2 Diabetes Studies Give Mixed Message
Intense Blood Sugar Control Cuts Eye and Kidney Complications, but Not Heart Complications
Study Details: ADVANCE continued...
The average age of participants was 66, and about a third had already had a stroke or heart attack; the rest were at high risk for cardiovascular problems because of high cholesterol or other risk factors.
After five years, the intense group average A1c was 6.5% and the standard group, 7.3%, Patel says.
"The major effect shown in this is a 21% reduction in risk for kidney disease," Patel tells WebMD. "That was major."
While there was no significant reduction in heart attack, stroke, or death from cardiovascular disease with the intense group, they found "no evidence of increased risk of death [from cardiovascular disease] in the intensely controlled," Patel says.
"This is important because in the ACCORD study, they said those controlled at 6.5% had a significant increased risk of cardiovascular death and they don't know why," Patel says. That arm of the ACCORD study ended in February when the increased risk of death became apparent.
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.