July 19, 2006

Common bacteria linked to circulatory disease

By David Douglas

NEW YORK (Reuters Health) - Infection by Helicobacter
pylori, a bacteria associated with peptic ulcers and gastric
cancer, also appears to increase the risk of diseases of the
circulation, also referred to as "vascular disease," according
to an analysis by Italian researchers.

Lead investigator Dr. Vincenzo Pasceri told Reuters Health
that "clinical studies on the association between H. pylori and
vascular diseases have produced conflicting results. While some
studies have shown a significant association, these results
have not been confirmed in others.

In the June issue of the American Heart Journal, Pasceri of
San Filippo Neri Hospital, Rome, and colleagues report on their
review of 17 studies that looked at the role of
cytotoxin-associated gene A (CagA)-positive strains of H.
pylori in patients with vascular disease of the heart and
brain. More than 6,000 patients were included.

Overall, 13 studies found a statistically significant
relationship between positive strains of CagA and heart
disease. However, this relationship was not seen in
CagA-negative strains. In 4 other studies, there was a
significant association between brain disease and CagA-positive
strains of H. pylori and, again, no association with negative

Infection with CagA-positive H. pylori strains is
associated with a modest but significant risk of vascular heart
disease, continued Dr. Pasceri.

"Even a modest increase in cardiovascular risk may have
great clinical importance," he concluded, "since chronic
infection by virulent strains of H. pylori may be present in 20
percent to 40 percent of the population in Western countries."

Am Heart J 2006;151:1215-1222.