Sporting a pot-belly, that little pouch of abdominal fat that hangs down over your pants or bathing suit? You may be at an increased risk of heart disease, U.S. researchers say.

People with the highest hip-to-waist ratios were almost twice as likely to have calcium deposits in their coronary arteries as those with the smallest waist-to-hip ratios.
(CBC)

A new study indicates that having a high waist-to-hip ratio, measured by a tape measure, can indicate you're more susceptible to heart disease. And even a little pot-belly can raise the odds.

"Your chances of having buildup of plaque in the arteries of the heart or the arteries of the aorta go up with even a few inches," James deLemos, one of the study's researchers and the director of the Coronary Care unit at the University of Texas Southwestern Medical Centre, told CBCNews.ca.

The study appears in the Aug. 21 issue of the Journal of the American College of Cardiology.

Calcium deposits high when pot-belly present

Researchers examined a group of 2,744 participants with a median age of 45, tracking their body-to-mass index (BMI), blood pressure, cholesterol levels and other health indicators.

The participants were then given electron-beam computed tomography scans to check for calcium deposits in the arteries of the heart.

According to deLemos, these types of deposits act as a marker for hardening of the arteries and heart disease.

Magnetic resonance imaging was also used to look for clogged arteries in the walls of the aorta.

Researchers then compared a person's body shape and early signs of heart disease and found a strong correlation. The higher the person's waist-to-hip ratio, the greater the calcium buildup in the arteries.

People with the highest waist-to-hip ratios were almost twice as likely to have calcium deposits in their coronary arteries as those with the smallest waist-to-hip ratios.

As well, blood pressure, diabetes, age, smoking and high cholesterol levels played less of a role in heart disease than did the actual waist-to-hip ratios, the researchers found.

Viewing fat in a whole new light

The discovery alters the way abdominal fat is perceived, DeLemos said.

"I remember people in medical school thinking fat was just this inert blob. Now researchers have shown fat is a very active tissue. In fact, the central fat that accumulates in the central regions of the body tends to be particularly active from a metabolic standpoint."

'I remember people in medical school thinking fat was just this inert blob. Now researchers have shown fat is a very active tissue.'—James deLemos

He said fat deposited in hips, buttocks and other regions doesn't seem to play the same metabolic role.

DeLemos said the findings show that a waist-to-hip measurement yields more clues about a person's heart health than traditional weight measurements, such as waist circumference alone or BMI.

"In terms of discriminating between who gets and who doesn't get atherosclerosis, definitely the tape measure gives you more information than the scale does," he said.

"The scale is not as useful because if you're in really good shape and you gain muscle, you may have a very low body weight but be at high risk of atherosclerosis."

The good news, deLemos said, is that a pot-belly doesn't guarantee full-fledged heart disease by any means.

"This is just a piece of the puzzle," he said.

But getting rid of the little paunch might be a good idea from a prevention standpoint, he advised.

"I think you can be fit and have a pot-belly. But it's best to start working on that the best you can."

Heart disease top killer of Canadians

Cardiovascular disease accounts for the death of more Canadians than any other disease. In 2002 (the latest year for which Statistics Canada has data), cardiovascular disease accounted for 74,626 Canadian deaths, according to the Heart and Stroke Foundation of Canada.

Thirty-two per cent of all male deaths in Canada in 2002 were due to heart diseases, diseases of the blood vessels and stroke. For women, the toll was even higher — 34 per cent of all female deaths in 2002 were due to cardiovascular disease.