Monday, July 23, 2007

What a waist

I am an enthusiastic subscriber to evidence-based medicine alerts. Basically, I receive content alerts for all of the top medical journals and medical journal collation services that delve through all the crap out there to find the meat and potatoes. I often skim them and delete most of them, but once in a while I come across something that changes my professional practice. I never thought I’d come across something that would change my view on my personal practices.

An article was published in the Archives of Internal Medicine this month titled “Body mass index, waist circumference, and waist-hip ratio on the risk of total and type-specific stroke.” It outlines among other things that abdominal adiposity (spare-tire) is associated with an increased risk of total and ischemic stroke in men. Also, body mass index (BMI) was a risk factor for total and ischemic strokes in both men and women.

Is this an isolated study? No. It was massive. It followed roughly 50 000 people over 20 years to determine whether morphological features would correlate with stroke occurrence. It showed quite convincingly that being fat puts one at an increased risk of having a stroke, especially if that fat is concentrated around the midsection.

I may not look it to most people, but I have struggled with weight all my life. At my apex I was 222 lbs. That was in grade 11. Later that year I hit my nadir at 155 lbs, an unsustainable weight. As the years passed, I slowly crept back into the danger zone. I am now 195 lbs.

The real kicker is that most people tell me (at least to my face) that I do not look “fat” to them. Well, strokes can’t see people. They don’t care if I look fat, just if I AM fat. And according to all accurate clinical measures, I am.

The article mentioned above uses certain ranges as reference groups, basically, the group of people they label as having a risk of 1. Anyone outside of that has risks of 1.2, 1.5, etc. based on how far away from the reference values they fall. The reference values are as follows:

BMI: 18.5-24.9

Waist circumference: <86cm

Waist-to-Hip Ratio: <0.87

To calculate your BMI, go here. Keep in mind all of this only applies to men. Access the article for more information on specific risk factors for women. Well, in the words of a basketball that just got dunked, I’m hooped.

My BMI is 29.6. Even at the high end of the reference range, that means I need to lose 30lbs. However, this does not worry me as much as the waist circumference measures. My waist circumference is 95cm. That is a full 9 cm, almost 4 inches, out of range. If you had a big rubbery meter stick you could wrap it right around my big belly and barely overlap. Sad.

Why does waist circumference concern me and not BMI? Well, because simply put, BMI is a lousy way of determining whether you are fat or not. The lower end of the range is dangerously close to eating disorder territory. Even the upper range will be very difficult for me to attain. Overall, when it comes to how your body affects your risk of dying prematurely, it is not important whether or not you are fat, but if so, where your fat likes to spend its time. If you are moderately overweight, but all your fat is in your head (as I’ve been told from time to time mine is), you should be okay. But God forbid it migrates to the equator. For if that happens, you better take action.

This is not the only article that propounds the risks of abdominal adiposity. Welborn & Dhaliwal report in the European Journal of Clinical Nutrition that based on known data, waist-to-hip ratio is the best predictor of all-cause mortality. Kuk et al. report in Obesity that abdominal fat is an independent predictor of all-cause mortality.

If that is not enough to scare the abdominal fat off of you, I don’t know what is. Since it increases all-cause mortality, I am prone to drive more carefully to avoid a fat-induced car crash. And maybe drive-by shooters see those of us with large spare tires as easier targets. I’m not sure, but no matter what, I’m freakin’ out.

So in true Tony style I have produced an Excel sheet and documented my current biometrics and those for which I strive. Hopefully biking to work will help me get there. If not all the way, I’ll have to cast a lousy-cook spell on my wife. Her culinary creations only serve to expand my girth. Wish me luck. I wish you the same if your fat cells share the centrist leanings of mine.

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