November 21, 2002

IDIOTIC THINKING IN MEDICINE 

C-REACTIVE PROTEIN

How The Medical Profession Will Turn A Symptom Into A Disease

By Malcolm Kendrick MbChB, MRCGP (email - malcolm@llp.org.uk )

You may have heard a bit about a substance in the blood called C-reactive protein (CRP). It is released in ‘inflammatory’ conditions in the body: infections, rheumatoid arthritis and also heart attacks. CRP has been around, and known about, for years. However, CRP is about to suffer the same fate of other innocent substances in the blood that have the misfortune to rise in people who have heart disease. It is going to be accused of causing heart disease.

It is a dispiriting fact that, when faced with diseases of unknown cause, the medical profession unerringly manages to get cause and effect completely the wrong way round. In the world of heart disease this has happened with blood pressure, LDL, visceral obesity, insulin resistance and HDL - to name but five. Now it is going to happen to CRP.

When you find an abnormality of some sort that is associated with a disease, you can make a number of different conjectures:

The abnormality is caused by the disease 
An underlying problem causes both the abnormality and the ‘disease’ 
The disease is caused by the abnormality 
It’s a coincidence (one in twenty chance) 
You haven’t measured things properly 
You would think it wouldn’t be that difficult to sort things out, but if you get things the wrong way round to start with, it can takes years, decades - forever? Take high blood pressure. In some cases there is a clear underlying cause e.g. renal artery stenosis. But in the vast majority of cases there is no (clearly) definable cause. 

At this point, rather than say ‘you have high blood pressure of unknown cause,’ the medical profession decided to use a bit of jargon, and so the term ‘essential hypertension’ was born. It means exactly the same thing, but it sounds more scientific and impressive.

Twas but a small step from here to suggest that essential hypertension wasn’t just a sign of some underlying abnormality; it was, in fact, a disease. A disease that needed to be treated. And because essential hypertension was found to be associated with heart disease, it was further decided that if you ‘treat’ hypertension, then you would ‘cure’ heart disease. 

Despite this, many of you probably still think that treating essential hypertension does reduce the risk of heart disease. But, of course, it doesn’t. A fact so carefully hidden behind all sorts of barriers that it can take months to work it out. Finally, you realise that when you read ‘reduction in CV events’ this doesn’t mean reduced rate of death from Coronary Heart Disease (CHD). It primarily means reduced rate of death from stroke.

Hey guys, I can see how a high blood pressure might burst the arteries in your brain. But I can’t see how high blood pressure causes the build up of plaques in the arteries. On the other hand I can see how narrowing an artery with a plaque might reduce blood flow, and trigger a response by the body to raise the blood pressure to keep the blood flow up. Cause that’s simple fluid dynamics. In short, CHD (or atherosclerotic plaques) causes a high blood pressure - AND NOT THE OTHER WAY ROUND.

The example of high blood pressure serves as a lesson in how to turn an ‘associated symptom’ into a disease, and how to get cause and effect hopelessly mixed up. With CRP, we are going to see exactly the same thing. History is in the making, right now, in front of your very eyes.

As a raised CRP is now a recognised risk factor for heart disease, t’will be a very small step to suggest that by lowering it, you will prevent heart disease. I can already see the CRP lowering agents being lined up by the pharmaceutical companies. Watch for the buzz words IL-6 and hyper(c)-proteinaemia. You read it here first.

A word of warning. Whisper it quietly ‘c-reactive protein reducing agents won’t work.’