If you have diabetes, a key part of taking care of your health is keeping an eye on your blood-glucose levels. But what’s the best way to do this, and what do you do with the numbers? A pair of experts in diabetes tackled these questions at the first of a three-part diabetes education series sponsored by MIT Medical’s Diabetes Care Management Program.
Nearly 30 people attended “Monitoring Matters: How to Reduce Your Risks Using Today’s Technology” featuring medical director and endocrinologist William Kettyle, M.D., and Joan Hill, R.D., C.D.E., certified diabetes educator. Most in attendance have diabetes or pre-diabetes, but when asked for a show of hands by Hill, only a minority were monitoring their blood glucose regularly.
People with diabetes (PWDs) often have a blood-glucose level that is too high because they’ve partially or completely lost the ability to make insulin or to effectively use the insulin they do make (insulin is a hormone needed to metabolize glucose, the body’s fuel).They are also at risk of having their blood-glucose levels become dangerously low if they go too long without eating or are unknowingly taking too much insulin or other medication.
“The brain needs a constant supply of glucose, just like it needs oxygen,” Kettyle explained. But too much glucose in the blood over time can lead to complications of diabetes including heart disease and other circulation problems, vision loss and nerve damage.
Technology has advanced
Years ago, the only way to check one’s glucose level was with either a urine sample or having blood drawn at a lab, Kettyle explained. Self-monitoring kits now allow patients to get a blood sample from a finger prick and use a test strip along with a small electronic device to check their blood glucose whenever they want. They can see average readings over time, download the data onto a computer and create charts, and share the data with a health-care provider.
What used to be called “home-monitoring kits” are now called self-monitoring kits “because you can and should be doing blood glucose monitoring anywhere — in a restaurant, at your mother-in-law’s house, at a county fair,” Hill said.
Some PWDs use continuous glucose monitoring, where a small catheter is inserted under the skin to measure glucose in the interstitial fluid. These monitors sound an alarm if blood glucose levels become too low or too high.
Another important tool for PWDs is glycohemoglobin monitoring. This test, also called A1C, looks at red blood cells, which become glycated when they react with glucose molecules in the bloodstream. The higher the proportion of red blood cells that are glycated, the more glucose there is in the blood. A healthy target for a PWD is 7 percent; studies have shown that patients with higher levels develop diabetes complications more quickly, Kettyle said.
Patients can monitor their blood glucose any time of the day, though the most important time is right after waking up, when a normal “fasting” blood glucose level is 80-120 milligrams of glucose per deciliter of blood, Kettyle said. Another good time to check is just before other meals, to see if the blood glucose level has returned to a normal range after the previous meal (it can go as high as 300-400 mg/dl an hour or two after eating, which is dangerously high, he noted).
Pricking your finger several times a day “is not a fun thing to do,” but even if you’re not insulin-dependent, a period of frequent testing is useful for seeing how your blood glucose rises and falls over the course of a normal day, Kettyle said. Alternatively, a patient could check blood glucose just once a day, but he or she would have to be sure to do it at a different time of day over a longer period of time to get this daily pattern information, he added.
Eating and exercise
As for eating habits, Kettyle said it’s better to eat several small meals at regular intervals throughout the day (plus snacks if desired) rather than getting most of your calories at one meal. “The best way to use a stressed metabolic system is continuous grazing — putting a little bit into yourself all the time,” he said.
Patients with pre-diabetes should monitor their blood glucose levels at whatever frequency their provider recommends. “Diabetes isn’t exactly one point in time; people ramp up to it,” Kettyle said. Factors that people at risk for diabetes need to be aware of include age, weight, diet, exercise levels, family history, pregnancy and medications being taken for other conditions.
Controlling weight, diet and exercise are things that all patients can do, and it’s more effective than medication at delaying or preventing full-blown diabetes from developing, he said. Even a modest amount of walking or weight loss can help, and for those who are less mobile, chair-based exercises are useful as well.
What the future holds
Researchers at MIT and other places are working on new ways to monitor blood glucose without having to draw any blood, Kettyle said. One idea is for a “tattoo” of glucose-detecting nanoparticles which are injected just below the skin; a wristwatch-like device held over the area would display the patient’s glucose levels. Another team is working on a way to detect glucose levels by scanning the arm or finger with near-infrared light.