Wednesday, September 12, 2007

Shape matters for heart risk, weight doesn't

woman
When it comes to the risk of a heart attack, only the waist to hip ratio is important but not the body mass index, according to the Dallas Heart Study. More than two thousand Texans have been examined, using various measures of obesity and computer tomography for assessing the calcification of coronary arteries. The more calcium is found in the coronaries, the more serious is the heart disease and the higher the risk of a heart attack.

Main results: The most widely used obesity scale, body mass index (BMI), is only marginally linked to coronary calcium, and this link disappears when other risk factors are taken into account. The same is true for waist circumference. Only the waist to hip ratio (WHR) shows a relation to coronary calcium, with a double risk for those with the highest WHR values, compared to those with the lowest values.

Not the fat matters but where it deposits

The woman in our picture has a waist to hip ratio of about 70 percent which is an ideal value for a woman - similar to Marilyn Monroe, Sophia Loren and the Venus of Milo. For a man, the best value is about 90 percent. Waist to hip ratio is measured as follows: Take a non stretchable tape, measure the waist at its narrowest point, usually above the belly button, and the hips at the widest point of the hip bones. Then divide the waist circumference by the hip circumference.

Just a link but not a cause

A fat belly, but not fat in other places of the body, is linked to the risk of a heart attack. This is just a link, not more. It does not mean that fat at the belly (but not at other places) is doing harm to the arteries. In fact, a study has found that belly liposuction surgery does not improve heart risk factors. Thus, it is more reasonable to assume that certain causes such as genetic disposition, nutrition and lack of exercise may lead to belly fat on the one hand and to heart disease on the other hand.

Photo credit: flickr.com/photos/7258769@N02/1024217616/

No comments: