A paper denigrating the value of patient self monitoring of blood glucose (SMBG) was published in the British Medical Journal a few days ago. Once again I am mystified that highly qualified medical researchers can spend tens of thousands of dollars (or, in this case, Pounds) to come up with a worthless result.
BMJ, doi:10.1136/bmj.39247.447431.BE (published 25 June 2007)
research-article
Impact of self monitoring of blood glucose in the management of patients with non-insulin treated diabetes: open parallel group randomised trial
Read the full paper here: http://www.bmj.com/cgi/content/full/bmj.39247.447431.BEv1
Their conclusions:
Conclusions
Evidence is not convincing of an effect of self monitoring blood glucose, with or without instruction in incorporating findings into self care, in improving glycaemic control compared with usual care in reasonably well controlled non-insulin treated patients with type 2 diabetes.
How did they arrive at that conclusion? In my opinion they failed to understand how to use SMBG systematically and had no concept at all of the process of using test results as feedback to change input for better results.
Rather than say it all twice, I'll repeat below my post to the BMJ "rapid response" section after the article. Hopefully, they will publish it; if not, at least it will appear here:
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Response to BMJ
I am not a doctor. I am a type 2 diabetic patient who has a keen interest in patient self-management of diabetes, and who has spent far too much time over the past four years discussing this with other diabetics around the world on the net and personally. My only relevant publication is a patient's view online at http://loraldiabetes.blogspot.com/
This is not the first poorly performed study of blood glucose testing techniques published in the past twelve months, including one in my own country. All have suffered from the same basic flaw. SMBG is pointless – as is any testing of any sort – if the results are not used to either confirm that things are as expected or to assess what changes need to be made to improve the results next time.
However, if SMBG is used systematically to assess the success of past treatments and to then make changes in those treatments, in a continuously iterative method, it can be spectacularly successful. I accept that BMJ readers will consider anything I say as anecdotal; however I have seen it happen hundreds of times over the past five years.
This study was a waste of time and effort because the patients in the "most intensive" group were given no training in evaluating their test results with a view to improvement. In fact the basic premises of their training doomed them to failure: "They were also 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." That was the worst thing they could have done - to maintain adherence to their present regimens, particularly diet. In fact they maintained it so well that they hardly changed their poor HbA1c levels at all.
As an aside, for the authors to consider A1c's in the mid 7's as "reasonably well controlled" is appalling to me. I would refer the authors to the EPIC Norfolk study which found that "HbA1c was continuously related to subsequent all cause, cardiovascular, and ischaemic heart disease mortality through the whole population distribution, with lowest rates in those with HbA1c concentrations below 5%. An increase of 1% in HbA1c was associated with a 28% (P<0.002) increase in risk of death " BMJ 2001;322:15 [Full] ( 6 January )
Now, back to SMBG. The single most important thing that the patient can do at home is modify diet. They should not change medications without doctor’s advice, there are realistic limits to the exercise they can add to their routine – but they can make dramatic changes in blood glucose levels with a diet modified by feed-back from post-prandial peak blood glucose levels.
I, and many of my friends around the world, have been following a systematic testing regimen that works for some years now. It is intensive in the initial stages, then becomes much more relaxed once individuals have created their own personal databases of foods and activities, so we know what foods and activities will cause blood glucose spikes (at the peak, not necessarily at two hours), and which won’t. It’s as simple as that.
I challenge the authors of this paper – or any other researchers for that matter, to repeat the study but train the "most intensive" group as follows:
Eat, then test after eating at your peak spike time and if blood glucose levels are too high then review what you ate and change the menu next time. Then do that again, and again, and again until what you eat doesn’t spike you. You will get some surprises, particularly at breakfast time. The so-called "heart-healthy" breakfast is NOT for most type 2's. Similarly, you will find variations through the day - the same thing will have different effects at breakfast, lunch, dinner and supper
As you gradually improve your blood glucose levels, review the resulting way of eating to ensure adequate nutrition, fibre etc are included and adjust accordingly. Test, review, adjust until you have a flexible and interesting menu that is nutritious but does not "spike" your post-prandial blood glucose; a menu you can follow for the rest of your life.
Studies such as the one in question are meaningless if the SMBG is not performed systematically and with a defined purpose.
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Cheers, Alan