Two new studies show a moderate association between the risk of
heart disease and the presence of H. pylori bacterium in the
stomach. The bacterium has been found to be the cause of 90 percent
of ulcers and can be eradicated with the use of antibiotics.
The researchers, led by Dr. John Danesh, Rhodes Scholar at the
Clinical Trials Service Unit at Oxford University, Oxford, England,
conducted two sets of studies, published in the October 30 issue of
the British Medical Journal (http://www.bmj.com).
The researchers stress that their studies do not prove that H.
pylori causes heart disease. To prove that, long-term clinical
trials are needed.
They first examined 1,123 adults, ages 30 to 49, who were
suspected of having suffered a myocardial infarction (heart
attack), and compared them with a similar group of healthy adults.
The results showed that heart attack was almost twice as common in
people infected with H. pylori than those not infected: 472 (42
percent) heart attack patients tested positive for H. pylori,
compared to 272 (24 percent) healthy patients.
Danesh said the study is significant for two reasons. First, he
explained, the results are more precise than those obtained in
other, similar studies because the study involved a larger number
of participants. Second, he said, the people in the new study were
younger than those in previous studies. (Younger people tend to
have greater associations with other risk factors, including
smoking.) ``It lends more credence to our study,'' said Danesh.
The second study conducted by Danesh compared 510 pairs of
siblings, ages 30 to 79. In each pair, one person had suffered a
heart attack while the brother or sister had not. Each male was
compared to his brother of a similar age, while each woman was
compared to her similarly-aged sister. The researchers found that
of the people who suffered a heart attack, H. pylori was present
about one-third more often than in their sibling.
Danesh said that comparing siblings would elicit results from
which the researchers could make stronger conclusions than if the
study involved people who were unrelated.
The researchers examined the results in which one sibling tested
positive for H. pylori while the other did not. Ninety-one heart
attack patients, whose brother or sister tested negative, tested
positive for H. pylori . Meanwhile, there were 67 heart attack
patients who tested negative for H. pylori, while the brother or
sister tested positive.
``These results are compatible with the more extreme findings in
our study involving younger individuals,'' Danesh said. ``The two
studies offer the highest-quality evidence we have of a correlation
between H. pylori and heart attack.'' He added, however, that the
results fall short of indicating that H. pylori causes heart
attack.
The next step, Danesh said, is to set up clinical trials to
determine if eradicating H. pylori reduces the rate of heart
disease.
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British Medical Journal (1999;310:1157-1161)
(The Medical Tribune Web site is at http://www.medtrib.com)
