Should I use a continuous glucose monitor?

Q. I'm overweight, but don't have diabetes yet. Should I use a continuous glucose monitor, like people with diabetes do?

A. Increasingly, new technologies are allowing us to monitor how our body is functioning. Smart watches and specialized rings monitor the number of steps we take and flights we climb, our heart and breathing rates, and our blood oxygen levels.

People with diabetes need to monitor their level of blood sugar, often multiple times a day, to make sure it doesn't get either too high or too low. When I was beginning my medical career, measuring blood sugar levels required a venipuncture (using a needle to take a blood sample). That was not something a patient could do, so instead we asked patients to collect several urine samples a day and use a kit to measure the level of sugar in it. That gave a crude indication of when blood sugars were too high, but didn't help determine when sugars were too low.

Then, new technology allowed people to prick a fingertip, collect a drop of blood on a special test strip, and use a machine to measure the blood sugar level. This was more accurate than the urine testing and much more feasible than multiple venipunctures each day, but people didn't much like pricking their fingertips. Neither did their fingers.

Then came continuous glucose monitoring technology. A small device sticks to the skin, and a tiny sensor on the underside of the device painlessly pushes into the skin. The sensor continuously monitors the level of sugar and sends that information wirelessly to another device (such as a smartphone) where a person can easily see their sugar level. With some devices, an alarm goes off when the sugar is too high or too low. Continuous glucose monitors can be expensive and are not always covered by insurance.

You ask if you should use a continuous glucose monitor, even though you do not have diabetes. There are relatively few studies of that question. At this time, there is no solid evidence of the value of these monitors in people who do not have diabetes.

What will future studies show? I'm much better at predicting the past than predicting the future, but here goes: my bet is that these devices will have no value in people who have no risk factors for diabetes. On the other hand, they may prove to have value in some people who have risk factors for diabetes — such as people who are overweight (like you), people with prediabetes whose blood sugar levels are somewhat high, and people for whom diabetes runs in the family. But this will need to be scientifically established before it's worth using such monitors. Or before insurance is likely to pay for them.

Image: © miodrag ignjatovic/Getty Images