"Spare Tire" Increases Heart Disease Risk

< Aug. 11, 2010 > -- A new study finds that even a small amount of extra fat around the middle can increase the risk for high blood pressure and other heart problems because of the effect on the function of cells that line blood vessels.

The cells which line blood vessels are called endothelial cells. These cells are vital for proper functioning of blood vessels. They control the ability of the vessel to contract and dilate, which in turn controls blood flow. Damage to the endothelium can affect the functioning of the blood vessel, eventually leading to high blood pressure and blood vessel disease, according to the researchers.

The report is being released this week in the Journal of the American College of Cardiology.

"When people put on a modest amount of weight, if the fat is in the belly, those people tended to have a greater impairment of endothelial function," says lead researcher Dr. Virend K. Somers, a professor of medicine at the Mayo Clinic School of Medicine. "Endothelial function is a marker of health of the blood vessel."

"There is something about fat deposited in the belly that makes it potentially hazardous to health, because impaired endothelial function has been linked to increased risk of high blood pressure and blood vessel disease," Dr. Somers says.

Extra Weight Affects Dilation of Arteries

For the study, Dr. Somers' team randomly assigned 43 normal-weight adults to either gain about nine pounds or keep their current weight.

The researchers measured endothelial function in the brachial artery, which is located in the arm. Specifically, they assessed the ability of the artery to dilate.

Measurements were taken before the study started, after eight weeks of weight gain, and again after 16 weeks of weight loss.

The researchers found that people who gained weight showed a decrease in the ability of the artery to dilate. However, when the study participants lost the weight they had gained, the ability of the brachial artery to dilate properly returned to normal.

Even Small Weight Gains are Significant

People tend to ignore minor weight gain, such as the few pounds they can put on over the holidays, Dr. Somers says. "It's only 10 pounds, and that's not much, but even this modest amount of weight gain has potentially harmful effects for blood vessels," he says.

Dr. Gregg C. Fonarow, director of the Ahmanson-UCLA Cardiomyopathy Center at the University of California, said that "increased body fat has been linked to both premature cardiovascular disease and endothelial dysfunction."

This study nicely demonstrates that weight gain and increases in abdominal fat are directly contributing to endothelial dysfunction, he says. "Further, this endothelial dysfunction is entirely reversible after the excess weight and abdominal fat is lost through diet. This is yet another reason to maintain a healthy weight and avoid excess belly fat," Dr. Fonarow adds.

Always consult your physician or other healthcare provider for more information.

Apple or Pear: What Is Your Shape?

There is a saying about what matters in real estate: location, location, location. The same holds true for your personal real estate. When you look in a mirror, where do you see extra pounds?

Weighing too much is harmful, but the location of those extra pounds can worsen the risk. Simply put, extra weight around your middle puts you at greater risk for heart disease.

"For both men and women, abdominal fat carries the greatest health risk," says Dr. James M. Rippe, associate professor of medicine at Tufts University School of Medicine and author of 26 health and fitness books, including The Healthy Heart for Dummies. He says the so-called apple-shaped body is more dangerous because abdominal fat cells cause greater metabolic changes. Those changes can include insulin resistance (a forerunner of diabetes) and a faster heartbeat.

The body mass index (BMI) has become the standard way to learn the healthy weight for your height. In general, BMI can accurately determine if you are of normal weight, or if you are overweight or obese, but the calculation is not perfect. If you are very muscular but with little body fat, for example, your BMI may wrongly indicate that you are overweight or obese. Other people might have a normal BMI, but still have excess body fat.

Dr. Rippe says there is a less technical way to find out if you are too fat, and it is backed by a study he co-authored in a supplement to the journal Obesity Research. "Waist circumference is the best predictor of risk for heart disease," he says.

The American Heart Association and the National Heart, Lung and Blood Institute (NHLBI) recommend to keep your waist circumference less than 40 inches for men and less than 35 inches for women.

All you need to learn your waist circumference is a plastic tape measure and a half-naked body. "It's an easy measurement to take, but less than 1 percent of doctors take it," Dr. Rippe laments.

Regardless of height, if your waist measures more than 37 inches for a man and more than 31.5 inches for a woman, it's time to think about a weight-loss program, Dr. Rippe says. "You don't have to wait for it to get to that point," he adds. "The higher the numbers, the greater the risk. There's no free pass if it's slightly under."

Always consult your physician or other healthcare provider for more information.