Obese with strong heart beats those thin and weak

NEW YORK (Reuters Health) - For overweight people with heart disease, improving their physical fitness could pay big dividends.

A new study has found that fitness, not body weight, is a more important predictor of whether people with clogged blood vessels in their heart will die in the relatively near term.

Being overweight, or even obese, but having a heart that could tolerate heavy exercise was markedly better than being a lean person who panted from walking up a hill.

Not surprisingly, the study also showed that obese heart patients who were least physically fit, and those with large amounts of fat concentrated around their hips and abdomen, were much more likely to die during the 14-year study period compared to their fitter, more slender peers. The combination of poor fitness and that kind of so-called "central obesity" was even more dangerous, raising the risk for death roughly sevenfold, the researchers said.

"The bottom line here is that fitness modulates the prognosis in patients with coronary artery disease according to their body weight," study leader Dr. Francisco Lopez-Jimenez, a heart specialist at Mayo Clinic, in Rochester, Minn., told Reuters Health. "To have a low fitness and to have central obesity seems to be a pretty bad combination."

For the new study, published in the American Heart Journal, Dr. Lopez-Jimenez and colleagues studied 855 men and women enrolled in a cardiac rehabilitation program. In the past, all of them had either had heart attacks, or bouts of severe chest pain related to heart problems. Some had undergone medical or surgical procedures to help unclog the blood vessels in the heart.

To assess patients' fitness, doctors had them walk on treadmills. They were each assigned a score based on the distance they could walk, and their ability to take in oxygen while exercising - both key aspects of physical fitness.

The researchers used body-mass index - a ratio of height to weight - to determine whether patients were overweight or obese.

Patients who were fit and relatively thin had the lowest odds of dying in the study period and constituted a "control" group. Fit but overweight patients were about twice as likely to die, while those who were fit but obese had three times the risk of death compared to the fit and thin control group.

Things got more complicated for the unfit. Patients with poor fitness scores who were overweight were nearly 7 times more likely to die during the study compared to the control group. But normal-weight people who were unfit were nearly 10 times more likely to die, the researchers found.

In other words, as long as a person with heart disease stays active, being obese-at least according to their body mass index-does not seem to make their prognosis worse. On the other hand, having too much abdominal fat is a problem even for people who can withstand a lot of exercise.

"You are better off if you are fit, and you are better off if you have a shorter belt," said Eric Ravussin, an obesity expert at the Pennington Biomedical Research Center in Baton Rouge, LA.

Ravussin offered several explanations for why obesity did not seem to have the impact one might expect. Obese people typically go to the doctor often, and thus are more likely to be tested, and treated, for high cholesterol, a leading risk factor for heart attacks and strokes, he said. The new study did not look at how many cholesterol-lowering medications patients were taking.

Compared to thin people, the obese have more energy reserves to help them weather serious illnesses, Ravussin noted. Also, studies have shown they appear to be better able to suppress inflammation linked to heart and vessel damage - although the reasons for that aren't clear.

Whatever the case, Lopes-Jimenez said, the lesson for patients is clear: try to improve your physical fitness. "It is much easier to become fit than it is to become slim," he said. "Anybody who has gone into an exercise program would agree with that."

SOURCE: Reuters, Adam Marcus 3/31/11: bit.ly/i25TCj American Heart Journal, March 2011.

Obesity Follows Into Adulthood

Obesity often follows the young into adulthood
People who were obese between the ages of 12 and 21 are seven times more likely than normal-weight or overweight peers to develop severe obesity by the time they reach their late 20s to early 30s, a study finds.

Some adolescent memories — prom dates, fashion choices, Facebook postings — tend to fade and, mercifully, disappear in the transition to adulthood. But a study released Tuesday finds that one increasingly common source of teen angst — obesity — has a cruel knack for following adolescents into their adult years, then tightening its grip.

The result not only confers profound health risks for teens whose excess weight follows them and accelerates into adulthood, it also spells a looming public health disaster in a country where almost 1 in 5 adolescents is obese, experts say.

By the time they reach their late 20s to early 30s, people who were obese between 12 and 21 are more than seven times more likely than normal-weight or overweight peers to develop severe obesity — defined as having a body mass index, or BMI, of 40 or more — according to the study published in the Journal of the American Medical Assn.

For women and for ethnic minorities, the likelihood of proceeding from adolescent obesity to adult severe obesity is particularly pronounced. Among women, 51.3% of those who had been obese when they were younger became severely obese adults (for men, the figure was 37.1%). Among African American women, 52.4% who had been obese in earlier years went on to become severely obese.

By comparison, 7.9% of all participants in the study, and less than 5% of those whose weight was in the normal range, became severely obese in adulthood.

The authors, epidemiologists based in North Carolina, estimated from their findings that 1 million Americans who were between the ages of 12 and 21 in 1996, when the study began, became severely obese adults. As they did so, they took on the increased risk of developing obesity-related conditions such as cardiovascular disease, Type 2 diabetes, certain cancers and musculoskeletal pain.

The report comes against the backdrop of evidence that the ranks of the severely obese — typically, those who carry at least 80 to 100 pounds of excess body weight — are rising faster in the U.S. population than those classified as moderately obese. Given the scarcity of solutions — drugs and diet-and-exercise interventions have proved less safe and effective than experts had hoped — the authors note that "prevention is critical."

For those already obese, the authors said, it is important to identify those at greatest risk of becoming severely obese and focusing weight-loss programs on them.

The investigation tracked 8,834 participants ages 12-21 at the study's start for 13 years. Because of the long follow-up, the study provides a clearer picture than most of obesity's progression in individuals of different genders, ages and ethnicities, said lead author Penny Gordon-Larsen, an epidemiologist with the Carolina Population Center at the University of North Carolina.

In particular, the findings underline that for children who struggle with their weight, the transition to adulthood can be a particularly perilous crossing, Gordon-Larsen said.

Obese teens increasingly are steered toward riskier measures to avert future health problems, including bariatric surgery — a weight-loss intervention that grew sevenfold among teens between 2005 and 2007, according to a recent report. The authors of the JAMA study suggested such surgery may be justified because it "is the only treatment to have long-term success," albeit with "major potential complications."

Pediatric endocrinologist David S. Ludwig, director of Children's Hospital Boston's Optimal Weight for Life program, said the JAMA study emphasized the "critical importance" of treating childhood obesity early, before poor lifestyle habits can become deeply ingrained. Early obesity also "may produce changes in metabolism, hormones or the brain that oppose weight loss," Ludwig added.

At the same time, some experts in weight management across the lifespan said the study's usefulness was limited by its reliance on the BMI as the primary measure of an individual's healthful weight.

"I'm not a big fan of BMI, especially for kids," said Dr. David Heber, director of UCLA's Risk Factor Obesity Program. A rough measure of fat based on an individual's height and weight, the BMI can be useful for detecting population trends, but is often not the best measure of an individual adolescent's fitness or prospects of developing obesity-related health conditions, he said.

Instead, Heber prefers to measure an adolescent's fat and lean-muscle mass and calculate their relative proportions. "They'll tell you what your target weight should be," he said.

Source:Melissa Healy, Los Angeles Times, November 9, 2010