Posted on 01/11/2005 5:44:54 PM PST by neverdem
When Richard Newton read in a magazine last year that high levels of a protein called CRP were as powerful as high cholesterol in predicting heart disease risk, he went to his doctor to be tested.
Mr. Newton, a 60-year-old retired electrician in Lynnfield, Mass., assumed that his level of CRP (the letters stand for C-reactive protein) would be low, just like his cholesterol level. His overall health was good. He did not take any prescription drugs and had normal blood pressure. And although he smoked, he was not overweight and he exercised every day, playing tennis or spending an hour on an elliptical cross-trainer.
But to Mr. Newton's astonishment, the simple blood test done by his doctor showed that his CRP level was 3.1, higher than normal, meaning that he ran twice as much risk of having a heart attack or dying from heart disease as people whose levels were lower than 1 milligram per liter of blood.
He asked for the test to be repeated, "just to make sure," he said.
In August, he had another CRP test. Once again, the level was 3.1.
"I don't know how you get it down," Mr. Newton said. "I don't know what it means. Are your arteries swollen up or does it make your arteries swell up?" In the meantime, he worries.
Mr. Newton's quandary is becoming more common as scientists become increasingly convinced that CRP and heart disease are linked but do not know exactly what the relationship is. Until recently, it was the doctors who made the decisions about whether and whom to test for CRP. Most patients had never heard of the protein. That has been changing with increasing publicity; after widespread news reports on two studies published in The New England Journal of Medicine last week, some doctors say they are being flooded with requests from people who want a CRP test, now.
Many insurers pay for the test, whose list price at one national testing laboratory, Quest Diagnostics, is $55, according to Gary Samuels, a company spokesman. "Plans that haven't covered it are re-evaluating it in light of the new studies," he said.
Scientists have known for some time that CRP levels can predict the risk of heart attack as powerfully as better-known risk factors like high blood pressure and high cholesterol. The higher the CRP level, the greater the risk. But they still did not know whether reducing the level would reduce the risk.
The new studies addressed that by analyzing what happened when heart patients took statins, the drugs that lower cholesterol. Statins, it turns out, also lower CRP levels, but that effect is independent of their effect on cholesterol. That allowed the investigators to ask: Is lowering CRP independently protecting patients from heart attacks and the worsening of atherosclerosis?
The answer, the researchers found, appeared to be yes. But the studies involved patients with severe heart disease, not healthy people or people at risk for heart disease. Studies are now under way in healthy people, but, in the meantime, cardiologists are divided about whether it is helpful to measure CRP in most patients and what to do when the level is high.
Some cardiologists - including Mr. Newton's, Dr. Christopher Cannon of Brigham and Women's Hospital in Boston - say nearly all patients can benefit from knowing their CRP. If it is high, he said, that can motivate patients to take measures to reduce their risk of heart disease. (Dr. Cannon, an author of one of the new reports on CRP, receives honorariums and research financing from a variety of companies making drugs for heart disease, and he serves on advisory boards for 10 companies.)
The levels of the protein, which is made in the liver and in cells lining blood vessels, rise with things that make heart disease more likely, like smoking, obesity, high cholesterol and diabetes. They fall when patients stop smoking, lose weight and get their cholesterol and diabetes under control.
But the exact role of CRP remains subject to debate. Infectious-disease specialists note that the protein is part of the body's way of fending off microbes. When an infection begins, CRP latches onto microbial invaders, marking them for destruction by white blood cells.
CRP is also released in chronic inflammation. One hypothesis says that in heart disease, a chronic inflammation of coronary arteries, the protein itself directly contributes to rupturing plaque and forming blood clots that block arteries, the components of a heart attack. But some say it remains possible that CRP is an indicator of a risk of heart attacks, not a cause.
Many doctors say they urge patients with high CRP levels to lose weight if they are overweight, or stop smoking if they smoke. They may also use high CRP as the deciding factor in whether to prescribe a statin to patients whose cholesterol levels are borderline high.
Still, it has not been demonstrated that a fall in CRP when someone stops smoking, for example, confers any more protection from heart disease than simply stopping smoking. Some scientists suspect that it does. Others say they await evidence. But many, including Dr. Cannon, say it makes sense to use a high CRP level as a motivating factor to change bad habits.
"When you're faced with a test that shows that you're at increased cardiac risk - and this is your blood, your body - it can resonate," he said.
With his patient Mr. Newton, Dr. Cannon said, "I think it's helping him worry about stopping smoking."
Mr. Newton says he is trying to quit. He now smokes just a few cigarettes a day - down from a pack - and plans to have his CRP tested again in six months. In the meantime, it is a nagging concern. And because the average CRP drop with smoking cessation is 0.5, chances are that even if he stopped smoking entirely, he still would have a level that conferred risk.
Even the motivation argument is debated. One study found that patients who saw an artery scan showing that they had atherosclerosis were more inclined to change their ways. Another found that patients who saw scans of their hearts indicating atherosclerosis did not change their habits in the end, said Dr. Sidney Smith, a heart researcher at the University of North Carolina. "It remains an untested question how patients might be motivated when they see their CRP," he said.
Dr. Smith has participated in research that was sponsored by companies making heart drugs and has spoken at company-sponsored symposiums at medical meetings.
Some researchers, like Dr. Scott Grundy of the University of Texas Southwestern, do not measure CRP in most patients. People who are diabetic or obese, who smoke or who have high levels of cholesterol or high blood pressure should be doing something to address those risk factors anyway, said Dr. Grundy, who has conducted research that was supported by companies making drugs for heart disease and has received honorariums from drug companies.
Dr. Daniel Rader, a heart researcher at the University of Pennsylvania, also does not order CRP tests for most patients.
"The question the doctor always has to ask himself is, 'What am I going to do about the result when I get it back?' " Dr. Rader said. "That's my biggest issue." Dr. Rader receives research support and honorariums from a variety of companies making drugs for heart disease.
Neither Dr. Grundy nor Dr. Rader has had a CRP test himself. Other doctors order the test for all their patients, and have even tested themselves and their families.
Dr. Cannon, for example, tested himself and his wife. His CRP was below 1, he said, and his wife had a level so low it was undetectable. If he had learned that his CRP was elevated, Dr. Cannon said, he would have dieted and gotten more exercise.
Dr. Cannon also got a call from a friend's wife. She told him her husband had just had a CRP test and had gotten bad news: his level was 14. Dr. Cannon suggested working on diet and exercise. The husband, he said, "is overweight, he doesn't exercise enough, they eat terribly." Now, Dr. Cannon said, the man and his wife want to change their ways.
Meanwhile, even Dr. Smith, who is circumspect about wholesale CRP testing, could not resist finding out his own level. It was fine, he says.
And some doctors who have had the test cannot resist bragging if their level is low.
Dr. Cannon said that not long ago he was staying at a hotel for a medical meeting and went to the exercise room at 6 in the morning to work out. There he saw two prominent cardiologists, one on the treadmill and the other on the elliptical cross-trainer. The men were talking, comparing their CRP levels.
"Mine is 0.4," one said.
The other puffed out his chest. "Mine," he declared, "is 0.2."
what a stupid headline
I have the opinion that aspirin in variable doses lowers CRP. Does anyone know if that's right?
booked
whatever happened to the thesis that poor dental health contributed to elevated imflammation levels(CRT) and thus was a risk factor?
ooops - CRP...
CRT is this:
http://64.233.161.104/search?q=cache:BAzGVQfZRT0J:www.keytohealthclinic.com/crt.html+dental+health+CRT&hl=en
Yes, you might think from the wording of the article that consuming protein is linked to increased heart disease.
This could explain the Aleve/Vioxx/Celebrex problems. People with inflammatory diseases such as arthritis and fibromyalgia take Aleve, etc. for pain relief.
Maybe the CRP was the problem, and not the drug.
Also, I read that people who take those drugs should also take aspirin to help their hearts.
Oh great, now we have to go to Canada to get cheap antimicrobials......
/s
aspirin.
wonder drug.
right under our noses all this time.
Aspirin seems to be a wonder of the ages.
Study finds antibiotics do not prevent heart attacks
Results from landmark PROVE IT-TIMI 22 trial suggest clinicians should use proven therapies, such as high-dose statin therapy, to reduce cardiovascular disease risk factors.
Previous studies have found Chlamydia pneumoniae, a common bacterium that causes respiratory illness, may also be a risk factor for atherosclerosis and other cardiovascular diseases. Researchers and clinicians had hoped that treating C. pneumoniae with antibiotics would kill the bacterium and therefore reduce the risk of cardiac events. However, in the landmark PROVE IT-TIMI 22 clinical trial, researches from Brigham and Women’s Hospital (BWH) and colleagues found that even a long-term regimen of antibiotics designed to kill C. pneumoniae does not reduce heart attacks or cardiovascular disease risk. Clinicians instead should continue to focus on other methods to reduce risk factors such as high-dose statins and ACE inhibitors.
Commenting from the European Society of Cardiology meeting, lead investigator of the PROVE IT – TIMI 22 trial (Pravastatin or Atorvastatin Evaluation and Infection Therapy), Christopher P. Cannon, MD of the TIMI Study Group in the Cardiovascular Division of BWH and associate professor of Medicine at Harvard Medical School (HMS) said, "This portion of the PROVE IT-TIMI 22 trial looked at the impact of full-dose, long-term use of antibiotics but found they did not prevent heart attacks. Clinicians need to use proven therapies to treat heart disease risk, including high-dose statins, found to be effective in the statin component of the PROVE IT trial."
PROVE IT enrolled 4,162 patients hospitalized within 10 days for an acute coronary syndrome. Approximately half the patient population was administered the antibiotic Gatifloxacin and the other half was administered a placebo, each for a 10-day course per month over a period of two years. Researchers found that those who participated in the antibiotic therapy had the same risk of a cardiac event as their placebo therapy counterparts.
"While there have been great strides in addressing cardiovascular diseases, a regimen of antibiotics does not appear to be effective in reducing coronary risk," said Eugene Braunwald, MD, chairman of the TIMI Study Group at BWH and HMS professor.
The abstract from the latest article in the NEJM had no mention of the results from the antibiotic arm of the trial.
C-Reactive Protein Levels and Outcomes after Statin Therapy
FReepmail me if you want on or off my health and science ping list.
Wonder how "informed" the consent was in that trial ???
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