Why Check Your Glucose? Some “Different Conclusions” from Dr. J

* Special for Diabetes Awareness Month *

My friend and co-author Dr. Richard Jackson of Joslin Diabetes Center often expresses frustration at the things his patients were never told about their diabetes.  Believe it or not, the reasons for checking your blood glucose are high on that list.  He has some great insights to share.  NOTE: For all you Type 1 readers, consider “cutting and pasting” this post for your Type 2 friends and relatives.

A Guest Post by Richard Jackson, MD

Contrary to some who claim otherwise, self-monitoring of blood glucose (SMBG) is widely considered to be one of the most important developments in diabetes care since insulin was first used in 1922.  Using SMBG is a given for patients taking insulin, to provide that valuable information necessary for adjusting insulin doses, as well as interpreting the effects of food and activity on glucose levels.

What about someone with Type2 diabetes, however, who isn’t taking insulin? I’ve always felt is that SMBG is still very important, and I’ve discussed this with my patients.  Your SMBG results can show you the effects of your physical activity and exercise, provide you with information about the glucose impact of meals, warn you if your glucose is too low, and provide an overall idea of how well your glucose is controlled.  This approach makes sense to me, as it does to many others.  However, two recent studies have suggested that this approach is too simplistic; that SMBG doesn’t necessarily provide a net benefit for the patient with Type2 diabetes who is not taking insulin.  If this last statement doesn’t ring true for you, bear with me; I still believe strongly in the benefit of SMBG for patients without insulin, but there are important considerations in how this information is used.  Let me review briefly these two clinical studies, and discuss three important messages they provide.

The DiGEM study followed 453 patients with Type 2 diabetes, not on insulin, for three years, dividing them into 3 groups: no SMBG, with an A1C every 3 months, SMBG with the patients told to contact their physician for advice on using the results, and a third group that received training on the use of SMBG to monitor physical activity, food, and effects of medications (note how this last group parallels most educators and physicians current approach).  Starting A1Cs averaged 7.5, and though there was a trend toward better A1Cs in the SMBG groups, it was small and not significant at the one-year follow-up.  Only 30% of patients had their glucose-lowering medications increased during the study, and again, there was no difference between the three groups.

I think that the main lesson learned in this study is that A1Cs didn’t improve, yet only a minority of patients had their treatment advanced.  The additional information provided by a glucose meter doesn’t help if it isn’t utilized to implement changes in either lifestyle or medication.

The ESMON study followed 184 patients with newly diagnosed Type2 diabetes for one year, with everyone receiving baseline diabetes education.  One group was randomized to using SMBG and the other group to none.  Patients in the SMBG group were given advice on how to use their results to interpret the effects of activity and food, and at regular clinic visits their meters were downloaded and the results reviewed with the physician and educators.  As opposed to the DiGEM study, the patients in this SMBG showed a significant improvement in their average A1C, from 8.8% at the beginning of the study to 6.9% at the one-year follow-up.  However, the group with no SMBG showed a similar improvement, from 8.6% at baseline to 6.9% at follow-up, with no significant difference between the SMBG and no SMBG groups.  Why?  Because both groups were treated with an aggressive regimen, with protocol-driven increases in their medications if their A1C was above 7.5%.

To me, the main lesson from this study was not about SMBG per se.  Rather, it showed us that advancing treatment when the A1C is above target produces excellent results.  This point seems simple, but we know that many patients with diabetes do not have their treatment changed when they don’t meet their A1C goal.

The third lesson from these two thorough studies stems from the finding that patients who used SMBG were slightly but significantly more likely to report symptoms of anxiety and depression.  These feelings didn’t occur in every patient, obviously, but the increase is worrisome.  The educators and physicians involved in these studies were well-trained, experienced, and committed to helping their patients with diabetes.  Yet somehow many patients ended up feeling bad about their SMBG results.  The lesson here was that even when care providers mean well, SMBG can produce negative feelings.  Combined with the lack of improvement in A1C and the cost of SMBG, it is easy to see why some observers conclude that SMBG should not be routinely used in patients not on insulin.

I have some different conclusions. First, completely aside from using glucose meters: if we don’t change treatment, lifestyle and/or medications when the A1C is high, nothing good will happen (DiGEM).  And when we do change treatments (ESMON), something good will often happen, whether we use SMBG or not.  Another conclusion is that SMBG can produce negative feelings in people.  We need to realize and emphasize that blood glucose results themselves are never bad, but only supply information.  Your A1C is an accurate and clinically important judge of your overall glucose control, but is not a judgment of your self-worth.  Physicians, educators and the ADA provide daily blood glucose targets that are useful, but are simply not obtainable all of the time for most people with diabetes.  We also provide A1C goals, which are both more important and more obtainable.  As an analogy, daily blood glucose goals are like my having a personal goal of making everyone I meet feel happy, and contributing to world peace.  Goals to aspire to, but ones that I know I won’t meet – even if I were Miss America, which I am not.  The A1C goal is more important and more realistic, like my having a goal of helping my patients, supporting my family, and being a productive member of my community.  Not that easy, but doable.

So what should you do if you have Type2 diabetes and are not on insulin?   By all means check your glucose, and let this inform you about the effects of food, activity, and medication.  Try using the glucose average function on your meter.  Almost every meter can display the average of your last 7, 14, or 30 days of glucose results, and tell you if you are trending up or down.  Most importantly, if your A1C is above target, use your SMBG results to look for solutions; Is there a time of day when you are always higher? Are weekdays worse than weekends?  What happens after meals?   Take this information to your health care provider, so that together you can decide on some CHANGE that will move your A1C back toward target.  Life changes, and your diabetes changes.  If you don’t change your diabetes treatment, you will be left behind.  Using your SMBG results to stay on goal will ensure that you will stay ahead of your diabetes.

Thanks for the down-to-Earth analysis once again, Rich. Much appreciated!