New study affirms diabetes treatment
Contradicting unexpected findings released last week by American researchers, an Australian team Wednesday said it found no evidence that aggressive treatment of diabetes in patients with heart disease increased their risk of death.
Physicians and patients were shocked by last week’s announcement because it seemed to contradict a long-held tenet of diabetes treatment: that reducing blood glucose levels as much as possible improves health.
The new study, with nearly twice as much data as the American one and a longer follow-up time, provides some reassurance that the paradigm has not been overturned. But there are enough differences between the two studies to cloud the source of the discrepancy, experts said.
Doctors had already warned diabetics not to alter their treatment regimens, and the new findings from the George Institute for International Health in Sydney reinforced that.
“I think the message is ‘Don’t do anything until we get this sorted out,’ ” said Richard Kahn, chief scientific and medical officer of the American Diabetes Assn.
The American trial, known as ACCORD, focused on 10,251 patients in the U.S. and Canada with Type 2 diabetes who either had heart disease or were at high risk of developing it. About 65% of the 284,000 deaths linked to diabetes each year are caused by heart disease.
In the two arms of the trial, physicians used various combinations of lifestyle changes and drugs to reduce blood glucose levels -- as measured by concentrations of glycated hemoglobin, or A1C -- either to 6% or to between 7% and 7.5%. Healthy individuals have an A1C level of about 6%; normal treatment regimens achieve levels of 7% to 7.5%.
In a news conference Feb. 6, the ACCORD team said it was abandoning the intensive-treatment arm of the study because a preliminary analysis showed an excess of deaths in that group: 257, compared with 203 in the standard-treatment group.
In the light of that announcement, Dr. Stephen MacMahon of the George Institute asked the data monitoring and safety committee for his study, called ADVANCE, to look for excess deaths among its participants.
The ADVANCE study enrolled 11,140 high-risk patients in Europe, Asia, Australia and Canada and had treatment goals similar to that of the ACCORD trial.
“The interim results from ADVANCE provide no confirmation of the adverse mortality trend reported from the ACCORD study,” Dr. Rory Collins of the University of Oxford in England, chairman of the data monitoring committee, said in an e-mailed statement. He also noted that the interim results were based on twice as much data and similar levels of glucose control as the ACCORD study.
No other results from the study were released. A final report is expected later this year, along with results from a third trial that is also underway.
Experts were at a loss to explain the differences between the two studies. One possibility is that the Americans in the trial were heavier, and thus at higher risk of death from heart disease. The patients in the ADVANCE trial also received a drug that is not available in the United States.
Physicians said they hope that publication of all three reports will enable them to resolve the discrepancies.
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