Even a moderate bulge at the waist can make a person more susceptible to cardiovascular diseases, says a new study.
The research, conducted at the Southwestern Medical Center in the University of Texas, suggests that accumulating several inches at the waist noticeably boosts the risk of unhealthy plaque build-up in the arteries of the heart and the rest of the body. The plaque build-up occurs even if a person's body weight falls within the normal range.
"In our thirties and forties, we often gain three to four inches in the midsection. It's a day-to-day, meal-to-meal battle, but it is worth fighting. Even a small pot belly puts us at higher risk when compared to a flat tummy," said James A de Lemos, director of the Coronary Care Unit at the Southwestern Medical Center.
For the study, Dr de Lemos and his colleagues assessed data from the ongoing Dallas Heart Study. The study is evaluating risk factors for heart diseases in a multi-ethnic, urban population with a median age of 45.
The new study focused on a group of 2,744 participants. Non-invasive imaging tests were conducted on the participants to look for early signs of plaque build-up in the arteries. Accumulation of plaque signals an increased risk of developing cardiovascular diseases later in life.
Electron-beam computed tomography was used to spot calcium deposits in the arteries of the heart. These deposits indicate the beginning of atherosclerosis, or the so-called hardening of the arteries, and can be detected years before a person experiences heart problems.
Researchers then looked at the relationship between a person's body shape and the early signs of arterial disease. They found that the chances of calcium being found in the arteries of the heart grew in direct proportion to increases in the waist-to-hip ratio.
Moreover, researchers found that people with the largest WHR were nearly twice as likely to have calcium deposits in their coronary arteries as those with the smallest WHR.
The relationship between WHR and arterial plaque remained strong even after other risk factors like blood pressure, diabetes, smoking and high cholesterol levels were taken into account.
"Middle-aged spread is not healthy. We don't have to clean our plates. It's better to throw food out than add it to our waists," said Dr de Lemos.
Raimund Erbel, a doctor from the Essen Heart Center, explained that using the WHR measurement to estimate cardiovascular risks has certain clinical advantages.
"The WHR can be easily measured. It only takes a few moments but gives more precise information on the presence of coronary artery calcium than body mass index or waist circumference. Other measures of obesity do not discriminate beyond traditional risk factors, but WHR does," said Dr Erbel.
"The results are astonishing and may be influenced by the age distribution of the study. With advancing age, the likelihood of coronary artery calcium increases more in men than in women," he added.
The study appears in the August 21 issue of the Journal of the American College of Cardiology.