C-reactive protein, or CRP, a marker of inflammation in the body, is unquestionably associated with heart disease. Multiple studies have found that the more CRP in a person’s blood, the greater the likelihood of heart disease. But in a study that appears in Journal of the American Medical Association, researchers analyzing genetic data from more than 100,000 people conclude that their study “argues against” the notion that the protein causes heart disease. CRP is “a biomarker — a marker of disease process — and not a risk factor,” said Dr. James A. de Lemos, an associate professor of medicine at the University of Texas Southwestern Medical Center, who wrote an editorial accompanying the study. Dr. David Altshuler, a professor of genetics and medicine at Harvard Medical School, said the distinction was important.
The real issue is inflammation. CRP goes along with inflammation, and it is inflammation that is likely to be causing heart disease.
The new study, by Dr. Paul Elliott of Imperial College in London and 35 co-authors, made use of a recently developed technique that can get answers quickly about causality. Without it, the only method was what is seen as the gold standard in medicine — large controlled clinical trials in which people are randomly assigned to take a drug, or not, and followed for years. The new method, Mendelian randomization, “is changing the way we think about causality,” Dr. Lauer said. It is a type of study that only recently became feasible as researchers found genetic variants associated with proteins like CRP and developed tools to analyze data from what was, in this case, more than 100,000 people. Different people produce different amounts of CRP, and the amount a person produces is determined by tiny inherited changes in the CRP gene. So in a population, there are people who just happen to produce more CRP throughout their lives and others who just happen to produce less. If CRP causes heart disease, those who make more CRP would have more heart disease. That, however, is not what the study found. “There was no association” between CRP genes and heart disease rates, Dr. Elliott said. People with genes that increased CRP production throughout life had no more heart disease than those with genes resulting in less CRP. The association between CRP and heart disease must be reflecting something else. For example, if CRP levels go up when heart disease begins, because there is inflammation in the arteries, CRP levels would be higher in people with incipient heart disease.
But CRP itself would be playing no role in heart disease risk — it was just marker of inflammation in the arteries. An elevated CRP level indicates increased risk, even if the protein does not cause the risk.
Bonnie - I never consider CRP a direct risk factor. It simply indicates overall inflammation, which IS a major factor in heart disease and many other inflammatory diseases.
The real issue is inflammation. CRP goes along with inflammation, and it is inflammation that is likely to be causing heart disease.
The new study, by Dr. Paul Elliott of Imperial College in London and 35 co-authors, made use of a recently developed technique that can get answers quickly about causality. Without it, the only method was what is seen as the gold standard in medicine — large controlled clinical trials in which people are randomly assigned to take a drug, or not, and followed for years. The new method, Mendelian randomization, “is changing the way we think about causality,” Dr. Lauer said. It is a type of study that only recently became feasible as researchers found genetic variants associated with proteins like CRP and developed tools to analyze data from what was, in this case, more than 100,000 people. Different people produce different amounts of CRP, and the amount a person produces is determined by tiny inherited changes in the CRP gene. So in a population, there are people who just happen to produce more CRP throughout their lives and others who just happen to produce less. If CRP causes heart disease, those who make more CRP would have more heart disease. That, however, is not what the study found. “There was no association” between CRP genes and heart disease rates, Dr. Elliott said. People with genes that increased CRP production throughout life had no more heart disease than those with genes resulting in less CRP. The association between CRP and heart disease must be reflecting something else. For example, if CRP levels go up when heart disease begins, because there is inflammation in the arteries, CRP levels would be higher in people with incipient heart disease.
But CRP itself would be playing no role in heart disease risk — it was just marker of inflammation in the arteries. An elevated CRP level indicates increased risk, even if the protein does not cause the risk.
Bonnie - I never consider CRP a direct risk factor. It simply indicates overall inflammation, which IS a major factor in heart disease and many other inflammatory diseases.
1 comment:
Although many people think of heart disease as a man's problem, women can and do get heart disease. I was in the same misconception regarding the heart disease, but was made aware by a medical checkup campaign. In fact, heart disease is the number one killer of women in the United States. It is also a leading cause of disability among women.
The most common cause of heart disease is narrowing or blockage of the coronary arteries, the blood vessels that supply blood to the heart itself. This is called coronary artery disease and happens slowly over time. It's the major reason people have heart attacks. Prevention is important: two-thirds of women who have a heart attack fail to make a full recovery.
The older a woman gets, the more likely she is to get heart disease. But women of all ages should be concerned about heart disease. All women can take steps to prevent it by practicing healthy lifestyle habits.
Actually, right now I am suffering from a blockage in the coronary artery and was once blocked up to 85%. I got the stent implantation which is a mesh like spring which is used to broaden the artery and hence restoring back the blood flow. You can see further information regarding stent operation from www.heartsite.com/html/stent.html. I got to know everything regarding my stent operation from this site. I was really unaware of such a blockage. I sometimes feel dizzy, restless, lazy , but thought that to be something related to mental ability, and hence never worried about it. Once I got my basic medical checkup at Elite health medical office in Los Angeles. The ECG report went to be something suspicious. So, they advised me to have further advance diagnosis to determine and assure regarding the problem in the heart. After my MRI , CT scan and other such scans it came to me as a shock that I was facing a problem of blockage. It was quite surprising to me, and as I was not aware of anything regarding this, I was really frightened. The doctors explained me every information regarding my health and its treatment, and suggested me to have stent operation. That was some dreadful days of my life, which I faced only because I was careless about my health. It was my luck that I somehow went for a basic checkup at elite health, but every woman out there may not be so lucky.
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