Diabetes and Heart Disease Study Halted

The government abruptly halted aggressive treatment in a major study of diabetes and heart disease after a surprising number of deaths among patients who pushed their blood sugar to super-lows - findings that call into question a growing movement in diabetes care.

Wednesday's move doesn't affect health guidelines for most Type 2 diabetics, but it raises concern about a particularly vulnerable group: Patients at especially high risk of heart attack or stroke.

The 10,000-patient study, dubbed ACCORD, was supposed to answer a big question: Could pushing blood sugar to near-normal levels, below today's recommended target, help protect these high-risk patients' hearts?

Instead, the National Institutes of Health took the rare step of halting part of the study 18 months early - citing 257 deaths among aggressively treated patients compared to 203 among diabetics given more standard care.

That translates into an extra three deaths for every 1,000 participants per year, and researchers were at a loss to explain why. Diabetics' blood sugar wasn't too low, a condition known as hypoglycemia. And a close look at the multiple medications patients used, including the drug Avandia that is suspected of being heart-risky, showed no sign that any were to blame.

Ironically, the study's death rate was well below what doctors usually see in Type 2 diabetics, probably due to the extra care and monitoring they received as part of the research.

Moreover, the aggressively treated patients suffered about 10 percent fewer heart attacks overall than their counterparts, said Dr. William Friedewald of Columbia University, who helped monitor the study.

"However, it appeared that if a heart attack did occur, it was more likely to be fatal" in that group, Friedewald said. "In addition, the intensive treatment group had more unexpected sudden deaths, even without a clear heart attack."

So for now, the NIH's message: Diabetics with heart disease shouldn't strive for near-normal glucose, but to a level long described as optimal for all diabetics - around 7 on a measurement scale known as the A1C.

Some 21 million Americans have diabetes, meaning their bodies can't properly regulate blood sugar, or glucose. Diabetics already are at increased risk of heart disease. Type 2 diabetes, the most common form, is linked to obesity, which in turn harms the heart. Plus, high blood sugar over time damages blood vessels.

The A1C test tracks average glucose levels over two or three months. People without diabetes have A1C levels as low as 5.

The American Diabetes Association has long recommended that diabetics aim to get their A1C level below 7, far below the long-common 8 or 9. Every point-drop lowers the risk of serious complications, such as blindness or kidney failure, by 25 percent to 40 percent.