this idea.