HEALTH

NEW VITAL SIGN

Experts now believe it’s waist, not just weight, that matters

KATE LUNAU May 26 2008
HEALTH

NEW VITAL SIGN

Experts now believe it’s waist, not just weight, that matters

KATE LUNAU May 26 2008

NEW VITAL SIGN

Experts now believe it’s waist, not just weight, that matters

It seems so unfair. As countless Canadians struggle to get healthy by shedding excess flab—almost 60 per cent of the country is now overweight or obeseturns out it’s not what you weigh, but where you carry it, that’s most important. The current emphasis on healthy weight “could be extremely misleading,” says Université Lavalbased Dr. Jean-Pierre Després, scientific director of the International Chair on Cardiometabolic Risk and a leading expert in obesity. “You can be overweight and be perfectly healthy.” But the reverse is also true. Regardless of body weight, excess belly fat could put you at an increased risk of developing heart disease, the No. 1 killer in Canada. That’s why experts now believe it’s your waist, not your weight, that matters most. And they’re encouraging doctors to add a lowtech tool to their medical arsenal: the humble measuring tape.

The dangers of having a thick middle are by now wellknown. Not to be confused with the soft flab you can grab with your hands (“subcutaneous fat” in medical lingo), visceral fat—the hard tissue that packs around the waistline, below the muscle layer—has been associated with a host of health problems, from dementia to some types of cancer. An excess of it can also cause a hard, rounded pot belly to form. “We used to think fat tis-

Abdominal obesity is 'the cholesterol of the 21st century,1 says one medical expert

sue was an inert storage vessel,” says endocrinologist Dr. Robert Hegele of the Robarts Research Institute, University of Western Ontario (UWO). “It turns out it’s almost like a gland.” And it might even make you fatter: in March, UWO researchers revealed visceral fat produces neuropeptide Y, an appetiteinducing hormone (whether this hormone actually reaches the brain to cause hunger has yet to be determined).

Heart disease, which afflicts tens of thousands of Canadians every year, has long been linked to three major modifiable risk factors: smoking, hypertension and a diet high in saturated fats. Després thinks another should be added to the list: visceral fat, which he calls ‘the cholesterol of the 21st century.” While the health effects of abdominal obesity are not entirely understood, it seems to contribute to heart disease by promoting insulin resistance (which causes glucose to accumulate in the bloodstream, and also ups the chances of developing diabetes) and releasing inflammatory agents throughout the body, he says. A protruding pot belly could also signify “you have fat stored in the wrong place,” which suggests it could be built up in other areas, including the heart.

As Després points out, one person can be fat and healthy, while another is thinner but unwell. That’s why determining where we store fat is so important: visceral obesity is the type that’s most likely to contribute to cardiovascular disease. Men and post-menopausal women are especially susceptible (why we store fat where we do is an area of ongoing

KATE LUNAU

research). The best way to determine excess visceral fat is with a CAT scan or MRI; but for convenience, cost and ease of use, surely nothing beats a measuring tape.

Today, “there’s no question waist circumference is a better predictor of heart disease than body weight or BMI [body mass index, a calculation involving weight and height],” says Dr. Samuel Klein, an obesity expert at Washington University in St. Louis, Mo. Indeed, a recent U.S. study of44,600 women showed those with big waists had higher death rates from all causes (including heart disease), even if they weren’t overweight. You’d think, then, doctors would start off every physical by checking the patient’s waistline—yet in Canada, “quite frankly there aren’t a lot of doctors [doing it],” says Marco Di Buono, director of research for the Heart and Stroke Foundation (HSF) of Ontario. Why?

For one thing, it remains controversial. Despite years of research, “this is a science

that’s still in its infancy,” Klein says. As of now, no consensus exists on exactly what constitutes a healthy waist—different organizations provide different guidelines. “Using it diagnostically requires having appropriate cut points for what’s abnormal,” Klein says. (The HSF’s guidelines show the “outer limits” of a healthy waist size, which are largely accepted by the medical community, Di Buono says.)

What’s more, a standardized method for measuring girth—whether it’s around the belly button, below the ribs or just above the hips—is also lacking, Klein notes. To further complicate things, experts believe “normal” waist size varies between ethnicities, and many populations have yet to be studied (the HSF’s cut-off for a healthy waist in the general population is 102 cm for men, 88 cm for women; for Chinese and South Asians, the numbers drop to 90 cm for men and 80 cm for women). As doctors are already strapped

HERE’S HOW TO TAKE A PROPER WAIST MEASUREMENT

1. Clear your abdominal area of any clothing, belts or accessories. Stand upright facing a mirror with your feet shoulder-width apart and your stomach relaxed. Wrap the measuring tape around your waist.

2. Use the borders of your hands and index fingers—not your fingertips— to find the uppermost edge of your hip bones by pressing upwards and inwards along your hip bones.

TIP: Many people mistake an easily felt part of the hip bone located toward the front of their body as the top of their hips. This part of the bone is in fact not the top of the hip bones, but by following this spot upward and back toward the sides of your body, you should be able to locate the true top of your hip bones.

3. Using the mirror, align the bottom edge of the measuring tape with the top of the hip bones on both sides of your body.

TIP: Once located, it may help to mark the top of your hip bones with a pen or felt-tip marker in order to aid you in correctly placing the tape.

4. Make sure the tape is parallel to the floor and is not twisted.

5. Relax and take two normal breaths. After the second breath out, tighten the tape around your waist. The tape should fit comfortably snug around the waist without depressing the skin.

TIP: Remember to keep your stomach relaxed at this point.

6. Still breathing normally, take the reading on the tape.

YOU'RE AT INCREASED RISK IF:

MALE: Your waist measures more than 102 cm (40 in.) fôr the general population, and more than 90 cm (35 in.) for Chinese and South Asian populations.

FEMALE: Your waist measures more than 88 cm (35 in.) for the general population, and more than 80 cm (32 in.) for Chinese and South Asian populations.

© REPRODUCED WITH THE PERMISSION OF THE HEART AND STROKE FOUNDATION OF CANADA, 2008. WWW.HEARTANDSTROKE.CA

for time, “until debate in the research community subsides, there won’t be a great uptake [of waist measurement] at the primary care physician level,” Di Buono says.

When a doctor determines a patient’s chance of developing heart disease, he or she will most likely turn to risk factors pinpointed in the ongoing Framingham Heart Study, which began in 1948 with a cohort of 5,209 people in the town of Framingham, Mass. Risk factors identified there (including the classics, like smoking status, blood pressure and diabetes) are “used extensively globally” to determine an individual’s chances of developing cardiovascular disease, Di Buono says. But critics complain the Framingham risk model misses some important ones: waist size and obesity, for example. “Framingham is one of the best risk engines,” says Dr. George Fodor, head of research at the University of Ottawa Heart Institute’s Minto Prevention and Rehabilitation Centre. “But we know its predictive value is far from perfect.”

Fodor has a mini-Framingham study of his own. In the early 1990s, he began collecting data from 791 subjects in Newfoundland, and is following up with them today.

(That province, he notes, has the highest death rate from heart disease in the country.)

Women with big waists had higher death

Much of the information Fodor has collected relates to metabolic syndrome, a group of abnormalities— including abdominal obesity, blood fat disorders and insulin resistance—believed to be present in about 15 per cent of Canadians. Fodor’s work suggests that if metabolic syndrome is itself a risk factor for cardiovascular disease, the Framingham model would have missed almost two-thirds of highrisk men in his Newfoundland group. “If metabolic syndrome adds a substantial improvement [to Framingham],” Fodor says, another “one or two million people in Canada may suddenly be labelled as high risk.” But if the predictive value of waist size has been controversial, metabolic syndrome is even more so. Defined as “a cluster of the most dangerous heart attack risk factors” by the International Diabetes Federation (IDF), no consensus currently exists on how to describe it: the IDF, the American Heart Association and the World Health Organization all provide slightly different definitions. Even so, they almost all include one thing: abdominal obesity, which Hegele, the UWO endo-

rates—even if they weren’t overweight

crinologist, calls “the first step” of metabolic syndrome. According to the IDF, people with the syndrome are twice as likely to die from a heart attack or stroke (and three times more likely to have one) than those without it.

Scientific squabbling aside, it’s clear enough that a fat belly is bad news. For those looking to ward off its ill effects, though, liposuctionwhile it might make you look trimmer—doesn’t seem to be the answer. In a 2004 study, Klein and a team of researchers vacuumed out an average of 20 lb. of fat (four times the amount usually removed) from the abdomens of 15 obese women. Up to 12 weeks after the surgery, they found no change in the women’s risk factors for heart disease and diabetes. Liposuction targets subcutaneous (not visceral) fat, Klein explains—and unlike dieting, which shrinks a patient’s fat cells, the procedure “doesn’t change the size of fat cells that remain.” As always, the best way to get rid of a paunch seems to be the old-fashioned way: diet and exercise. It’s a message we’ve all heard before, but with a twist—weight loss isn’t the end goal. While a few small changes in lifestyle might not show up on the bathroom scale, they can do wonders for a pot belly. Després is conducting an ongoing study of 150 abdominally obese men (some results of which he recently presented in Istanbul) that sees subjects work with a dietician and kinesiologist around their own preferences instead of being told what to eat and do. After one year, while weight loss was negligible for the most part, subjects lost about nine centimetres around the waist and decreased their visceral fat by 30 per cent (observed in a CAT scan), no small feat.

Earlier this year, the Heart and Stroke Foundation distributed one million measuring tapes across the country. The goal was to encourage people whose doctors aren’t checking their waistlines, Di Buono says, to “force the discussion” with them. But the medical community might not need much more pushing. Last year, in the Canadian Medical Association Journal, doctors were urged to check their patients’ girth. Subjects of the ongoing Framingham study now provide waist size, a criteria that could be included in a future model. It seems a consensus is building.

So, step off the scale and grab a measuring tape. A healthy waist, Després says, is “the new vital sign.” M