Researchers at St. Louis's Washington University have found that liposuction does not lessen heart disease and diabetes risk factors such as blood pressure, cholesterol or insulin levels, reports CBS News Correspondent Barry Bagnato.
In the study, obese women who dropped up to 23 pounds of belly fat by way of liposuction did not appear to lower their risk of diabetes or heart disease, both of which are fat-related.
It is a frustrating and surprising finding to researchers who believed that surgically removing fat would help restore a healthier body chemistry.
"It's not how much fat you remove, but how you remove the fat that is really what is more important," said lead study author Dr. Samuel Klein, at Washington University in St. Louis. "We have to go back to the same old traditional recommendation of lose weight and be more physically active."
Liposuction is the nation's most popular form of cosmetic surgery. About 400,000 fat-sucking liposuction procedures are done every year in this country.
The latest study, published in Thursday's New England Journal of Medicine, involved 15 obese women who underwent cosmetic liposuction.
The women's blood chemistry and pressure — which reflect the risk of diabetes and heart disease — were checked before surgery and about three months after. While the women were slimmer afterward, their medical profiles were almost identical.
Body fat has been increasingly tied to diabetes, heart disease, cancer and other diseases in recent years. It turns out that fat doesn't just make the heart pump harder; fat cells churn out a brew of metabolic products that can harm health.
The notion that surgically removing fat should help restore a healthier chemistry to the body still cannot be completely discarded. For one thing, this study involved a small number of people — and all of them women.
Also, Barbara Corkey, a Boston Medical Center biochemist who is president of the North American Association for the Study of Obesity, said the liposuction may have left too much body fat behind or siphoned away the wrong kind of fat.
The surgery removed only belly fat, leaving untouched a deeper layer of what is known as visceral fat. The deeper fat may prove to be more dangerous. It feeds metabolic products more directly into the pancreas, which manufactures the hormone insulin. It is insulin production or metabolism that goes haywire in diabetics.
Visceral fat is harder, but not impossible, to trim by surgery.
Ultimately, doctors may find that fat cells need to shrink in size, and not just number, to restore a healthier chemical balance. Dieting does make fat cells smaller.
It may also be that the body needs to run an energy deficit regimen — through dieting and exercise — to switch on healthier fat chemistry.
The liposuction research suggests that "even if one could suddenly remove the fat tissue per se, you really haven't changed the underlying process," said Dr. David Kelley, who runs the Obesity and Nutrition Research Center at the University of Pittsburgh Medical Center.