TUESDAY, Jan. 3 (HealthDay News) -- Obese people who undergo
weight loss surgery appear to reduce their risk of heart attack,
stroke and death, Swedish researchers report.
And these heart-health benefits seem to be connected with
metabolic changes that occur after the surgery, such as altered
insulin production, rather than the weight loss, the researchers
"Bariatric surgery is associated with about 30 percent reduction both in the incidence of heart attack and stroke," said lead researcher Dr. Lars Sjostrom, a professor at the University of Gothenburg's Institute of Medicine.
"Body mass index before the operation does not predict the surgical treatment effect, while insulin concentration before surgery is strongly related to future benefit," he said.
Bariatric surgery involves altering the stomach in order to
reduce the amount of food consumed or digested. Given these new
findings, some experts think the criteria for the operations should
include more than body mass index (BMI), a measurement that takes
into account height and weight.
"Before, we thought surgery was a shortcut for patients who didn't have the willpower to lose weight on their own," said Dr. Francesco Rubino, chief of gastrointestinal metabolic surgery at Weill Cornell Medical College in New York City. However, for patients with uncontrolled diabetes or heart disease, surgery might be life-saving, he said.
"I don't think a BMI cutoff should disqualify patients," Rubino said. A BMI of 30 or more is considered obese.
The study, started in 1987 and reported in the Jan. 4 issue of
Journal of the American Medical Association, is the first prospective study to show these cardiovascular benefits from weight loss surgery, the researchers said.
Sjostrom's team, using the Swedish Obese Subjects study, looked
at data on more than 2,000 study participants who underwent
bariatric surgery and more than 2,000 who didn't. All were
middle-aged, white and obese, with and without pre-existing health
The types of bariatric surgery included gastric bypass, in which
stomach size is reduced with staples; banding, which uses an
adjustable band to restrict food intake; and vertical banded
gastroplasty, which also limits food intake.
During more than 14 years of follow-up, 28 people who had
bariatric surgery died from a cardiovascular problem, compared with
49 who didn't have surgery, the researchers found.
There were 199 first-time heart attacks or strokes among the
surgical patients, compared with 234 among the non-surgery
participants, they noted.
Fewer fatal heart attacks occurred in the surgery group than the
non-surgery group (22 versus 37). Surgery was also associated with
fewer fatal and non-fatal strokes.
But no significant relationship was seen between weight loss and
cardiovascular events in either group, the investigators found.
While that finding could be a statistical fluke, Sjostrom said
other reasons could explain the finding.
"No non-surgical treatment has shown significant favorable effects on cardiovascular events in the obese," Sjostrom said.
"Our findings stress even more the favorable effects of bariatric surgery as compared to usual care. Also, all guidelines for bariatric surgery probably have to be modified since they all use BMI as the main criterion for patient selection," he said.
Dr. Edward Livingston, author of an accompanying journal
editorial, agreed that weight should no longer be the determining
factor for bariatric surgery.
Based on these findings, "the surgery should be targeted at
treating a condition that will improve with weight loss," said
Livingston, the Dr. Lee Hudson-Robert R. Penn Chair in Surgery
chair of surgery at the University of Texas Southwestern Medical
Center at Dallas. "There is something these patients benefit from
from surgery that's not weight loss."
Obese patients who have diabetes or sleep apnea might fit this
category, as well as people with knee or hip arthritis who need a
joint replacement, Livingston said.
Why these conditions improve isn't clear, he noted. It could be
the operation, or better medical care, or patients taking better
care of themselves, he suggested.
Depending on the actual operation, bariatric surgery costs
between $10,000 and $20,000 plus follow-up costs, and insurance
coverage is very inconsistent, Livingston added.
"I would approach bariatric surgery cautiously. It's not a panacea. It has a lot of downsides," Livingston explained. Complications can include leaks, infections and embolism (a sudden blockage in an artery), he pointed out.
Also, many patients gain back the weight lost after the surgery.
"We really don't know the very long-term results of these
operations," Livingston said.
For more information on bariatric surgery, visit the
U.S. National Library of Medicine.