Self-monitoring of blood glucose (SMBG) has been around since 1975. Now, many people with diabetes check their glucose levels regularly. But some large studies question whether all those fingersticks really help. What do you think?
If you’re taking insulin, some self-monitoring is certainly advisable for safety reasons — to prevent lows, for example. But for people with Type 2 who are not on insulin, and even for some people with Type 1, I feel that the benefits of monitoring in the usual fashion are questionable.
I’ve observed over the years that most people check their blood glucose levels without thinking. They monitor at the same time or times every day, usually in the morning or before meals. Sometimes they record the numbers, or their meter does. Maybe they show the numbers to the doctor at appointments. He looks at them for a few seconds and then hands them back. If they’re too high, he might increase a dose or add a new medicine.
But he could have learned the same thing from a single A1C test, instead of 50 or 200 fingersticks. What do people really learn from monitoring without thinking about it?
Several studies have looked at whether SMBG is cost-effective. In a major study published in Diabetes Care, Mayer B. Davidson, MD, wrote, “In the US, a conservative estimate of the cost of SMBG is nearly $1.5 billion/year. This is a tremendous amount of money for an activity for which there is little…or no evidence for a beneficial outcome.”
Davidson went on to say that, “Simply measuring blood glucose is ineffective. In one study, increased frequency of SMBG resulted in lower A1C levels only in those who self-adjusted their insulin doses,” not in those who did not. So measuring is not enough. You have to do something about it.
Dutch doctors reviewed 12 major studies of SMBG in Type 2 diabetes and found that A1C did come down an average of 0.3% after monitoring started, for about six months. But by 12 months, the numbers had returned to baseline levels, suggesting that people did not stay with whatever lifestyle changes they had started in response to SMBG.
How could knowing your glucose numbers not help glucose control? Davidson gives three possible reasons. People receive little or no feedback on their results from professionals. Most people are not taught the self-management skills required to lower the measured glucose values.
Finally, and most important from my perspective, is that “the vast majority of patients measure their glucose level either fasting or [before meals,] rather than post-prandially [after meals.] Fasting values serve neither to educate (there is no information on the effect of meal composition or size) nor to effectively motivate.”
Additionally, the Dutch review found that SMBG had no effect on people’s diabetes satisfaction, general well-being, or health-related quality of life. This doesn’t surprise me, as fingerstick monitoring can be unpleasant.
William Polonsky, PhD, CDE, says that people with diabetes may see SMBG as “burdensome and pointless.” In my view, that is an accurate appraisal of routine monitoring. However, Polonsky says there is a better way. His team has published several papers on the “Structured Testing Program” or STeP, a trial that evaluated the effectiveness of structured blood glucose monitoring.
With structured blood glucose monitoring, people were taught to write down events that could impact their blood glucose control, such as exercise and changes in diet, along with blood glucose results from seven significant points — two hours after eating and at bedtime, for example — during the day. They were then taught, along with their health-care providers, how to interpret and identify patterns in these results to best address any issues with their diabetes control.
Structured monitoring puts you in charge of your own care. Mindless monitoring is just another job on top of all the other work diabetes puts on you.
Polonsky’s studies have shown that people using structured monitoring gained much more confidence in their diabetes care, used fewer test strips, and had lower A1C levels as well. Confidence is good for you.
I need to know what you think about these issues, because I’m writing a booklet to help people monitor smarter. Please help me out. Do you monitor your blood glucose levels at all? If you do, do you have a plan, some specific questions you are trying to answer? What have you learned? How often do you monitor and when? What has been your overall experience with SMBG? Is it worth the trouble and expense? Thanks in advance for any advice you can give.