Is Self-Monitoring Your Blood Sugar Really Worthwhile?
When a type 2 diabetic asked me years ago how often he should self-monitor blood glucose (SMBG), I began to ponder the true value of this procedure. I recalled that before the home test was available by which you could take a drop of blood from your fingertip and use it to assess your blood glucose level, people used to test their urine. But then it was discovered that the kidney would release glucose through the urine only when one’s blood sugar level reached 180 mg/dl, and diabetes specialists decided that this was not a very accurate way to measure blood glucose since it was already too high. That was one impetus for inventing the handheld blood monitoring device and test strips that are commonly used today.
I began asking diabetic patients how often they checked blood sugar levels. Oddly, the answers ranged all over the place. Some people tested in the morning only while others did morning and evening. Some tested before and after meals. Some tested only if they wanted to find out their blood sugar level after a meal or workout, or to see whether low blood sugar was the reason for how they were feeling at that time. Some tested only fasting blood sugar, while others tested fasting and then again two hours after meals. Some were allowed to adjust their diabetic medication based on the test result. Some, who did not take diabetic medication daily, took medication only if their level was above normal.
When I asked doctors about the value of SMBG, the answers were equally surprising. Most never discussed the topic with their diabetic patients, nor asked them for their results. Most of the doctors I talked to used not the results from self-monitoring of blood glucose but the laboratory test called the A1C to guide treatment decisions. And yet, most doctors encouraged their patients to test their blood sugar at home with the reasoning that this could make patients aware of their condition and therefore more compliant with medications. It effectively gives patients more self-care responsibilities and motivates them toward healthier lifestyle behaviors. I found it strange, however, that absent in my survey of doctors and patients was any mention that SMBG could help reduce the incidence of diabetic complications.
The cost of SMBG in the United States has been estimated at $500 million per year in the purchasing of monitors and test strips. There is some evidence suggesting a statistically significant but clinically modest reduction in the A1C of those who perform SMBG compared to those who do not. However, there are no controlled studies showing that regular SMBG actually reduces the incidence of complications of Type 2 diabetes.
Some diabetes practitioners have sought to explain this lack of beneficial results as being due to patients not being adequately educated to interpret their results, or not willing to make the lifestyle or treatment modifications required to reverse their diabetes. But if this is so, I must ask, why bother encouraging patients to perform SMBG? Or, why not educate them better or help them more assertively to make the lifestyle changes that could impact their diabetes, regardless of SMBG?
When I checked on some other chronic medical conditions for which self-monitoring tests are available, I found a tremendous inconsistency in the medical profession. A person with high blood pressure is not asked to check blood pressure multiple times daily on a routine basis, in spite of the fact high blood pressure could lead to stroke, and low blood pressure could cause fainting episodes. A person with asthma is not asked to check his or her speed of airflow multiple times a day, although a simple devise called Peak Flow Meter can measure it easily.
Ultimately, my conclusion is that SMBG is simply a footnote in your diabetes care at best, if not a medically useless procedure with regards to reduction in diabetic complications. It appears to have little significant impact in helping people change their attitude towards self-care, nor to change their eating habits. For some people, learning that they have high blood sugar in spite of being careful might even compound their sense of control and make them depressed.
If you are self-monitoring, or told to do so, my recommendation is to ask your diabetes care provider what can you expect from SMBG in terms of reducing the chances of your having future complications from your type 2 diabetes. If your medical provider insists on the obvious, i.e., that the consequences are up to you, then I suggest that what is most important for you is to make more of a commitment to changing your lifestyle to live a diabetes-free life rather than spending time for self-monitoring and worrying about the results.
What does changing your lifestyle mean? First, ask yourself, which is better: taking medications to drive glucose out of the blood (while not knowing exactly where it goes) or not even putting glucose into the body in the first place? Then, take time to read my prior blogs about my theory about the cause of Type 2 diabetes—the overconsumption of grains and grain-flour products that triggers a normal body metabolism to go haywire. Just reducing or eliminating your consumption of breads, muffins, doughnuts, cakes, cookies, and also rice and corn products, will help you avoid or reverse diabetes far better than testing your blood sugar to see the effect of medications that are designed to lower it.