Rethinking Blood Glucose Checks for Type 2
If you have type 2 diabetes and don’t use insulin, how often do you really need to check your blood glucose levels?
Blood glucose checks are a routine part of diabetes self-management, but for the nearly 75 percent of Americans with diabetes who don’t take insulin, research suggests those checks might be unnecessary. “There’s a growing amount of evidence demonstrating the limited utility for people with type 2 diabetes who are not on insulin,” says endocrinologist Katrina Donahue, MD, MPH, professor and vice chair of research in the Department of Family Medicine at the University of North Carolina at Chapel Hill and one of the leading researchers investigating the issue.
The American Diabetes Association’s 2019 Standards of Medical Care in Diabetes agrees. “In people with type 2 diabetes not using insulin,” say the guidelines, “routine glucose monitoring may be of limited additional clinical benefit.”
But don’t toss out your blood glucose meter and your test strips just yet. The question of whether routine self-monitoring of blood glucose has value remains unsettled. And it leads to other questions. For example: Even if self-monitoring does prove to be unnecessary for many adults with type 2 diabetes not on insulin, might there still be people in this group who would benefit or circumstances that would require self-monitoring?
Yes, according to Marwan Hamaty, MD, an endocrinologist at the Cleveland Clinic who confronts this issue frequently in his practice. “One size does not fit all,” he says.
Donahue’s research is helping guide the conversation about the value of routine self-monitoring. In 2017, she and her colleagues published results of the Monitor Trial in JAMA Internal Medicine. In the yearlong study, 450 adults with type 2—none of whom took insulin—were randomly assigned to one of three groups: The first monitored once daily with a meter and strips provided by the researchers, a second monitored once daily and received educational and motivational messages from their meter right after blood glucose checks, and a third group did not monitor at all.
At the halfway point, the participants who used a blood glucose meter showed significant improvements in their A1C test results. But six months later, when the study ended, that had changed. The three groups were doing about the same whether or not they monitored.
What did these results tell Donahue? “With all the things that people with diabetes need to do, self-monitoring might not be the best thing you could do with your time,” she says. “Instead, that time could be used for making other healthy behavior choices, like diet, physical activity, and taking your medications—things that we know have more benefits.”
Other research, however, has shown that self-monitoring may be beneficial when done in a structured manner. Here’s how it works: You receive a monitoring schedule, usually requiring several checks a day before and after meals, and you are taught how to recognize and manage patterns of highs and lows based on your numbers. Your doctor, in turn, uses your monitoring results to help guide your treatment plan. Recent research indicates that such monitoring can help people with type 2 diabetes whose blood glucose levels were well above their goals.
In a study published in Diabetic Medicine earlier this year, researchers recruited 446 adults with type 2 diabetes who did not take insulin and whose blood glucose was not well managed. They randomly assigned participants to follow a structured monitoring plan or to skip self-monitoring altogether. By the end of the yearlong study, the structured group was three times more likely to have achieved an A1C of 7 percent or less, which the American Diabetes Association considers a reasonable goal for most adults with diabetes. However, the participants most likely to reach that goal were those who’d had diabetes for the shortest amount of time and whose A1C was closer to the goal at the beginning of the study.
The researchers acknowledge that structured monitoring can be burdensome; in fact, a quarter of the more than 100 people who dropped out of the study did so because they could not maintain the study’s routine for the entire year. “You need measurements at several points so that you can start to make sense of the data and then take any action necessary, such as going for a walk, having a smaller portion at mealtimes, and changing medication,” says lead author Sharon Parsons, MSc, of the Diabetes Research Unit at Swansea University in Wales.
Though Parsons and her colleagues followed people for a year, she says that blood glucose monitoring may prove helpful even in the short term, particularly for people who struggle to manage their levels. “Structured self-monitoring of blood glucose is useful to help people understand the impact of food and activity on their glucose levels and so could be used for a short period as part of general diabetes education and/or self-management programs,” Parsons says.
Donahue agrees that structured monitoring can provide some benefits; however, she worries that it may require too much effort for too little benefit. “Is the juice worth the squeeze for this population?” she says. “Structured monitoring requires a lot of testing. If you tend to be poorly controlled, it can bring your blood glucose down, but if you’re moderately to well controlled, the investment of effort may not be worth it in the long term.”
People, Not Populations
Medical studies, such as those by Donahue and Parsons, base their conclusions on evidence gathered from the large number of people who participate in them. Done well, they can help determine what does and does not benefit the average person. But physicians, diabetes educators, and other providers don’t treat averages; they treat individuals with specific needs and circumstances.
“Our decisions need to be patient-centered,” says Kellie Antinori-Lent, MSN, RN, CDE, a certified diabetes educator at UPMC Shadyside Hospital in Pittsburgh. “We need to focus on what the individual is able, as well as willing, to do and what’s going to benefit them.”
Hamaty agrees. In his practice, individual diabetes patients differ too much to make blanket recommendations for all of them. In general, he considers routine monitoring unnecessary for those of his patients who effectively manage their diabetes with diet and exercise or with one or two medications that don’t boost their risk of hypoglycemia (low blood glucose). But monitoring can be essential for people who do take medications that can cause low blood glucose, such as meglitinides, sulfonylureas, and insulin.
Hamaty adds that many people may not notice the symptoms of hypoglycemia in time to prevent such dangerous consequences as a car accident or coma. Routine monitoring, including before getting behind the wheel, could prevent serious hypoglycemic events in people who use such meds.
Meter on Standby
Approaching the issue of blood glucose checks with individualized care in mind is a start. But it’s not the whole story. Just as there’s variation in therapy among people with diabetes, there’s also variation in therapy for each person, depending on circumstances.
Take, for example, a woman with type 2 who keeps her blood glucose in goal range without daily blood glucose checks. She may not need regular self-monitoring to manage her diabetes, but an illness or a new medication might affect her numbers. Meter checks can provide important information to share with her provider.
“If you’re not feeling well, you need to know if it’s your diabetes or if something else is wrong, and monitoring is one way you would be able to assess that,” says Antinori-Lent, who recommends that adults with type 2 who don’t rely on daily glucose checks keep a blood glucose meter on hand, understand how to use it, and know how to interpret the readings. “When you start on a new medication, I think that’s even more of a reason to test.”
There’s a catch: Self-monitoring is only effective if people have been taught how to interpret the results and how to use those results to improve their blood glucose. “To be useful, [blood glucose monitoring] must be integrated into the diabetes self-management plan in a personalized way so that results are meaningful to the individual,” says the American Association of Diabetes Educators’ practice guidelines.
The complexity of this issue demonstrates the important role of diabetes educators. “People with diabetes need to be taught when to monitor more often because in a rapidly changing situation, their A1C is not going to tell the story,” Hamaty says.
To Check or Not to Check?
Donahue and her colleagues conclude their report on the Monitor Trial with the same question. They found that blood glucose monitoring had no effect on the A1Cs of those with type 2 who did not take insulin, and they hope that their findings will inspire both adults with diabetes and providers to regularly engage in conversations about the question.
If you currently monitor, Donahue advises against stopping without first consulting your physician. Should you get the green light to skip the finger sticks, you could save money. In a study published in 2018 in JAMA Internal Medicine, researchers report that glucose test strips cost an average of $325 annually, based on insurance claims.
Hamaty says it’s the rare person who would choose to monitor if a doctor deemed it unnecessary, but it’s very individual. “One patient might get too anxious about knowing their blood glucose and only want to know their A1C,” he says, “while another patient may be very particular about knowing and want to check once or twice a day.”
In the end, patient-centric care matters most.