Deaths partially halt diabetes study
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
"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.
"We obviously were surprised. We
were hoping for a positive outcome, but the reason we do this research is we
don't know that," said study researcher Dr. Hertzel Gerstein of
The findings contradict previous
research suggesting that the lower diabetics can make their blood sugar, the
better. That had specialists cautioning Wednesday that it's too soon to know if
the finding among heart patients was a fluke, or a real sign of how exquisitely
tailored to each patient's risk factors diabetes care must be.
"Everything else has suggested,
for 50 years or more, that tight control was good," said Dr. James Dove,
president of the
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.
Recent research shows that about half
of
Getting too far below an A1C of 7 is
very difficult, and very few patients outside of research studies succeed. The
NIH study aimed to have aggressively treated patients dip below a level of 6,
into near-normal range. Only half got below 6.4, compared to an A1C of 7.5
among study volunteers getting standard treatment.
Wednesday's announcement does not
change that guideline. Rather, the NIH's National Heart, Lung and Blood
Institute added the nuance that diabetics with heart disease stop at a level of
7 rather than dip below, while researchers try to figure out what happened.
They have switched all the study participants to standard therapy, and will
track their health until June 2009.