DALLAS (American Heart Association) -- Tooth loss caused by gum disease may be a marker of cardiovascular disease before symptoms appear, researchers report in today's rapid access issue of Stroke: Journal of the American Heart Association.

Preliminary findings from the Oral Infections and Vascular Disease Epidemiology Study (INVEST) suggest a link between tooth loss and subclinical atherosclerosis - the symptomless buildup of artery-clogging plaque in the carotid arteries, the vessels that feed the brain, says lead investigator Moïse Desvarieux, M.D., Ph.D., of the University of Minnesota, Minneapolis.

"To our knowledge, this is the first paper to identify a relationship between tooth loss and subclinical cardiovascular disease," Desvarieux says.

Some studies have suggested a link between gum disease and adverse events, such as heart attack and stroke.

INVEST is a prospective, population-based, multicenter study of the relationship between periodontal disease, tooth loss and subclinical atherosclerosis. The phase of the research reported in this study addresses whether the number of missing teeth correlates with periodontal disease, and with the amount of plaque in neck arteries detected by ultrasound.

In this part of the study, researchers report on the first 711 participants. They plan to enroll 1,050. Participants - blacks, whites and Hispanics, age 55 and older - are being randomly recruited from northern Manhattan. None have a history of heart disease or stroke. The average age of the subjects enrolled to date is 66.

All participants underwent thorough dental, physical and neurological examinations. Their dental hygiene habits were recorded, including the number of times per week they brushed and flossed. Participants underwent ultrasound to detect plaque build-up in the carotid arteries. Researchers recorded socioeconomic characteristics, and cardiovascular risk factors.

The prevalence of carotid plaque increased with the number of missing teeth. Among those missing zero to nine teeth, 45 percent had carotid artery plaque. About 60 percent of those with 10 or more missing teeth had plaque build-up in the vessels.

Researchers speculate that tooth loss is an indicator of chronic infection or inflammation of the gums. Since tooth removal practices vary, researchers caution that not all tooth loss may indicate the same amount of severe gum disease.

Desvarieux notes that many of the study participants with periodontal disease also have other risk factors for cardiovascular disease, such as smoking, poor diet and low levels of physical activity. He notes that tooth loss may be more than a simple marker for lifestyle because the relationship remained after accounting for the role of other risk factors and cultural factors.

As the study continues, progression of atherosclerosis, periodontal disease and tooth loss will be examined. This may begin to shed light on the potential but unproven link between the two diseases, researchers say.

Co-authors are Ryan T. Demmer, M.P.H.; Tatjana Rundek, M.D., Ph.D.; Bernadettte Boden-Albala, DrPH; David R. Jacobs Jr., Ph.D.; Panos N. Papapanou, D.D.S., Ph.D.; and Ralph L. Sacco, M.D., M.S.