After seeing an increase in deaths among type 2 participants, the National Heart Lung and Blood Institute (NHLBI) has halted the intense blood sugar control portion of its years-long study on controlling cardiovascular risks to people with diabetes.
Over a seven-year period, ACCORD (Action to Control Cardiovascular Risk in Diabetes) has tracked 10,251 people with diabetes (ages 40 to 84 at 77 U.S. and Canadian sites) who have heart disease, obesity or high blood pressure – factors that put them at increased risk of heart attacks or strokes.
A panel monitoring results of the study found that 257 patients undergoing intensive treatment had died over its course, versus 203 deaths among those receiving standard treatment. The difference of 54 deaths was 3 per 1,000 participants. Not only was that figure statistically significant, half of the deaths in the intensive-control group were from heart disease – which intensive control had been designed to avoid.
The agency is contacting type 2 patients who participated in the intense-control sector of the study to inform them that it has been suspended, and to recommend that they begin adhering to less stringent goals.
In one section of the ACCORD study, the NHLBI split participants into two groups. One group received intensive blood glucose control treatment designed to bring its members’ average A1c down to 6%. The goal was reach A1c’s that were as close as possible to those found in people without diabetes. Medications given to the intensive-control group included Avandia, Actos, Byetta, Precose and generic drugs. These were combined with dietary and exercise guidelines designed to drive down A1c’s.
The other group was given less intensive therapy designed to help it achieve average A1c’s from 7% to 7.9%. While not considered ideal, that range of A1c’s is the average among people with diabetes.
Despite the concentrated effort that included daily testing, drugs and close monitoring by doctors, only half of the members of the intensive control group were able to achieve A1c’s of 6.4% or less.
The increase in deaths calls into question a long-held assumption among researchers that lower blood sugar levels decrease the health risks of people with diabetes, especially through the reduction of vascular inflammation caused by high blood glucose.
Editor’s Note: We will continue to track this story as researchers seek the causes of the unexpected increase in heart disease and mortality.