2 Diabetes Studies Give Mixed Message
Intense Blood Sugar Control Cuts Eye and Kidney Complications, but Not Heart Complications
Study Details: ACCORD
In the ACCORD trial (Action to Control Cardiovascular Risk in Diabetes), researchers followed more than 10,000 participants with type 2 diabetes, focusing on whether intense control of blood glucose could reduce the risk of cardiovascular disease.
The target A1c in the intervention group was less than 6% and 7% to 7.9% in the standard group.
When it was found that the intense treatment group had a 22% higher relative risk of death than the standard treatment group, the intense treatment arm was terminated.
The increased death rate remains a puzzle, says Hertzel Gerstein, MD, a principal investigator of the ACCORD study. Since the arm was terminated, he says, many analyses have been done. "At this point in time, none of these analyses have identified any one reason why this occurred," he says.
ACCORD patients were at high risk, the researchers note: 35% had had a stroke or heart attack before entering the trial, and the rest had risk factors such as high blood pressure.
The new study results from ADVANCE suggest that many of those with type 2 diabetes shouldn't worry about the previous result showing an increased risk of cardiovascular death with intense control, says Spyros Mezitis, MD, an endocrinologist at Lenox Hill Hospital and assistant professor of clinical medicine, New York Presbyterian-Cornell Medical Center, New York. "We shouldn't be much worried about the ACCORD results," he says.
He reviewed the ADVANCE study for WebMD but was not involved in it.
"The major result shown in this study is the 21% reduction in risk for kidney disease," he says. "That was major." Also major, he adds: "No evidence of increased risk of death in the intensive control group."
The ACCORD and ADVANCE studies were made up of different participants, he points out. "It is a different study," he says of the ACCORD study. Blood sugars were worse initially for patients in that study. "You are comparing apples and oranges."
Many unanswered questions remain, experts who reviewed the study for WebMD concur. ''The question that will probably not be answered by the data we have from the ACCORD trial is whether the problem is with the goal itself of an A1c of 6.4% or ... how you use the insulin to achieve that goal?" says Andrew Drexler, MD, director of the Gonda Diabetes Center at the University of California Los Angeles.
"Some patients appear to be only on long-acting insulin, others on short- and long-acting," Drexler says. "Which of those two strategies were used could potentially explain the difference in outcome, but that data does not appear to exist."
"Early and aggressive blood glucose control remains the optimum treatment approach for people with type 2 diabetes," says James Underberg, MD, clinical assistant professor of medicine at New York University Medical School, who also reviewed study results for WebMD. The ACCORD trial, he says, "was conducted in a select patient population, which is just not reflective of the majority of the millions of Americans with type 2 diabetes."