Obesity
Obesity gene linked with calorie consumption
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The gene mutation associated with obesity—the FTO gene—does not appear to regulate how calories are burned calories, but may influence the amount and choice of food consumed, according to a UK report published in The New England Journal of Medicine.
FTO gene mutations have shown the strongest association with obesity to date, Dr. Colin N. A. Palmer at the University of Dundee, Scotland, and colleagues point out. Yet, the mechanisms by which FTO mutations promote obesity have been unclear.
In 2,726 Scottish children between 4 and 10 years of age, the researchers tested for the FTO mutation rs9939609. All of the children underwent height and weight measurements. In 97 subjects, the link between the FTO mutation and amount of body fat, calories burned and food consumed was explored.
Smoking’s effect on child weight may vary by race
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Studies have linked prenatal smoking to a higher risk of childhood obesity, but new findings suggest that effect may vary based on race and ethnicity.
In a study of more than 155,000 preschool children, U.S. researchers found that the link between mothers’ smoking during pregnancy and their children’s risk of obesity was most clear among white families.
In contrast, only heavy prenatal smoking was tied to childhood obesity among African Americans. And there was no clear evidence that it raised the odds of obesity among children of Hispanic, Native American or Asian descent.
Obesity, lack of exercise reported in asthmatics
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Study findings suggest less than one quarter of asthmatic adults meet national exercise guidelines and, among this group, obesity may be a greater exercise deterrent actual asthma symptoms.
People with asthma may get caught in a vicious cycle, note Dr. Carol A. Mancuso and colleagues from Weill Cornell Medical College and the Hospital for Special Surgery in New York City.
“Obesity leads to worse asthma, which can be associated with less exercise, which predisposes to obesity and long-term (worsening) asthma,” Mancuso told Reuters Health.
Sealing off portion of intestinal lining treats obesity, resolves diabetes in animal model
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Lining the upper portion of the small intestine with an impermeable sleeve led to both weight loss and restoration of normal glucose metabolism in an animal model of obesity-induced diabetes. Investigators from the Massachusetts General Hospital (MGH) Weight Center and Gastrointestinal Unit report in the journal Obesity that the procedure reproducing several aspects of gastric bypass surgery led to a significant reduction in the animals’ food intake and a resolution of diabetes symptoms. The study, which has received early online release, is the first controlled test of a new procedural approach to treating obesity.
“This is a clear proof of principle that the human version of this device may be an effective treatment for obesity and diabetes. The clinical device would be placed endoscopically, making it far less invasive than surgical therapies,” says Lee Kaplan, MD, PhD, director of the MGH Weight Center, who led the study. “The next step will be to complete large-scale controlled trials of this procedure in human patients. We also need to learn more about how this device affects the complex interplay between receptors that line the stomach and intestine – which are stimulated by ingested food – and the brain, pancreas, liver and other organs involved in metabolism and in eating behavior.”
Several surgical procedures have been developed to treat obesity and its complications, such as type 2 diabetes. The most common operation – Roux-en-Y gastric bypass – has five key components: isolation and reduction in size of the upper portion of the stomach, exclusion of the rest of the stomach from the flow of ingested food, exclusion of the upper portion of the small intestine (the duodenum and upper jejunum) from the flow of food, delivery of undigested nutrients to the middle portion of the small intestine, and partial severing of the vagus nerve, a key conduit between the gastrointestinal system and the brain in the control of appetite, digestion and glucose metabolism.
Obese kids’ artery plaque similar to middle-aged adults
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The neck arteries of obese children and teens look more like those of 45-year-olds, according to research presented at the American Heart Association’s Scientific Sessions 2008.
“There’s a saying that ‘you’re as old as your arteries,’ meaning that the state of your arteries is more important than your actual age in the evolution of heart disease and stroke,” said Geetha Raghuveer, M.D., M.P.H., associate professor of pediatrics at the University of Missouri Kansas City School of Medicine and cardiologist at Children’s Mercy Hospital. “We found that the state of the arteries in these children is more typical of a 45-year-old than of someone their own age.”
Researchers used ultrasound to measure the thickness of the inner walls of the neck (carotid) arteries that supply blood to the brain. Increasing carotid artery intima-media thickness (CIMT) indicates the fatty buildup of plaque within arteries feeding the heart muscle and the brain, which can lead to heart attack or stroke.
Obesity, other health problems delay MS diagnosis
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People with pre-existing medical conditions, such as obesity, and vascular problems such as diabetes, high blood pressure or high cholesterol, may experience a delay in being diagnosed with multiple sclerosis (MS), or experience an increase in severity of the disease at diagnosis, according to a study published in the October 29, 2008, online issue of Neurology®, the medical journal of the American Academy of Neurology.
“Our study suggests that doctors who treat people with chronic diseases should not attribute new neurological symptoms such as numbness and tingling to existing conditions without careful consideration,” said study author Ruth Ann Marrie, MD, PhD, of the University of Manitoba in Winnipeg, Canada, and member of the American Academy of Neurology.
For the study, researchers examined the records of 8,983 people who had been diagnosed with MS. Of those, 2,375 were further classified as having mild, moderate or severe disability within two years of diagnosis. This well-characterized group was asked about pre-existing health conditions, their smoking status and weight history.
Gastric bypass cuts heart risks
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The risk faced by obese people of having a heart attack or other cardiovascular “events” is reduced substantially after they undergo gastric bypass surgery to lose weight, according to a recent study.
The take-home message is that “bariatric surgery can be considered as a means to reduce cardiovascular risk (in obese patients) after conservative treatment options have failed,” Dr. John A. Batsis told Reuters Health.
Batsis, at Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire and his colleagues identified six studies that looked at cardiovascular risk after bariatric surgery for obesity. The risk was estimated from standard tables that assigned a score for factors such as weight, blood pressure and cholesterol levels.
New Target for Obesity-Related Insulin Resistance, Type 2 Diabetes
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Building on mounting evidence that implicates infection-fighting cells found in obese fat tissue in the growing problem of insulin resistance and Type 2 diabetes, researchers at the University of California, San Diego, School of Medicine have identified a particular subset of cells that are linked to obesity-associated insulin resistance, and that offer a promising new target for the treatment of diabetes. They showed that depletion of these cells, called CD11c-positive, in obese mice resulted in a reversal of obesity-associated insulin resistance.
The study, led by Jaap Neels, Ph.D., formerly of UC San Diego School of Medicine and now at the Université de Nice-Sophia Antipolis, and Jerrold Olefsky, M.D., Distinguished Professor of Medicine and Associate Dean for Scientific Affairs at UC San Diego, will be published in the October 8 issue of Cell Metabolism.
Obese adipose, or fat, tissue is characterized by the presence of macrophages, specialized cells that usually fight infection. Adipose tissue macrophages (ATMs) accumulate in fat tissue as body weight increases. Growing evidence shows that ATMs are a significant contributor to inflammation in obesity – inflammation that leads to insulin resistance, resulting in Type 2 diabetes.
Parents foster significant misperceptions of children’s weight
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Results of a survey presented at the American College of Gastroenterology’s 73rd Annual Scientific Meeting in Orlando revealed that many parents do not accurately perceive their children as overweight or at risk for adulthood obesity. Obesity in the United States is often accompanied by an increased risk of gastrointestinal diseases and has emerged as a major health concern, particularly the issue of obesity among children and adolescents.
Researcher Rona L. Levy, Ph.D. and her colleagues at the University of Washington in Seattle and the University of Minnesota measured parental perceptions of their children’s current weight and perceived risk for developing obesity as an adult.
Forty-six parents of children ages 5 to 9 with a body mass index (BMI) in the 70th percentile or higher were recruited for the study. Child height and weight were measured during a routine pediatric clinic visit. Parents were mailed a series of questionnaires, which included questions on their perception of their child’s current weight, and whether they perceived that their child was at risk for developing obesity as an adult.
Steroids Not as Effective in Obese Asthma Patients
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Glucocorticoids, the primary controller medication for asthma, are 40 percent less effective in overweight and obese asthma patients than in those of normal weight, according to researchers at National Jewish Health, in Denver. The study also identified a potential mechanism involved in the resistance, which suggests therapeutic targets for future medications.
The study, by Associate Professor of Medicine E. Rand Sutherland, M.D., M.P.H., and his colleagues at National Jewish Health, appears in the first issue for October of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
“This study identifies what could be a significant issue for the 20 million Americans with asthma; specifically, the main controller medication might be less effective if you are overweight or obese,” said Dr. Sutherland. “These findings should spur doctors to carefully evaluate response to treatment in overweight and obese asthmatics and consider optimizing therapeutic regimens as indicated. We also hope they will spur additional research into the treatment of obese patients with asthma.”
Obese have minimal heartbeat response to stress
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Contrary to their expectations, British researchers have found that when exposed to psychological stress, obese people show smaller changes in their heart rate compared with normal-weight individuals.
Dr. Douglas Carroll at the University of Birmingham, and colleagues there and at the University of Glasgow, examined the association between obesity and the magnitude of heart reactions to stress in 1,647 adults living in the community.
Blood pressure and heart rate were measured at rest and in response to psychological stress—performing mental math problems under a time deadline. Measurements were taken when the study began and 5 years later.
Insurers recoup obesity surgery cost in 2-4 years
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Insurers recoup the costs of weight-loss surgery within two to four years as obese patients become healthier and have fewer medical problems, researchers said on Wednesday.
The findings show that bariatric surgery, an increasingly popular operation, benefits patients’ health and saves money, according to Pierre-Yves Cremieux of the economic consulting firm Analysis Group and the University of Quebec at Montreal, who led the study.
Bariatric surgery alters the digestive system’s anatomy, reducing the volume of food that can be eaten and digested. The most common form is gastric bypass, which makes the stomach smaller and permits food to bypass part of the small intestine.
Obesity not a red flag for spotting diabetes
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Obese people with diabetes are just as likely to go undiagnosed as their slimmer peers with the disease, Harvard Medical School researchers report.
It’s well recognized that obesity increases the likelihood of developing diabetes, yet “obesity does not increase the likelihood that an individual’s diabetes will be diagnosed,” Dr. Christina C. Wee and her colleagues from Harvard and Beth Israel Deaconess Medical Center in Boston report.
There is no consensus on who should be screened for diabetes, Wee and her team note in their report in the medical journal Diabetes Care. Early diagnosis of diabetes is particularly important for obese people, they add, because research shows they are less likely to be offered the preventive care that can help stave off serious complications of the disease.
Health risk behaviors associated with lower prostate specific antigen awareness
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According to a study conducted at Columbia University Mailman School of Public Health, health risk behaviors such as smoking and obesity are associated with lower awareness of the Prostate Specific Antigen (PSA), which could lead to a lower likelihood of undergoing actual prostate cancer screening. Although previous studies have explored predictors of PSA test awareness, this is the first research to focus on health risk behaviors, such as smoking, physical inactivity, obesity, and excessive alcohol consumption. The study findings were reported in the August issue of The Journal of Urology.
Awareness of PSA testing is considered an important cognitive precursor of prostate cancer screening and it was found to contribute to differences in prostate cancer screening rates. Earlier studies have suggested that persons who seek out cancer information are more likely to acquire knowledge, demonstrate healthy behaviors, and undergo cancer screening. According to the Mailman School study, a quarter of the men older than 50 years without a history of prostate cancer who were among the population of 7,000 men studied, remain unaware of the PSA test.
“Our primary findings suggested that smoking, physical inactivity and obesity are inversely associated with awareness of the PSA test. These risk behaviors are linked with higher prostate cancer morbidity and mortality,” said Firas S. Ahmed, MD, MPH, Mailman School of Public Health, and first author. This finding may be due to a general lack of concern about health maintenance or less interactions with health care providers by smokers, according to Dr. Ahmed.
“Good” fat may be new weapon in obesity fight
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A new understanding of the origins of brown fat cells—the “good” kind of fat that burns energy and keeps us warm—may lead to new treatments for obesity, two research teams reported on Wednesday.
Researchers at the Dana-Farber Cancer Institute in Boston said they used a single molecular switch to turn immature muscle cells into brown fat cells in the lab, suggesting that brown fat may be more akin to muscle cells than conventional white fat cells.
A second team from the Joslin Diabetes Center in Boston, found a protein important for bone growth helped promote the development of brown fat tissue in mice.
