Blood Sugar Levels: When It's a Good Idea for T2Ds to Test Their Glucose

An endocrinologist interprets the findings of a recent study and explains the reasons why some people with type 2 diabetes should test their glucose regularly.

close up of finger prick on black woman's handsIf you have type 2 and consume a lot of food that raises blood sugar, monitoring is a very good way to see the impact of your diet. (Photo: 123rf)

Every day, once or twice a day, I prick my finger, squeeze out a bead of blood onto a strip of special paper, wait five seconds, and record the number that pops up on my glucometer in my blood glucose log.

After many years of living with type 2 diabetes, preceded by two terms of gestational diabetes, it’s become a habit. It’s also something each of my endocrinologists has recommended and encouraged, part of our quest for excellent care.

All of that may be about to change.

A new study has suggested that patients who take no medications for their type 2 diabetes or rely on oral medications like metformin that do not cause hypoglycemia, or too-low blood sugars, may be over-testing their blood sugars.

And that the solution may be to abandon regular testing, period.

The study, published in JAMA Internal Medicine by a research team from the University of Michigan,1 has been supported by The American Academy of Family Physicians, the Society of General Internal Medicine, and the Endocrine Society who issued guidance for physicians stating that these patients don’t need to regularly test their sugars as it may not be a judicious use of supplies such as test strips and glucose meters.

Not included are patients who clearly need to monitor: those who inject insulin and those who take medications that carry a risk of causing hypoglycemia (quinolone antibiotics, beta blockers, quinidine, metformin when added to sulfonylureas, sulfonylureas and alpha glucosidase inhibitors). One limitation of the study that may be important to consider is that it only included people with private insurance.

While I have cut back on my monitoring over the years from three or four times a day to one or two, I find myself—despite the recommendation—not completely comfortable with abandoning the practice. It may simply be from habit, but staying alert to how food, exercise and metformin impacts my daily sugars has been essential to my staying in good control.

And while I know metformin doesn’t cause lows, there are times when—after strenuous exercise or missing a meal—I’ve experienced “relative hypoglycemia,” a sense that  my blood sugars are dropping. The symptoms are similar to hypoglycemia—shakiness, pale skin, hunger.

But a quick fingerstick reassures me that my sugars are in an acceptable range and rather than head for something sweet what I really need to do is rest, drink a cup of water, and stop worrying.

Individualized Care

When it comes to type 2 diabetes, it’s important to remember that care is very individualized, explains Mark Schutta, MD, an endocrinologist at Penn’s Rodebaugh Diabetes Center in Philadelphia. This also applies to glucose monitoring: how often and when people test depends both on a person’s physical condition and how well they are taking care of their disease. 

“The idea that just because you're diabetic, you need to check your sugars two or four times a day, or whatever, isn’t necessary for all patients,” says Dr. Schutta. “Management and recommendations for testing really need to be individualized.”

“A person with type 2 diabetes who is well controlled, stable and using medications that don’t cause low blood sugars—like metformin or DDP-4 inhibitors—who maintains a stable weight and exercise routine and who has had several hemoglobin A1C blood tests  below their target range, probably doesn’t need to monitor much,” he said.

The Value of Regular Testing for Type 2s 

But in other cases, monitoring may prove beneficial.

“For people who consume a lot of food that may raise their blood sugars, monitoring is a great way to demonstrate the impact of certain foods instead of others,” Dr. Schutta says. “For example, if someone tests their sugar before and two hours after their meal to compare the impact of having  a bagel, hash browns and orange juice for breakfast compared to a bowl of oatmeal and yogurt, they can see for themselves the difference in the blood glucose two hours after each meal.”

Also, type 2 diabetes presents differently in different people. Some patients have more erratic or inconsistent control—sometimes high and sometimes low. Keeping track of those numbers can be helpful.

Which Sugars Should Be Checked?

If you’re going to reduce or eliminate taking your blood sugars altogether, you should take into account how you’ve been taking your blood sugars in the past.

“For many patients, who have been told to check their fasting sugars, that’s the only time that they check,” explains Dr. Schutta. “But fasting blood sugars are sometimes dependent on what the patient ate the night before and they don’t always tell the whole story.”

For example, for people who have high hemoglobin A1C’s yet clock reasonably low blood sugars in the morning, checking later in the day— before lunch, dinner and bedtime—may be valuable.

One argument often made for taking blood sugars regularly is that it provides physicians with a more accurate picture of your daily diabetes, since the hemoglobin A1C is really only a three-month average of blood glucose values and may be filled with highs and lows. Dr. Schutta counters that blood drawn A1C tests are quite reliable.

“If a doctor thinks a patient is having many highs and lows—you can figure that out most quickly with most people—you can have them check their blood sugars four or five times a day for a week or two and see where your sugars are going up and down and then we can figure out a regimen,” Dr. Schutta says.

He also noted that blood glucometers can be less than accurate, particularly when compared to continuous glucose monitors (CGMs) which provide a more dynamic picture of blood sugar values over a long period. 

Despite the recommendation of the study, Dr. Schutta recognizes that some patients will want to continue to check their sugars, in part because it makes them feel more secure about their diabetes.

“Every person is different, everybody is comfortable doing different things,” he said. “My goal is to find a plan that a patient is comfortable with that reveals to me what I need to know about your diabetes.”

As for me, I’m going to hold onto my glucometer for now—just in case. Call it a crutch, but it’s served me well.

“You can think of this new information as a reward for people who adopt a good lifestyle and take care of their diabetes,” he said. “The reward is that you can say, ‘Hey, you really don’t need to  fingerstick.’ ”

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