Is My Blood Glucose Control "Too Good"?
A few months ago, I was advised by a diabetes specialist that my blood glucose control was "too good." My A1C has been between 5 and 5.5 percent for the past five years. My specialist said I should be somewhere between 6.5 and 7 percent. How does this match up with ADA recommendations? Marvin Britton, Wabasha, Minnesota
Sue Kirkman, MD, responds:
The American Diabetes Association recommends an A1C target of less than 7 percent for most adults with diabetes, but also advises that treatment goals should be individualized. There is a lot of evidence that good glucose control helps prevent or delay the small-vessel complications of diabetes, such as kidney or eye disease. However, glucose control may not have much impact once complications are advanced, such as when someone is blind from retinopathy. Also, a person with a life expectancy of only a few years (because of advanced cancer, for example) is unlikely to benefit much from tight control, so the A1C target could be relaxed in that case.
Whether good glucose control helps prevent heart attacks or strokes is a more difficult question. Several large studies suggest that it might not, although others propose that if a person practices good glucose control starting soon after diagnosis, it may reduce the rate of heart attacks and of deaths from heart disease. One of the large studies of type 2 diabetes and cardiovascular complications, the ACCORD trial, compared intensive glucose control (a target A1C under 6 percent) to standard glucose control (a target A1C between 7 and 8 percent) in people with diabetes. Surprisingly, the mortality rate was highest in the intensive group. Several other large studies of type 2 diabetes have not shown this, so it has been difficult to determine what accounted for the ACCORD results.
Another factor that may affect how tightly you control your blood glucose is your risk for hypoglycemia (low blood glucose). People who take insulin or certain oral medications, like glyburide, are at the highest risk. If your low A1C can be partially attributed to episodes of hypoglycemia, then your physician would most likely advise you to relax your glucose control targets.
Your A1C level has been in the normal range and stable for years. Whether your A1C needs to be "raised" really depends on how you are doing overall, and may be affected by things like hypoglycemia, complications you're experiencing, or other medical conditions. You may have really good glucose control due to a healthy diet and exercise regimen, in which case there seems to be no reason for concern. You and the diabetes specialist who made this recommendation should talk more about what targets make sense for you.