Susan, 45, was undoing her jacket so that I could measure her waist circumference. I was startled by how much her stomach seemed to spring out. She had concealed her girth well. Not using my best bedside manner, I blurted out, “What's this?”
Her husband, who was looking on, was amused by my discovery. He answered, “That, doctor? That's her Canadian tire.”
Though both Susan and her husband chuckled at this, I went into medical-counselling mode. It was no laughing matter. Over time, excess abdominal fat can kill.
In fact, doctors are recognizing that a person's waist circumference (WC) is a powerful predictor of long-term health, and are adopting it as a new vital sign. “Waist circumference is a surprisingly important measurement,” says Arya Sharma, professor of medicine and chair for cardiovascular obesity research and management at the University of Alberta. “Measuring a patient's waist circumference should be part of every physical exam.”
This is an important advance in medical thinking. Vital signs are a special group of measurements, long held sacred in the medical world. The usual list includes pulse, blood pressure, temperature and respiration rate – that's been the standard for generations. But knowing your WC – a simple measurement easily done by patients anywhere – seems to be as powerful as more advanced testing.
How can WC be such a strong marker of future health problems? The WC is a multidimensional measure of abdominal fat, which is not just a storage depot but a factory of disease-causing chemicals. Gut fat acts as an independent organ that pours out dozens of chemicals that slowly poison the body. These pathologic secretions promote high blood pressure, clotting, stress, heart attacks, strokes, kidney disease, diabetes and sudden cardiac death. In the United States, doctors are even taking MRI pictures to get exact measurements of abdominal fat – to know precisely how much you've filled up your tank.
It is also important to understand that waist circumference is not the same as your pant size. To assess the WC properly, the tape measure goes around the abdomen just at or below the belly button. That gets at the pot in the gut, and is different from a pant waistline. It's supposed to be measured once you've fully exhaled, so you can't cheat by sucking in your gut.
Perhaps it's better to think of a waist circumference as your “belly circumference.”
I advised Susan that her WC was 39 inches, four inches above the obesity threshold of 35 inches for Caucasian women. (The obesity threshold for Caucasian men is a WC of 40 inches.) Remembering leaner days, she replied, “Are you kidding, doctor? I haven't been like that since I got married. I thought I was just pleasantly plump.”
Patients typically don't think too badly of the fat they are lugging around. They will use euphemisms such as “love handles,” “belly jelly,” “middle-age spread” or “life luggage.” One obese gentleman protested by saying, “It's not that bad, Dr. Q. There's just more of me to love.”
Beyond the recognized WC differences between the sexes, there is an unsettled controversy about differences between races. The American Heart Association published racially specific waist circumference limits – a literal example of racial profiling. For example, a South Asian man is considered to be obese if his WC is more than 35 inches; a Caucasian man, 40 inches; a Chinese man, 33 inches; a Mediterranean man, 37 inches.
This is important information, pointing the way to racially nuanced and personalized medical thinking. But the unresolved question arises; Why can some races get away with being fatter before they're considered at high risk for medical problems?
In any case, annual check-ups will soon be considered incomplete without a proper measurement of WC. People must appreciate that abdominal fat is not merely an inert fashion challenge but a reservoir of slow-release chemicals.
Medical publishers are now making WC a standard part of medical charts and record-keeping. Patients are empowered as they can track an important predictor of future disease without more expensive tests. To encourage patients to pay attention to their waist circumference, I counsel them to “Waist now.”
Shafiq Qaadri is a Toronto family physician.
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