Diabetes rating is compromise
Dear Dr. Roach: My father has Type 2 diabetes, and his primary care physician has said repeatedly that an A1C of 7.2 percent or 7.3 percent is nothing to worry about. He also says that the American Diabetes Association has told physicians to loosen their restrictions on diabetics. The wall chart in his office says that 7 percent is the max, and above that puts a person at risk for serious consequences. My father previously maintained an A1C of 5.5 percent to 6.2 percent. His A1C started going up after beginning a new blood pressure medicine.
His ophthalmologist was concerned about the 7.2 percent A1C. His report says, “serious diabetes that is not managed properly — strongly recommend getting a second opinion.” What do you think? — G.M.
Answer: I can see why you might be upset. You are getting mixed messages. Let’s go over the study that has changed the A1C (measure of blood sugar control) goal for most older adults with Type 2 diabetes.
The blood-sugar-control arm of the ACCORD trial was designed to test whether “tight” control of diabetes would be superior to “standard” control. Half of the group had an A1C goal of less than 6 percent, and the others had a goal of 7 percent to 7.9 percent. In what was a surprise to the investigators, the study was halted in 2008 by the data safety monitoring board when there were an excessive number of deaths in the “less than 6 percent group” (about 22 percent higher, mostly from heart attack and stroke, termed “macrovascular,” since they involve large blood vessels).
However, many other trials have shown that the rates of microvascular complications, especially diabetic eye disease (retinopathy) and kidney disease, are lower in people with lower A1C levels. This is why the ophthalmologist was concerned about your father’s A1C being above 7 percent.
Every A1C point above 7 increases microvascular complication rates by about 35 percent.
Although other trials have not shown the increased heart attack and stroke risk from lower A1C levels, the standard of care now among most experts in diabetes is to aim for an A1C around 7 percent in older adults at higher risk for cardiovascular disease. The results of the ACCORD trial are not appropriately applied to younger people, newly diagnosed with diabetes.
In your father’s case, the doctor needs to balance out the goal of “not too low for macrovascular disease” against “as low as practical to reduce microvascular disease.” Even if I might aim a little lower, 7.2 percent is a reasonable compromise.