UB Researchers Identify Specific Oral Bacteria Most Likely to Increase Risk of Heart Attack

By Lois Baker

Release Date: March 12, 1999

VANCOUVER, British Columbia -- Oral biologists from the University at Buffalo School of Dental Medicine, among the first researchers to report a relationship between gum disease and risk of heart attack, now have identified the specific types of bacteria that are most damaging to the cardiovascular system.

If the findings are confirmed, it may be possible to target the bacteria with antibiotics or vaccines and lower the risk of heart attack in persons with periodontal disease, according to Robert J. Genco, D.D.S., Ph.D., chief investigator on this and earlier studies on the connection between oral bacteria and heart disease.

The findings are consistent with the hypothesis that specific periodontal pathogens are implicated in the development of cardiovascular disease, added Genco, SUNY Distinguished Professor and chair of the UB Department of Oral Biology.

Results of the research will be presented by Genco here tomorrow (March 13, 1999) at the combined meeting of the American Association of Dental Research and the International Association of Dental Research.

Oral bacteria enter the bloodstream via small ulcers that develop in the gum tissue of persons with periodontal disease. They are thought to increase the risk of heart attack by: 1) contributing to plaque formation, which narrows blood vessels and increases the chance of clots forming, 2) accumulating around damaged tissue, such as a lesion in the blood vessel or a replaced heart valve, which also can narrow blood vessels and cause clots, and 3) inducing platelets to aggregate, which increases the chances of clots forming.

"We've known for some time that oral bacteria can precipitate these kinds of reactions," Genco said. "We now know that these reactions help explain how bacteria that cause gum disease can also increase the risk for heart disease."

Seeking to identify the specific oral bacteria that are most responsible for contributing to heart problems, Genco headed a case-control study of 97 heart-attack patients and 233 controls, who were tested for the presence of eight types of oral bacteria.

Results showed that the heart-attack patients were heavily infected with all bacteria types, but that the risk of heart attack was related significantly only to three types: B. forsythus, P. gingivalis and C. recta., organsims thought to cause periodontal disease in adults. (Not all oral bacteria cause periodontal disease.)

Depending on the bacterial concentration, the increased risk of heart attack in persons with one or another of these bacteria ranged from 200-300 percent, compared to people with no evidence of the bacteria, Genco said.

In a separate but related study, UB dental researchers analyzed records of a random sample of 225 men treated as outpatients at the Veteran's Affairs Medical Center in Buffalo, N.Y., to assess the association between their dental and cardiovascular health. Dental records were compared with diagnoses of coronary-artery disease, congestive heart failure, angina, atrial fibrillation, myocardial infarction or mitral-valve prolapse in both groups.

Results showed that patients with moderate or advanced periodontal disease had a greater prevalence of cardiovascular disease than patients with no periodontal disease, gingivitis or early periodontitis. The study adds more evidence for a connection between oral health and systemic disease.

The periodontal bacteria study was supported by grants from the U.S. Public Health Service. Additional UB researchers were Tiejian Wu, Ph.D.; Karen Faulkner, Ph.D., and Maurizio Trevisan, M.D., from the Department of Social and Preventive Medicine, School of Medicine and Biomedical Sciences; and Sara Grossi, D.D.S., and Joseph J. Zambon, D.D.S., Ph.D., from the Department of Oral Biology, School of Dental Medicine.

The outpatient study was conducted by Guy DiTursi, D.D.S., UB clinical instructor of oral diagnostic sciences; James Katancik, D.D.S., former UB graduate student, and Sebastian Ciancio, D.D.S., professor and chair of the UB Department of Periodontology.