Type 2s Need Blood Sugar Test Strips
Should patients with type 2 diabetes test their blood glucose (BG) levels?
The American Diabetes Association recommends BG testing for all patients. But British researchers Andrew Farmer and colleagues announced at the June meeting of the American Diabetes Association that BG monitoring in type 2s resulted in no change in hemoglobin A1c results and suggested that the costs would be better spent “supporting other health-related behaviors.”
The announcement set off a feeding frenzy of articles in the news media as well as Internet health blogs, most of them with headlines saying testing in type 2s was not useful. For example: “Not Using Insulin? You May Not Need Home Glucose Tests” or “Blood Glucose Monitoring for Non-Insulin Users Shows No Benefits.”
Like most media soundbites, or “blogbites,” many of the stories were brief oversimplifications of Farmer’s study, and they didn’t point out any of the caveats from the full paper in the British Medical Journal (BMJ).
Farmer’s study, called the DiGEM study, isn’t the first to tackle this question. There have been numerous previous studies, some showing a significant benefit of testing and some showing none. Farmer’s group pointed out the flaws in previous studies and said that their study was sufficiently large and well controlled to show a significant A1c change of 0.5 or greater.
However, anyone taking the time to read the full study will see that the results were much more limited than as reported in the press. For example, the study concluded that testing had no benefit “in reasonably well controlled” type 2s not using insulin. That’s because the mean A1c of the participants was about 7.5.
A more serious flaw, in my opinion, was the omission of a statement in a 2004 paper describing how the DiGEM study was going to be conducted, noting that “This trial is mainly generalizable to that group of patients willing to be randomised to no self-testing. lt will be limited in its ability to inform management of people who are enthusiastic about regular meter use.”
This caveat was never mentioned in the 2007 BMJ paper reporting the results. That means that even a person reading the full 2007 BMJ paper very carefully would not come across this statement. And how many readers (except compulsive diabetes bloggers) when reading a news story saying that type 2s don’t need to test anymore are apt to go on the Internet and dig out an old study reporting nothing but methods?
This caveat is because the study excluded all those who were already testing their BG regularly. So basically, the study recruited people who weren’t particularly motivated to test their BG and who probably weren’t particularly motivated to do much self-care of their diabetes at all!
The “intensive treatment” group were instructed to test three times a day, two days a week. Even with this relatively low testing frequency, only 52% maintained this level of testing throughout the 12-month study, again suggesting a lack of interest in self-care.
So now we already have two limitations of these results: they only apply to “reasonably well-controlled” type 2s, and they only apply to those not particularly interested in testing. The headlines suggest the results apply to all type 2s not on insulin.
But wait! There’s more!
Nowhere in either the 2007 or the 2004 article does it describe exactly what instructions were given to the “more-intensive self-monitoring” group. The papers simply say that they were “given training and support in timing, interpreting, and using the results of their blood glucose test to enhance motivation and to maintain adherence to diet, physical activity, and drug regimens.”
“Adherence motivation”? “Maintain adherence”? It sounds to me as if they set BG goals for the patients and then told them, “If your BG results are not in your goal ranges, try harder to adhere to your diet and exercise program.” In other words, I suspect that the patients were not told to eat less of the foods that made their BG levels go up. It was assumed that they wouldn’t follow their prescribed diets, and the goal was to make them more compliant.
If the patients were on a typical American Diabetes Association low-fat diet with 60% carbohydrate, and if they’d slipped off the wagon and started filling up by eating more meat and cheese and olive oil, then being more compliant would mean eating less fat and more carbohydrate, which would likely make their BG levels go up, not down.
So it’s not surprising to me that the intervention had no positive effects.
Has any researcher ever studied type 2s who are told to test their BG levels and then modify their own diets on the basis of their postprandial BG results? If patients see that white bread and rice make their BG levels increase but chicken and broccoli do not, motivated patients will eat more chicken and broccoli and less white bread and rice.
Researchers aren’t apt to do such studies, but patients themselves have been doing them informally for years and have been sharing their results through the Internet. “Eat to your meter” is the rule of this group of motivated patients.
The idea is to test before a meal and then test 1 or 2 hours after the meal, or both, to see how each meal affects your BG levels. If the BG levels go up a lot, don’t eat that meal again. If they stay in a good range, then that’s a good choice for you.
One of the best descriptions of this method has come to be known as “Jennifer’s Advice,” and many people coming across this advice have used it to get their BG levels from quite high levels into normal ranges and their A1cs into the 5s, sometimes even into the 4s.
I think most people would agree that there’s no point in testing your BG levels if you don’t do anything with the results. But when the testing results in positive changes, it’s definitely cost-effective for everyone. Test strips are a lot cheaper than dialysis.
What the medical profession needs to do—rather than investing money in large studies and then quibbling about the statistical meaning of the results—is to learn to teach their patients how to use testing to modify their diet and exercise regimens to get better A1cs.
If the patients show no interest in testing, if they show no comprehension of how to use the results, and if the medical staff can’t figure out how to use the results themselves to suggest meaningful changes (more than just “You should really change to a healthier lifestyle” or “You need to follow your diet and exercise plan better”), then it would be reasonable to prescribe fewer strips.
And once a type 2 not using insulin has learned which diet works best fort hat person, the intensive testing that taught the patient how to get good control can be cut back, with only regular spot testing to make sure things aren’t changing.
But even the well-controlled, motivated patient shouldn’t stop testing altogether. I know too many people who thought they were fine because they’d used intensive testing to get their BG levels into the normal range, so they figured they didn’t need to test anymore. Then they gradually started eating a little more of the foods they knew they shouldn’t. Then more. And more. Until their BGs were quite high, and in some cases they had to start on insulin.
Let’s hope the medical profession understands all this and isn’t swayed by newscaster soundbites and cute blogger headlines.
Motivated type 2 patients need test strips if they are to avoid expensive complications that could bankrupt the American health care system.