WASHINGTON - Aggressively reducing blood sugar levels as low as possible in high-risk diabetes patients appears to increase the chance of dying from a heart attack or stroke, according to major government study that stunned specialists.
The discovery, announced yesterday, prompted federal health officials to immediately halt one part of the massive trial so that thousands of the type 2 diabetes patients in the study could be notified and switched to less-intensive, less-risky treatment.
"As always, our primary concern is to protect the safety of our study volunteers," said Dr. Elizabeth G. Nabel, director of the National Heart, Lung and Blood Institute, which is sponsoring the study.
Although the reason for the increased risk of death is unknown, Nabel and other experts stressed that the benefits of blood sugar control have been well established for diabetics, and patients should not make any changes in their care without consulting their doctors.
But the findings cast doubt on a major assumption about diabetes treatment - that pushing blood sugar levels as close to normal as possible would be better - and will force specialists to reassess their thinking about how to treat one of the nation's leading health problems.
"It's profoundly disappointing," said Richard Kahn, chief scientific and medical officer for the American Diabetes Association.
"This presents a real dilemma to patients and their physicians. How intensive should treatment be? We just don't know."
An estimated 21 million Americans suffer from type 2 diabetes, the most common form of the disease, and the number has been increasing because of the obesity epidemic.
Diabetes patients' blood sugar levels rise abnormally high, causing a host of serious complications, including nerve damage, amputations, blindness, and increased risk for heart attacks and strokes.
Many earlier studies had shown that tightly controlling blood sugar significantly reduced the risk for many complications.
The new study, known as the Action to Control Cardiovascular Risk in Diabetes, or ACCORD, trial was designed to convincingly test whether various aggressive treatment strategies reduce the risk for heart disease - the main cause of death among diabetics.
