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| FILE - In this Sunday, April 29, 2012 file photo, a 19-year old diagnosed with diabetes gives herself an injection of insulin at her home in the Los Angeles suburb of Commerce, Calif. The "obesity paradox" — the controversial notion that being overweight might actually be healthier for some people with diabetes — seems to be a myth, researchers report. A major study finds there's no survival advantage to being large, and a disadvantage to being very large. The study was published by the New England Journal of Medicine on Wednesday, Jan. 15, 2014. |
The "obesity paradox" -
the controversial notion that being overweight might actually be
healthier for some people with diabetes - seems to be a myth,
researchers report. A major study finds there's no survival advantage to
being large, and a disadvantage to being very large.
More
than 24 million Americans have diabetes, mostly Type 2, the kind that
is on the rise because of obesity. About two-thirds of U.S. adults are
overweight, including one-third who are obese.
Weighing
too much increases the chances of heart disease, cancer and premature
death. But some small studies have suggested this might not be true for
everyone, and that Type 2 diabetics might even benefit from a few extra
pounds - a "metabolic reserve" to help get them through sickness.
The
new research - which looked at deaths according to how much people
weighed when they were diagnosed with diabetes - dispels that idea.
"We
didn't see this protective effect at all," said one study leader,
Diedre Tobias of the Harvard School of Public Health. "The lowest risk
was seen in the normal-weight category."
The
National Institutes of Health and the American Diabetes Association paid
for the work. Results are in this week's New England Journal of
Medicine.
"It's a very convincing study" and
large enough to give a clear answer, said one independent expert, Dr.
Patrick Remington, associate dean for public health at the University of
Wisconsin-Madison.
It involved 11,427 female
nurses and male health professionals diagnosed with diabetes sometime
after enrolling in two long-running health studies. They were grouped
according to body mass index, a measure of height and weight. People
with a BMI over 25 are considered overweight, and 30 or higher, obese. A
5-foot-8-inch person would be overweight at 164 pounds and obese at
197.
During more than 15 years of follow-up,
there were 3,083 deaths. The lowest risk was among those in the normal
range - BMIs of 22.5 to 25.
For the rest,
researchers saw a J-shaped curve - deaths trended higher at both
extremes. Being just a little overweight did not substantially raise the
risk of death, but the trend was in that direction.
The
study was big enough that researchers could look at subgroups. For
those under 65 when they were diagnosed with diabetes, the risk of death
rose directly in relation to BMI. The same was true of people who had
never smoked.
Trends for smokers and people
over 65 were less uniform. Smokers had higher death rates in general.
Smoking suppresses appetite and contributes to lower weight, but
contributes so strongly to many diseases that it can overshadow and
complicate efforts to measure the effect of weight alone, Tobias said.
Older people have many other health conditions that also make it hard to
see the effect of BMI.
The results support
guidelines urging people to keep a healthy weight, said Dr. Donna Ryan
of Louisiana State University's Pennington Biomedical Research Center.
Even though being modestly overweight did not raise the risk of dying
very much in this study, many others show that it impairs quality of
life by contributing to high blood pressure, high cholesterol and other
problems, she said.
Ryan said she doubted that overweight people would think it's OK to be a little pudgy.
"Are you kidding?" she said. "Everybody is trying to lose weight."
