A New Way to Monitor Blood Sugar

Who can benefit from this wearable technology

- Beth Weinhouse

YOU MAY HAVE noticed them in summer when the weather was warm enough for T-shirts: those square or round, somewhat three-dimensional patches on people's upper arms (though they can be worn elsewhere too). They're too raised to be oestrogen or nicotine patches. So what are they? They're continuous glucose monitors (CGMs), prescribed by physicians for people with diabetes to help them keep track of and control their blood sugar levels. As of this year, one of these monitors, the Stelo biosensor from Dexcom, became available in the US without a prescription, giving new users the chance to improve their health by wearing one.

CGMs measure blood sugar, but they don't actually require blood to do it. The patches cover tiny sensor wires that are inserted (painlessly) just under the skin to check glucose levels in interstitial fluid—the liquid that contains glucose and other substances leaked from blood capillaries. The CGM constantly monitors glucose levels and sends reports to a user's smartphone or other device. These monitors have traditionally been prescribed to people with either type 1 or 2 diabetes who are insulin dependent. The monitor helps people adjust their insulin doses to keep their blood sugar close to normal range. Some of the monitors are even connected to insulin pumps that do the work automatically.