What does the Doctor Think this month?

THE BODY MASS INDEX (BMI) I love to keep things simple and I was delighted to read an article from the European Congress on Obesity in the British Medical Journal of May 11th. The BMI was invented by Adolph Quetelet in 1830 for population studies, not for individual evaluation of an individual's fatness or thinness. However, around 1972, it began to be used to assess individuals and the folly has continued ever since. To work out your BMI, take your body mass in kg and divide it by the square of your height in metres. The result is expressed in kg/sq m. If you want to work in pounds and inches, you must apply a conversion factor of 703! OK so far? Fortunately, there are many online calculators you can use. According to your BMI, you are categorised as underweight, normal weight, overweight or obese. However, this sytem takes no account of muscle mass, so folk like me, gymnasts and basket ball players, who are solid muscle with little fat will be categorised as obese. My son-in-law, a fitness fanatic built like a whippet with well-toned muscles, is always angry to be told he is obese when attending his annual insurance medical examination. So, what does the BMJ say? It's simple – use a piece of string! First, stretch the piece of string from the top of your head to the floor (your height), fold the string in half and then put it around your waist. If the string does not reach around the waist, your waist measurement is more than half your height and you are at increased cardiovascular risk, so you should diet and exercise until your waist measurement is less than half your height. The survey described in the article was led by Margaret Ashwell of Oxford Brookes University and looked at 2917 adults from the Health Survey for England. Of this group, 12% (350 people) had been classified as normal by their BMI but they had were found to have a waist to height ratio exceeding 0.5. They looked at these 350 people and found them to have significantly higher cholesterol levels than those with a higher than normal BMI but a waist measurement less than half their height. This survey adds weight to the long-held view of some of us that the waist/height ratio is a better predictor of cardiovascular disease the the BMI. Talking of string: A piece of string walks into a bar and asks for a pint of beer. The barman apologises, saying he is unable to serve a piece of string. Dejected, the piece of string leaves but, then, he has an idea. He ties himself into a loop, messes up the top of his hair and returns to the bar. The barman says “Aren't you that piece of string who was here a minute ago?” “No” replied the string “I'm a frayed knot”. (Those of you struggling with this joke – please say it out loud.) Just to demonstrate how confused the cardiovascular risk issue is, let us look at research part-funded by the British Heart Foundation and presented at the recent British Cardiovascular Surgery Conference by Charalambos Antoniades, associate professor of cardiovascular medicine at the University of Oxford. This study suggests that being obese could actually improve the chances of survival after a heart attack. The researchers had wondered why the survival rate after heart attack was better in obese patients than those with a normal BMI. Although obese people are more likely to have a heart attack, they are also more likely to survive it. They have shown that fat surrounding damaged blood vessels releases chemicals that battle heart disease. Obviously, there is much more work to do but, to quote Prof Jeremy Pearson of the British Heart Foundation, “This high quality research, carried out on people and using human tissue, has provided new perspectives on the role of fat in heart disease and has implications for future treatment” I love medicine – it is never boring and we have no idea what is going to be discovered next!

Five blokes in an Audi Quattro arrived at the ferry checkpoint in Harwich, Essex. Tracey, in her brand new uniform, stops them and tells them "I can't let you on the ferry. It is illegal to have 5 people in a Quattro. Quattro means four. One of you will have to get out and stay behind." "Quattro is just the name of the car," the driver replies disbelievingly. "Look at the papers and the seat belts; this car is designed to carry five persons." "You cannot pull that one on me. This is Tracey you're talking to here," she replies with a smile. Quattro means four. You have five people in your car and you are therefore breaking the law. So I can't let you onto the ferry. It's more than my job's worth to let you all on." The driver is now very cross and replies angrily "I've had enough of you. Call your supervisor over. I want to speak to someone with more intelligence!" "Sorry," responds Tracey, "but Sharon is busy with those two blokes in the Fiat Uno." A man got on the bus with both of his front trouser pockets full of golf balls and sat down next to a young lady. She kept looking at him and his bulging pockets. He noticed her attention and, somewhat embarrassed, he explained "It's golf balls". The lady continued to look at him for a very long time, thinking deeply about what he had said, and after several minutes, not being able to contain her curiosity any longer, she asked, "Does it hurt as much as tennis elbow?"

Best wishes to you all Ian Nisbet