Is SMBG for Type 2 Useful?

Dana Brackney PhD, RN, CNS, CDE, BC-ADM

This is a report of a presentation at AADE 2015 by Dana Brackney PhD, RN, CNS, CDE, BC-ADM entitled "Use of SMBG in T2 DM Self-Management:‘Knowing Where I Am At.’"  There still remains a huge controversy on whether Self-Monitored Blood Glucose (SMBG) is effective and worth the cost in diabetes patients who are not insulin using.  This presentation was a breath of fresh air as it described purposeful SMGB and efforts to measure positive outcomes.  While this is a small and limited study, hopefully this will start to gather more interest in doing studies where SMBG is done in a way that is patient centered and purposeful.  There are many patients that learn to "Eat to Your Meter" with great success.  It is really too bad that studies of SMBG effectiveness have been so deeply flawed and although they claim to be "intervention" studies, if you don't use SMBG in a purposeful way then you don't really have an intervention.

There is a long-history of studies looking at SMBG in non-insulin using diabetes patients with many studies showing that testing isn't useful.  A recent Cochrane meta analysis even concluded that "The evidence for potentially beneficial SMBG-induced effects on glycemic control, hypoglycemic periods, and potential harms in type 2 diabetic patients who are not treated with insulin does not justify the use of SMBG."  How could this possibly be?  This is a serious question since these studies are being used by Medicare and NHS to deny test supplies to diabetes patients.

Most alarming when you dig into these studies is that these studies are all fundamentally flawed.  They are based on a premise that test results are not actionable by the patient and are primarily for use by the medical team.  When I was first diagnosed I was given test strips and told to log all my results and report them back to my healthcare team.  But my healthcare team didn't even look at the results, they had no time.  All they cared about was my A1c.  So it is absolutely no surprise that SMBG doesn't matter in that context.

I was pleased to attend a presentation by Dr. Brackney on August 5th at AADE 2015 where she reported on a small study looking at the meaning of SMBG for patients and how the role of SMBG is perceived by patients.  The presentation was in fact a summary of the original research work that Dr. Brackney performed for her PhD dissertation.  The summary that Dr. Brackney presented highlighted that SMBG provided different meaning and functions thus did not serve any one purpose.  This makes intuitive sense as SMBG clearly has a different function for someone newly diagnosed, someone seeking behavior change and a veteran who keeping up a routine to maintain their health.  Each of these time phases has different meaning and functions for SMBG, with someone newly diagnosed looking to SMBG for confirmation and comfort.  Someone looking to change behavior will use SMBG to help make informed changes to improve their blood sugar control.  And someone who is maintaining may simply want to routinely monitor their condition to see that they are still on track.

Dr. Brackney study recruited 11 non-insulin using patients that were recently diagnosed.  They were given instruction based on a self-regulating SMBG guide on how to purposefully perform SMBG and the timings and frequencies to support those SMBG purposes.  The results of this group are shown below:

All the patients achieved a goal of getting their A1c to below 7% over a period of two years even though some started with an A1c as high as 9.6%.  Most importantly was that SMBG actually taught patients to understand their diabetes.  Most patients did not understand that their fasting blood sugars would be elevated (particularly in the morning) and that it had nothing to do with what they ate.  And being able to make the connection between dietary and exercise behavior and blood sugar turns out to be vital to having patients understand how behavior change can affect things.  And it was also clear that getting patients to develop a proper long-term healthy non-judgmental relationship with SMBG results as just being numbers is really hard.

In Dr. Brackney's work I found an interesting set of behaviors from McAndrew (2007) which succinctly characterized things that are necessary for SMBG to be properly implemented:

1. Know how to take a reading.
2. Understand when the reading is above or below target values.
3. See the connection between deviant readings and prior behavior.
4. Have and implement an action plan to control glucose levels.
5. Rely more heavily on SMBG readings and give less weight to subjective feelings of well-being and possibly false signs of hypoglycemic distress.
6. Create simple action plans that will allow the patient to integrate them into his or her ongoing life patterns, the use of SMBG, and the behaviors needed for effective blood glucose management.
7. Evaluate glucose reading in a nonjudgmental framework.

It is interesting that the vast majority of studies that have been previously performed looking at SMBG effectiveness have failed to embrace these behaviors.  In particular, when you fail to teach patients the connection between readings and how to take action based on those readings then SMBG simply becomes ineffective.  Above all I would expect that the diabetes educator community would embrace this concept deeply but I think they have been deeply conflicted about how dietary action plans should be taught.  For many patients, developing an action plan to deal with high post postprandial readings becomes a situation of conflict between eating the recommend high carbohydrate diet and reducing carbohydrates in order to manage post postprandial blood sugars.  In practice, many patients learn on their own that restricting carbohydrates is a powerful action to take in response to deviant post postprandial numbers.  For many highly successful patients restricting carbohydrates and "Eating to Your Meter" has been a very successful strategy.  I would hope that this work might be followed up with a more extensive controlled intervention trial that included carbohydrate restriction as one of the primary action plans.  My bet is that those results would prove that all those previously flawed studies were wrong and that SMBG is vital and effective. And maybe in my ideal world of the future patients with non-insulin using type 2 diabetes would stop having their test strips withheld.