UB Biologists Find Genetic Link Between Periodontal Disease, Clotting Factor And Heart Disease

BUFFALO, N.Y. -- Oral biologists at the University at Buffalo have found increased levels of the blood-clotting factor fibrinogen in persons with periodontitis, illuminating one pathway for the relationship between poor oral health and heart disease.

The study also established that persons with periodontal disease are more likely to have a rare form of the gene responsible for fibrinogen expression than persons with no periodontal disease.

S.E. Sahingur, Ph.D., a student in the UB School of Dental Medicine, presented the findings last week at the annual meeting of the International Association for Dental Research.

"This study provides another potential link between chronic infections, such as periodontal disease, and atherosclerotic heart disease," said Ernesto De Nardin, Ph.D., associate professor of oral biology and microbiology, and senior author on the study. He also noted that the findings present the possibility of using these measures as a diagnostic tool to identify people at potential risk for heart disease.

Elevated plasma fibrinogen levels are known to be an independent risk factor for cardiovascular disease by increasing the propensity for blood clots. In addition, De Nardin said, there is a relationship between cardiovascular disease and a polymorphism in the gene for fibrinogen.

There also is a relationship between periodontal disease and risk of cardiovascular disease, and some studies have suggested that levels of the clotting factor are elevated in patients with periodontal disease, he noted.

The UB researchers set out to define the possible fibrinogen-periodontal disease-heart disease link by measuring plasma fibrinogen levels in four groups: those with periodontal disease, with heart disease, with both diseases and with neither. Results showed fibrinogen levels to be significantly higher in persons who had periodontal disease but no heart disease, compared to all other groups.

In the second part of the study, 24 participants with periodontal disease and 26 healthy patients were analyzed for the presence of the rare form (H2H2) of the fibrinogen gene. These results showed that 16 percent of the periodontal-disease group had the rare form, compared to none of the healthy participants.

The analysis also found higher levels of fibrinogen in those with the H2H2 gene, and in those with the heterozygous form (H1H2), compared to those with the frequent H1H1 form.

"Elevated fibrinogen levels have been implicated as a risk factor for heart disease," De Nardin said, "and people with the rare form of the fibrinogen gene (H2H2) produce higher levels of fibrinogen than subjects with the more-common gene.

"Since the production of fibrinogen can be stimulated by an infection, people with the rare gene who also have a chronic infection such as periodontal disease may produce higher levels of the clotting factor, thus putting themselves at even higher risk for heart disease."

Additional researchers on the study were Ashu Sharma, Ph.D., assistant professor of oral biology, and Robert J. Genco, D.D.S., Ph.D., SUNY Distinguished Professor and chair of the UB Department of Oral Biology.

The study was supported by a grant from the National Institutes of Health.