Thursday, November 13, 2008


I was very intrigue to read in the latest issue of the New England Journal of Medicine of a study done in Europe, which enrolled 360,000 subjects, who had an average age of 51 years, when the study started. They were all measured for their waistline and BMI ( body mass index ), and followed for 10years. During the 10years, there were 14,732 deaths. The sheer size of the study, allow them to conclude that the waistline was a very important predictor of early cardiovascular deaths. A waistline increase of 2 inches, increase cardiovascular deaths by 13-17% over the next 10 years. Some of these big waistline had normal BMIs, suggesting that the waistline was more important than the BMI. It was noted that the hip/waist ratio was also important.
I have always discussed with my patients that the early Chinese cultural preference for a big pot-belly as a sign of prosperity, has done all of us a large disfavour. It is so very difficult to convince my Chinese patients that they have to keep their belly down. I favour a waistline of 34inches. Any 2 inch increase in waistline, increase early CVS death by 17% in males and 13% in females. Waistline is something that is so easy to measure and cost practically nothing, and yet it is such an important measurement. We all know our waistline because we wear our trousers every morning. Of course we are measuring the waistline at the level of the umbilicus, and not below the pot-belly. We all know the size of the trousers that we wear.
As to the reason why? we now know that the belly fat or visceral fat, is not sleeping or useless. It is a very active organ, screting all kinds of hormones and substances that affect metabolism. Of course the easiest link is with the metabolic syndrome. This syndrome of hypertension, low HDL-C, insulin resistance, abdominal obesity and high triglycerides is a cardiac killer.
What is equally important is that we all can do something to positively modify the CVS risk. Diet and exercise remains the most effective way to reduce our waistline and lessen the CVS risk.
The " middle kingdom " produces substances, maybe interleukin-6 ( IL-6 ), or tumour necrosis factor ( TNF ), that suppresses the cardio-protective adiponectin. The bigger the pot-belly, the higher the insulin resistance, the higher the IL-6, the higher the TNF, the lower the adiponectin, and so the higher CVS risk. Well, there is much more to be learn from the kilograms of " inactive fats " . One thing is for sure. The pot-belly fat is not inactive.
Will you diet and exercise, to reduce your pot-belly, and lower your risk of premature CVS death, especially in those about 50-60years of age? That is the lessen from the study in NEJM.

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