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December 24, 2004
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  Pork on the Run    

Couch Potatoes (video) - November 30, 2001 Not only are there many people who do no exercise at all, but they also may be fooling themselves into thinking that they do.

Infectious Obesity (video) - July 05, 2001 Researchers have shown that a virus which causes obesity in animals is also contagious.

Fat Virus - July 27, 2000 Scientists have found a virus that causes obesity.


CDC on obesity

Pigs help understand couch potato diseases

Surgeon General on physical activity and health

Pig Planet: Fun Facts on Pigs

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Are you a couch potato? If so, you might learn a lesson from some couch pigs.

As this ScienCentral News video reports, scientists studying diabetes and heart disease taught some pigs to take up jogging.

Couch pigs

During the past 20 years there has been a dramatic increase in obesity in the United States.According to the Centers for Disease Control and Prevention, more than half of all U.S. adults are currently considered either overweight or obese according to measures of Body Mass Index (BMI).

If you want to see where you stand in this weight game you can calculate your BMI, which is a measure of your weight in relation to your height. Follow the steps of this simple formula:

[Weight in pounds ÷ Height in inches ÷ Height in inches] x 703


[Weight in kilograms ÷ Height in cm ÷ Height in cm] x 10,000

If your BMI is:

  • 18.5 - 24.9, you are considered Normal weight
  • 25 - 29.9, you are considered Overweight
  • 30 or greater, you are considered Obese

A Deadly Formula

Researchers are trying to understand the relationship between obesity, diabetes and coronary artery disease. Dr. Michael Sturek, professor of physiology at the University of Missouri-Columbia mentions simpler and more familiar formula: low levels of activity + high caloric intake = increased body weight.

And, Sturek adds, "in a lot of people this body weight ends up being what’s called central adiposity, or beer belly." According to Sturek, central adiposity is a much bigger health concern than lower body fat (ie, below the belt), and it can lead to Type 2 diabetes.

Central adiposity also seems to independently contribute to an increased risk of coronary disease, according to a study in the Journal of the American Medical Association. Sturek says that this pot belly fat "is actually mobilized very easily in response to hormonal stimuli and so forth. And one has then all this fatty acid and so forth in the blood. It goes right to the coronary arteries and potentially causes damage there."

Pigs like Us

Sturek’s group is studying these effects using some porkers on the run. Sturek’s group works with Yucatan pigs because their average body weight is close to ours, and their digestive and cardiovascular systems are very similar to ours. They will run on a treadmill and exercise at very similar rates to humans.

But, like us, they would love to stay inactive.

Sturek induced diabetes in the pigs and divided them into two groups. One group was allowed to stay sedentary and was given a high-fat, high-cholesterol feed. Another group hit the treadmill: one hour, four days a week, for five months.

The scientists studied the arteries of both groups using the same clinical tools used in humans. They performed coronary angiography to determine how much atherosclerosis the pigs had. They also used a more sophisticated technique called intra-vascular ultrasound, which takes pictures inside the coronary arteries. Both procedures verified that the couch potato pigs had a major amount of coronary artery disease.

The Role of Calcium

The study also revealed that calcium in the artery muscle cells regulates and participates in coronary disease in the sedentary pigs. Too much calcium both constricted the vessels, and caused out-of-control growth of cells in those vessels that blocked the opening of the artery.

The smooth muscle cells within the coronary arteries of the pigs that exercised had both lower calcium and lower calcium responses, which would result in less coronary disease.

Since they now have some clue about what cellular and molecular mechanisms cause coronary disease, Sturek hopes that a drug can be designed to alter these processes -- an "exercise pill" that could be taken by those who cannot exercise due to some disability.

Obesity and physical inactivity account for more than 300,000 premature deaths, and related healthcare costs are about $117 billion in the U.S. each year. Sturek is convinced most of this is preventable.

"It truly gets back to having an active lifestyle," he says.

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