Study links perio pathogens and heart disease

Apr 5, 2009

The presence of two particular periodontal pathogens and an increase in the total number of periodontal bacteria can indicate a risk of heart disease, according to a University at Buffalo study presented Saturday at the International Association for Dental Research (IADR) meeting in Miami.

While many studies have suggested a link between periodontal disease and heart disease, this study looked specifically at the suggested mechanism behind this connection.

"The direct effect of periodontal pathogens on atherosclerotic plaque development has been suggested as a potential mechanism for the observed association between periodontal disease and coronary heart disease," the authors noted. "Few studies have tested this theory."

The researchers' goal was to not only assess the association of periodontal pathogens with risk of myocardial infarction (MI), but to analyze whether an increase in the number of periodontal bacterial species increases that risk.

The study included 386 men and women between the ages of 35 and 69 who had suffered a heart attack, and 840 subjects with no history of heart disease. All subjects were based in western New York.

The researchers collected samples of dental plaque from 12 gum sites. The samples were then analyzed for the presence of six periodontal pathogens: Porphyromonas gingivalis (Pg), Tannerella forsythensis (Tf), Prevotella intermedia (Pi), Campylobacter recta (Cr), Fusobacterium nucleatum (Fn), and Eubacterium saburreum (Es), plus the co-occurrence of these pathogens.

Patients with a history of heart disease had a higher percentage of each of these bacteria, the researchers noted. Only two pathogens -- Tf and Pi -- had a statistically significant association with an increased risk of myocardial infarction.

"The presence of Tf or Pi and an increase in the number of periodontal bacteria were both associated with increased odds of MI," the authors concluded.

This study examined total periodontal pathogenic burden, and while the results are not new, they add weight to the findings of previous related studies, Oelisoa Andriakaja, D.D.S., Ph.D., and Karen Falkner, Ph.D., two of the authors, told DrBicuspid.com.

"Our study is a case-controlled study; we still cannot say for sure that bacterial pathogens cause nonfatal MI," they said. "This causal association can only be proven with prospective study designs, and especially with intervention trials that show a reduction in any coronary heart disease after periodontal therapy, [such as] the use of antibiotics."

Only if these findings are proven will the role of dentists really change, Dr. Andriakaja and Falkner added. "It is too soon to ask dentists to recommend antibiotics, for example, to patients on a regular basis because the association has not yet been definitively proven."

The authors are currently writing up their findings and expect to submit their paper to a medical journal later this month.