Study of proteins rejected role in Heart Disease

Protein, blood, was short by some to be more important here that the cholesterol in heart disease appears to be a little more than a spectator.

The substance, C-reactive protein or CRP, a sign of inflammation in the body, is certainly related to heart disease: the more CRP in the blood of a person, the greater the likelihood of heart disease.

But in a paper published Wednesday in the Journal of the American Medical Association, researchers from the analysis of genetic data of more than 100,000 people think that the study "precludes the idea that the protein causes heart disease.

Dr. David Altshuler, a professor of genetics and medicine at Harvard Medical School, said that the distinction is important. If CRP causes heart disease, reduce the people to protect. But if it is only in the context of the disease, reduction of CRP did not affect the health of more value, a shrieking fire alarm would have on the implementation of a fire.

Many believed, CRP causes heart disease, particularly after a well-known study published last year suggested that people with low cholesterol, but less high levels of CRP heart attack, if a statin, a cholesterol Senker, lowering CRP.

This could mean that the reduction in CRP could prevent heart disease. Of course, it also could be to reduce cholesterol, protective measures, but many researchers have argued that reducing CRP.

"It has a very Vocal riding with the idea that the causes of CRP or contribute to the development of heart disease," said Dr. Daniel Rader, an expert on lipids at the University of Pennsylvania. He noted that some companies try drugs, to lower CRP.

But Dr. Michael S. Lauer, director of the Division for the prevention and epidemiology at the National Heart, Lung and Blood Institute, said he might leave now that Smart research.

"It is likely that the drugs or agents specifically CRP are not working," Dr. Lauer said.

The results do not change the current treatment. CRP and one of the main researchers, Dr. Paul M. Ridker of Brigham and Women's Hospital in Boston, the study director last year, the name of Jupiter, and most researchers in the context of the excitement about the CRP, said the new study did nothing for him.

Dr. Ridker, inventor of a laboratory test for CRP, the benefits of their use, so that the new results do not support a causal link, he did not think it is certainly be excluded.

Nevertheless, he says, it does not matter, because the real question is inflammation. CRP, in collaboration with the inflammation, and it is an inflammation that can cause heart disease, said Dr. Ridker.

The idea is that white blood cells enter the artery walls and chemicals can be harmful to plaque formation.

The new study by Dr. Paul Elliott of Imperial College London and 35 co-authors, who recently developed a technique, answers quickly causation. Without it, the only method, which is the default or in medicine: large clinical trials in which individuals are chosen randomly assigned to a drug or not, and after years.

The new method, Mendelian randomization, "change the way we think of causation," said Lauer. It was recently, because researchers have found genetic variations, with proteins such as CRP and develops tools for analyzing data from the, what was, in this case, more than 100,000 people.

Different people different amounts of CRP, and the height of a person is produced by small changes in the CRP gene inherited. So in a population, there are people who do, for CRP during their lives, and others who just happen to produce less. If CRP causes heart disease, those who have more than heart disease. But this is not what the study showed.

"There was no link between genes and heart disease CRP prices," said Elliott.

The association between CRP and heart disease must be something else. For example, if levels of CRP, if the disease begins to heart, because the inflammation in the arteries, CRP level was higher for those starting heart. But CRP itself plays no role in the heart of risk, it was only a marker of inflammation.

A small study of CRP in the same way and published last October in The New England Journal of Medicine, came to the same result.

But this second major study was necessary, experts from the heart, said Dr. Sekar Kathiresan, head of preventive cardiology at Massachusetts General Hospital.

"This is a very important issue especially in the context of the study of Jupiter," said Dr. Kathiresan.

Mr. Rader, at Penn, said he still had CRP tests in patients and expects to continue. An increase in CRP level showed a higher risk, although the protein does not mean that risk. Mr. Rader-CRP testing to determine whether treatment with statins in patients with normal cholesterol, but with a family of heart disease. A high level of CRP, he said, could be decisive, that he, a statin.

Dr. Altshuler noted that part of the performance of a Mendelian randomization study, they said, could be a premature assumption as a fact.

Normally, science starts with observation, such as the involvement of CRP in heart disease. This generates a hypothesis - that causes cancer CRP. Then, a study, if a treatment like a drug in a targeted attack CRP, that people can be selected at random, to protect themselves or not.

But it may take years or decades before clinical trials are completed. In the meantime, said Dr Altshuler, the hypothesis to be true.

And if the clinical trial of the hypothesis, "some are not willing to question their faith, even if no evidence of causation at the beginning," said Dr. Altshuler