By Suzanne Leigh, Medical Tribune News Service
New evidence suggests that inflammation can trigger heart
disease and is present even in people who eat a healthy diet and
have good lifestyle habits.
Research also indicates that this inflammation can be controlled
by cholesterol-lowering drugs, according to Dr. Paul M. Ridker,
reporting in Tuesday's issue of Circulation: Journal of the
American Heart Association.
In a study tracking 472 heart-attack patients randomly chosen to
receive either a placebo or cholesterol-lowering medication, Ridker
and his colleagues found that the drug Pravachol (pravastatin)
successfully lowered levels of C-reactive protein (CRP), a chemical
marker for inflammation.
``This drug appears to have an effect beyond lowering the bad
[low-density lipoprotein or LDL] cholesterol,'' said Ridker,
co-director of cardiovascular research at the Brigham and Women's
Hospital in Boston.
Ridker's team found that CRP levels increased among those in the
placebo group even in cases where patients had successfully lowered
their cholesterol with diet and exercise programs. After five years
of treatment, the CRP level of the drug-treated group was 38
percent lower than the placebo group.
An earlier study, also conducted by Ridker, of nearly 40,000
healthy postmenopausal women found that those with the highest
levels of CRP had five times the risk of developing heart disease
than those with lower levels of the protein.
Even among women who were nonsmokers, had healthy cholesterol
levels and no family history of heart disease, high levels of CRP
were found in some cases, Ridker noted in the 1998 study also
published in the journal Circulation.
Commenting on his latest study, Ridker said that highly
sensitive CRP tests are expected to be on the market by the end of
the year. These tests may be used to determine if
cholesterol-lowering drugs could be beneficial in those patients
who do not have any of the standard risk factors for heart disease.
It is not known what causes the inflammation that is believed to
prompt heart disease, but ultimately we may find that ``[heart
disease is] an inflammatory disease in the same way that we
currently consider rheumatoid arthritis to be an inflammatory
disease,'' said Ritker.
An earlier study by different researchers had rejected the idea
that heart disease might be the result of an individual's exposure
to infectious organisms.
A 1998 study led by Dr. Jeffrey L. Anderson, former chief of
cardiology of LDS Hospital in Salt Lake City, found that levels of
CRP were on average more than twice as high in patients with heart
disease than in healthy patients. Among patients who had a heart
attack, the level was approximately four times higher.
``In addition we found a high rate of antibodies to infectious
agents in our patients, but these agents were also highly prevalent
in our [healthy participants]'' said Anderson.
Although these results were insufficient to dismiss the
hypothesis that infections can cause heart disease, said Anderson,
``they do suggest that simply looking at blood tests for exposure
to these organisms won't be very helpful to individual patients.''
