New germ theory of disease

This was one of the questions posted on Dr Helen.

There seems to be increasing evidence that many chronic health problems that were considered "lifestyle" problems are in fact infectious diseases, the most famous of which is peptic ulcers and H. pylori. There have been reports of an association between staph and coronary artery disease. What are the current research findings on this?

Let us say that this line of questioning is neither new nor shocking. Paul Ewald has tried to makes this argument in his book “Plague Time”. Derek Lowe has written about this from a drug company standpoint in this post.

However, in cardiology, three observations relating to CAD cast severe doubt on the theory that high cholesterol cause CAD. This theory probably came as the result of the Framingham Cohort study. But it is interesting to note the three observations...

• 30-40 % of patients who suffer a heart attack have normal cholesterol levels.
• That we do not totally know the cause of CAD, but in studies on risk factor profiling, in an attempt to predict disease, the risk factos seem somewhat unrelated to cholesterol only, suggesting the possibility that another common, general condition may be the common factor, linking cholesterol, the X factor and CAD.
• Pathological study of the composition of the cholesterol plaque (atheroma) shows the presence of inflammatory cells, which is often present in response to another infection.
  

Some heart attacks in elderly, seemed to have been triggered by the common "flu" and pneumonia. In fact, the feelings among some cardiologists were so strong that some patients were given antibiotics in an attempt to eradicate infections. These are reputable cardiologists working in the field including luminaries like Italian cardiologist, Dr Atilio Maseri. Dr Maseri tried to culture the atheroma causing bacteria. Some of the organisms implicated included Helicobacter Pylori, chlamydia, pneumonia, the cytomegalic virus, the coxsackie virus and others.

The feelings were so strong that a large scale clinical trial (PROVE-IT, TIMI 18) had one arm that was given an antibiotic to see if it would lessen clinical events. It was negative. Another large study, call "WIZARD ", was also negative. These studies seem to have put the last nail in the coffin of infections as a cause of CAD.

All that time spent was not wasted. Coming out of this work, is an alternative way to explain our first three observations, namely the theory of inflammation. Just to summarise, in the interest of space and your patience, atherosclerosis may after all be an inflammatory disease with cholesterol as an important initiator of this inflammation.

Follow the outstanding work of Dr P.Libby and Dr Paul Ridker, both of Boston and Peter Bringham Hospital. This same inflammatory components also seem to explain our understanding of diabetes mellitus, hypertension and heart failure. Even atrial fibrillation may be an inflammatory disease.

So there is some element of being half correct in that possibly inflammation, not infections per se, could explain many common lifestyle problems.

Possibly we have bored the readers enough but if you wish to know more about CAD as an inflammatory disease, please do leave a comment.

Technorati Tags: Cardiology, Inflamation, Disease