Weight-loss surgery helps prevent diabetes: Swedish study | Reuters

Weight-loss surgery helps prevent diabetes: Swedish study | Reuters:

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Weight-loss surgery helps prevent diabetes: Swedish study

* Obese people who got surgery had lower risk over time

* More study needed, experts say

By Gene Emery

Aug 22 (Reuters Health) - Obese people who undergo weight-loss surgery can dramatically delay, and perhaps prevent, the onset of type 2 diabetes, Swedish researchers said on Wednesday.

Prior studies have shown that weight-loss surgery can reverse type 2 diabetes in patients who already have the condition. The latest findings offer evidence that the procedures can prevent the condition.

"We saw a marked delay (in the development of diabetes) over 15 years," said Dr. Lars Sjostrom of the University of Gothenburg in Sweden, whose study appears in the New England Journal of Medicine.

"Some of those surgical patients will probably develop diabetes later. But over a lifetime, there will be a large difference."

According to the World Health Organization, 346 million people worldwide have diabetes. Most of them, about 90 percent, have type 2 diabetes, the form of the disease linked with obesity and lack of exercise.

The link between obesity and diabetes is well-documented, and making lifestyle changes or taking weight-reducing drugs can cut the risk of diabetes by 40 to 45 percent.

The study, part of the larger Swedish Obese Subject study, was designed to see if the surgical weight loss would have the same effect. None of the patients included in the test had diabetes when the project began in 1987.

Participants chose whether or not to have surgery, and enrollment ended in February 2001. Stomach stapling was the most common procedure (69 percent), followed by gastric banding (19 percent) and gastric bypass (12 percent.)

When they compared the two groups over the course of the 15-year study, the team found that among the 1,658 volunteers who underwent weight-loss surgery, the annual risk of developing diabetes was about 1 in 150.

That compared with an annual risk of 1 in 35 among the 1,771 people in the control group, about four times higher than the treatment group.

The improvement was seen even though the people who underwent surgery initially were a bit heavier and had more risk factors than the control group at the start of the study.

"It's favorable in spite of these differences," Sjostrom said.

The improvements correlated with weight loss seen in the groups. In the surgery group, the average weight loss at the 15-year mark was 20 kilograms, or 44 pounds. The non-surgery group - which received standard care consisting of recommendations for healthier eating and more physical activity - stayed within three kilograms (7 pounds) of their starting weight.

Three patients died within 90 days of their surgery, and between 2 percent and 5 percent of patients had lung complications, vomiting, infections, bleeding or a blood clot.

According to the American Society for Metabolic and Bariatric Surgery, about 220,000 people had bariatric surgery in 2009. Surgery costs range from $11,500 to $26,000.

Dr. Danny Jacobs of Duke University School of Medicine in Durham, North Carolina, said in a commentary in the journal that "it remains impractical and unjustified to contemplate the performance of bariatric surgery in the millions of eligible obese adults."

Sjostrom said more studies are needed and a cost analysis of the pros and cons of surgery, now underway, could be published in a year or so.

SOURCE: bit.ly/PFZtyr New England Journal of Medicine, August 23, 2012. (Reporting by Gene Emery in Providence, Rhode Island; Editing by Ivan Oransky and Stacey Joyce)

HEALTHCARE

Obesity in Middle Age Tied to More Rapid Mental Decline: Study

Obesity in Middle Age Tied to More Rapid Mental Decline: Study

'Fat and fit' concept may not apply to brain function, research suggests

By Steven Reinberg
HealthDay Reporter

MONDAY, Aug. 20 (HealthDay News) -- People who are obese and suffer from high blood pressure and other problems linked to heart disease and diabetes may also see a faster decline in their mental abilities, according to a new study by French researchers.

Yet even obese people without these physical conditions experienced a faster decline in functions such as memory, the researchers noted. This finding belies the concept of being obese and healthy, they added.

"The prevalence of obesity is rising; 400 million adults were obese in 2005 and this number is expected to rise to over 700 million by 2015," said lead researcher Archana Singh-Manoux, research director of the Center for Research in Epidemiology & Population Health at INSERM, in Paris.

Obesity is known to be bad for health, she said. It is associated with a higher risk of early death and chronic illness.

"Our results add to this list of adverse health effects, showing poorer [mental] outcomes among the obese," Singh-Manoux said.

Having high blood pressure, high cholesterol or high blood sugar, or being on medication to control these conditions, are among the signs of metabolic syndrome. This cluster of symptoms is considered a forerunner for heart disease and diabetes.

For the study, participants with at least two of these signs were considered to have metabolic syndrome.

Participants came from the long-running Whitehall II study, which began in 1985 and follows British civil servants from middle age onward.

For the new findings, researchers followed more than 6,400 people aged 39 to 63 for 10 years. At the start of the study, they recorded patients' risk factors, including weight.

During the follow-up decade, participants also took tests on memory, reasoning and overall mental function at three intervals, according to the report published in the Aug. 21 issue of the journal Neurology.

People with metabolic syndrome who were also obese saw a more rapid decline -- 22.5 percent faster -- in their mental function than those who weren't obese and didn't suffer from the syndrome.

Moreover, those who did not have metabolic syndrome but were obese also saw mental function decline more quickly than participants who were not obese.

Obesity is a known risk factor for many adverse health outcomes, including dementia. It typically is accompanied by metabolic syndrome, Singh-Manoux said. This, however, is not always the case, leading to the concept of so-called "metabolically healthy obesity," she said.

"Some research suggests this type of obesity carries less health risk, but the evidence is far from clear," Singh-Manoux said.

"Our results show this not to be the case for mental function," she said. "Obesity, in those who were metabolically healthy and unhealthy, was associated with poor mental function at the start of the study and greater decline over 10 years."

Dr. Richard Lipton, professor and vice chairman of neurology at Albert Einstein College of Medicine in New York City, said that "this study suggests that taking the steps recommended to prevent heart attack and stroke in midlife, including controlling body weight, high blood pressure, diabetes and lipid profiles, may also have a beneficial effect on cognitive function late in life."

Although more studies are needed, people should heed the advice on how to protect their hearts, Lipton said, which will, in turn, protect their brains as well.

"Maintaining normal body weight while preventing or treating abnormalities in blood pressure, glucose regulation and lipids may provide a therapeutic twofer, protecting the heart and brain," he said.

More information

To learn more about obesity, visit the U.S. National Library of Medicine.

SOURCES: Archana Singh-Manoux, Ph.D., research director, Center for Research in Epidemiology & Population Health, INSERM, Paris; Richard Lipton, M.D., professor, vice chairman, neurology, Albert Einstein College of Medicine, New York City; Aug. 21, 2012, Neurology

Last Updated: Aug. 20, 2012

Copyright © 2012 HealthDay. All rights reserved.

Harvard Report - Weight Loss Surgery, the Brain and Addiction

Alcohol abuse after weight loss surgery?

Researchers gather at Radcliffe to investigate gut-brain communication

By Alvin Powell

Harvard Staff Writer

Monday, July 30, 2012

Photos by Thomas Earle/Harvard Staff Photographer

The Radcliffe Institute for Advanced Study brought together scientists, whose research is relevant to obesity and addiction, to investigate an increased incidence of alcohol abuse among those who have had the surgery and, through that, the possible impact of the surgery on the brain circuits that control addiction.

Asmall group of scientists gathered last week at the Radcliffe Institute for Advanced Study to share ideas about a medical mystery: the increasing evidence that some types of weight loss surgery affect not just the stomach, but the brain as well.

The procedures, two types of bariatric surgery known as gastric bypass andsleeve gastrectomy, physically bypass or remove a portion of the stomach. Used only for obese patients whose weight threatens their health, the surgeries have proven dramatically effective, reducing patients’ excess weight in the months and years following surgery by 50, 60, and even 80 percent.

The procedures were initially thought to work through simple physical means: Patients with smaller stomachs wouldn’t be able to eat as much, allowing them to lose weight and also giving them an opportunity to reform eating habits.

James Mitchell, one of the authors of the JAMA study, said research showed that the risk factors for developing alcohol problems post-surgery include pre-surgery smoking, recreational drug use, and regular alcohol use.

But in recent years, scientists have noticed side effects of the surgery that hint at something entirely different: that the surgery somehow affects not just the stomach, but the body’s broader metabolism and even the brain.

The Radcliffe event brought together scientists whose research is relevant toobesity and addiction to investigate an increased incidence of alcohol abuseamong those who have had the surgery and, through that, the possible impact of the surgery on the brain circuits that control addiction.

The effect, reported in a handful of studies in recent years, was highlighted in June, when a large survey of more than 1,900 bariatric surgery patients was published in the Journal of the American Medical Association (JAMA). The survey showed that alcohol abuse increased significantly in the second year following gastric bypass surgery and that, among those reporting post-surgery alcohol problems, 60.5 percent hadn’t had drinking problems before.

The seminar was organized by two assistant professors at Harvard Medical School (HMS), Janey Pratt, co-director of the Weight Center at Harvard-affiliated Massachusetts General Hospital and assistant professor in surgery, and Stephanie Sogg, staff psychologist at the MGH Weight Center and assistant professor in psychology.

The first day was dominated by presentations from the 18 invited scientists on everything from background on the surgical procedures to the use of functional magnetic resonance imaging to monitor brain activity to the latest work on the chemical signals involved in hunger, fullness, the pleasurable aspects of eating, and addiction. The second day focused on future research, with discussion of collaborative projects and potential funding sources.

“It was the first time everybody was in one room together. The intellectual energy, it was amazing, one idea launched into another,” Sogg said. “The whole thing was just remarkable.”

“It was the first time everybody was in one room together. The intellectual energy, it was amazing, one idea launched into another,” said Stephanie Sogg (right), staff psychologist at the MGH Weight Center. Joining Sogg was Nicole Avena (left), a research neuroscientist and expert in the fields of nutrition, diet, and addiction.

James Mitchell, one of the authors of the JAMA study and chair of the Department of Clinical Neuroscience at the University of North Dakota Medical School, described the results of the recent report and of another published in 2001. The 2001 paper showed that one in five bariatric patients reported getting drunk on fewer drinks and about a third reported getting intoxicated in less time. A number of respondents, concerned about the effects they were seeing, decreased or stopped drinking.

The more recent JAMA study showed that the risk factors for developing alcohol problems post-surgery include pre-surgery smoking, recreational drug use, and regular alcohol use, Mitchell said.

A pair of researchers from the University of Cincinnati — Associate Professor of Psychiatry Stephen Benoit and research scientist Jon Davis — presented an overview of recent work connecting obesity and addiction. Because people have to eat to survive, many in the addiction field have resisted the idea offood addiction. That resistance has weakened since 2000, in response to studies investigating “hedonic eating” and dopamine release in the brain.

Research highlighted by Benoit and Davis showed that leptin, a hormone that inhibits appetite, also affects the release of dopamine, a key player in drug abuse circuitry. Other hormones possibly implicated in linking obesityand addiction are GLP-1, or glucagon like peptitide-1, whose levels skyrocket in patients after bariatric surgery, and ghrelin, a hormone considered a complement to leptin in controlling appetite that is produced in the part of the stomach frequently removed or bypassed in bariatric surgery.

“Clearly, being obese is affecting the addiction circuitry,” Benoit said.

New research by Davis, Benoit, and colleagues complicates the picture, highlighting how gastric bypass surgery can not only induce excessive drinking in people without alcohol problems before surgery, but can also reduce drinking in people who reported some level of alcohol consumption before surgery.

The study, which appeared in March in the journal Biological Psychiatry, surveyed more than 6,000 patients who received gastric bypass surgery and found that a significant number who reported occasional to frequent alcohol use before surgery reported decreased use afterward. The researchers then used lab rats to understand which hormones were involved, showing thatGLP-1 is implicated in inducing alcohol aversion while ghrelin can restore the rats’ appetite for alcohol.

Ashley Gearhardt, who is set to start as an assistant professor at theUniversity of Michigan in the fall after earning a doctoral degree from Yale University, used the existing psychiatric definition of substance dependenceto develop a diagnostic survey for “food addiction,” the Yale Food AddictionScale.

Gearhardt described the scale, already being used by researchers as a tool to diagnose food addiction, and outlined the results of initial studies using it.

One study of 233 normal-weight, college-aged women showed that 11.4 percent of them met the definition of food addiction, said seminar participant Ashley Gearhardt.

One study of 233 normal-weight, college-aged women showed that 11.4 percent of them met the definition of food addiction, Gearhardt said. Researchers also evaluated the scale against similar diagnostic criteria for binge-eating disorder to make sure they’re measuring something different. They found, in a study of 81 obese people seeking treatment for binge eating, that just 57 percent met the definition of food addiction. This finding shows, Gearhardt said, that while there is overlap, the two conditions are separate. In other research, Gearhardt and colleagues demonstrated similarities in brain activation between people who are substance dependent and those with high measures on the food addiction scale.

Mitchell suggested that researchers pay attention to cognitive decline and liver disease, because liver functioning has been shown to temporarily decline after surgery and because physicians are starting to see improving cognitive function in patients after bariatric surgery. Obesity has been linked to cognitive decline and an increased risk of Alzheimer’s disease.

During discussions about future courses of research, the scientists agreed that weight loss patients should be followed over longer periods of time and that more work is needed on the neural mechanisms linking obesity and the brain.

Bariatric surgery “was seen as merely an anatomical restriction,” Sogg said. “We now know that is the least of the reasons why it works. We have a pretty good idea that the real mechanism of action is all about gut-brain communication.”