Excess pounds may be contagious

NEW YORK – Obesity may be contagious because most people feel good about themselves if they are about as heavy as the people around them, according to new research from an international team of economists.

This could explain the rapid rise in the prevalence of overweight around the world, the researchers say. That is, the norm that most people compare themselves to has become fatter and fatter, feeding a cycle of "imitative obesity."

"What we're finding is that human beings are probably driven tremendously by comparison. Unless you understand those comparisons, you're not going to understand the rate of obesity," Dr. Andrew J. Oswald of the University of Warwick in the UK told Reuters Health. "Understanding the sociology of obesity is much more important than understanding the biology."

Last year, Oswald and his team note, Drs. Nicholas Christakis of Harvard and James Fowler of the University of California, San Diego published a study showing that people were more likely to become obese if their friends and family members were heavy.

In the current analysis, which they presented at the National Bureau of Economic Research conference July 25 in Cambridge, Massachusetts, Oswald and his colleagues attempt to use an economic model to show why this happens.

They analysed data from several sources on body mass index (BMI) and people's perception of their weight for 29 European countries.

More than one-third of Europeans think they are too fat, the researchers found, and people who are more educated were more likely to think they are overweight.

The researchers also found that for women, satisfaction with their weight depended on their own BMI in relation to the average BMI for a woman of their own age living in the same country.

For their part, men who were overweight tended to be happier if the people around them were overweight too.

The link between people's relative BMI and their general life satisfaction is likely unconscious, according to Oswald. "They may not be aware of it. Our computers can trace out these patterns without the individual necessarily knowing them."

So the average person doesn't mind being overweight if people around him are too; hence he is "keeping up with the fat Joneses," Oswald explained.

However, for "high-status" individuals, being thin is becoming more and more important, he added; this may explain the rise of super-skinny models and actresses, as well as the prevalence of anorexia among upper-middle class girls and boys.

It might be possible to change people's weight-related norms by having them look at images and movies from decades ago — when people were, on average, 20 pounds lighter, Oswald suggested.

Childhood stress tied to mental disorders

NEW YORK – Adults in treatment for severe mental disorders report greater levels of childhood stress than adults without psychiatric disorders, researchers from Germany found in a study they conducted.

A burgeoning number of studies suggest that adverse or traumatic experiences during childhood influence adult psychopathology, Dr. Brigitte Rockstroh, of the University of Konstanz, and colleagues note in the journal BMC Psychiatry.

They sought to further clarify this influence by comparing lifetime stress levels among 96 adults with major depression, schizophrenia, drug addiction, or personality disorder and 31 non-psychiatric adult subjects.

The investigators used two stress screening scales to measure adverse experiences when study participants were younger than six years (early childhood), before the onset of puberty, and during adulthood.

Rockstroh's group found indications that childhood is a critical developmental period, in that all study participants showed negative effects related to high stress levels during childhood and before puberty, but not adulthood.

Psychiatric patients, however, appear to be more negatively affected by early life stress, as they scored about four and six points higher in measures of early childhood and pre-pubertal stress, respectively, relative to non-psychiatric subjects.

Yet, measures of adulthood stress did not differ between groups.

Heart disease tied to cognitive problems

NEW YORK – Results of a study in the European Heart Journal indicate an association between heart disease and lower thinking or "cognitive" performance in middle-aged adults.

Using data from the Whitehall II study, Dr. Archana Singh-Manoux, of INSERM, Cedex, France, and colleagues examined the association between heart disease and cognition in 10,308 subjects who were 35 to 55 years of age when the study began in the late 1980s.

Heart attacks and other related heart problems were recorded up to 2004, at which point 5837 subjects had completed six cognitive tests.

Men and women who developed heart disease scored lower on a number of cognitive tests, particularly those involving reasoning and vocabulary, than did their peers without heart disease.

Moreover, there was evidence, at least in men, that the longer the heart disease was present, the greater the impairment in thinking.

Acid reflux therapy can be cost-effective

NEW YORK – In patients taking aspirin to lower their risk of having a heart attack or stroke, lifelong therapy with a proton pump inhibitor (PPI), which includes drugs such as Nexium or Prilosec, can be a cost-effective means of reducing the risk of upper gastrointestinal bleeding, according to a new report.

For patients with a high risk of gastrointestinal bleeding, this treatment is nearly always cost effective, the report indicates. For patients with only an average risk for bleeding, however, this therapy is only cost effective if PPIs are purchased at over-the-counter costs, rather than as a prescription. Dr. Sameer D. Saini, from the University of Michigan Medical School in Ann Arbor, and colleagues developed a statistical model to assess the cost-effectiveness of PPI therapy in coronary heart disease patients who were at least 50 years of age and were taking aspirin. In a second analysis, the researchers assumed that the patients began taking aspirin with or without PPI therapy at 65. In addition, they also assumed that the patients had an average risk of bleeding and that PPI therapy was 66-percent effective and cost $250 annually.

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