Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study finds direct association between cardiovascular disease and periodontal bacteria

08.02.2005


Researchers report this week that older adults who have higher proportions of four periodontal-disease-causing bacteria inhabiting their mouths also tend to have thicker carotid arteries, a strong predictor of stroke and heart attack. The study, published in the current issue of the journal Circulation, was supported by four agencies of the National Institutes of Health.



According to the authors, these data mark the first report of a direct association between cardiovascular disease and bacteria involved in periodontal disease, inflammation of the gums that affects to varying degrees an estimated 200 million Americans. But the researchers say the findings are not proof that the bacteria cause cardiovascular disease, directly or indirectly.

"What was interesting to us was the specificity of the association," said Moïse Desvarieux, M. D., Ph. D., the study’s lead author and an infectious disease epidemiologist at Columbia University’s Mailman School of Public Health and the University of Minnesota. "These same four bacteria were there, they were always there in the analysis, and the relationship seems to be pretty much, with one exception, limited to them."


Desvarieux stressed that although the new data further illuminate a long-standing scientific issue, they shed little light on the broader public health question related to cardiovascular disease. The 657 people in the study had their oral bacteria and carotid thickness evaluated at the same point in time. So Desvarieux said, "It’s impossible to know which comes first, the periodontal disease or thickening of the carotid artery." The answer to that question is fundamental to establishing causality--in this case, whether chronic inflammation or infection could have led to the atherosclerosis of the carotid arteries.

He and his colleagues noted that the public health information could come soon. "We will re-examine the participants in less than three years, and, at that point, we can better evaluate the progression of the atherosclerosis and, hopefully, begin to establish a time frame underlying the diseases," said Ralph Sacco, M.D., M.S., associate chair of Neurology, professor of Neurology and Epidemiology, and the director of the Stroke and Critical Care Division of Columbia University College of Physicians and Surgeons. He also is an author on the paper.

The idea that oral bacteria shed from chronic gum infections, enter the circulatory system, and possibly contribute to diseases of the heart and other body organs once was widely accepted in medicine. The concept, known as the "focal infection theory," fell out of fashion by the 1940s, then resurfaced four decades later with the publication of new data proposing a link.

Since then, a major sticking point in advancing the research has been simply how to pursue the hypothesis. Lacking the scientific tools to track oral bacteria in the body over several decades to determine if they directly trigger heart disease, most previous studies pursued indirect evidence. These included various measures of oral and cardiovascular health, which researchers then extrapolated to the influence of the oral pathogens. Conspicuously missing from the debate has been a large, well-designed study that in some way directly evaluates the role of the oral pathogens themselves.

To fill this void, the National Institute of Dental and Craniofacial Research launched the Oral Infections and Vascular Disease Epidemiology Study (INVEST), a multi-disciplinary endeavor whose principal investigator is Dr. Desvarieux. The study, which is the source of the paper published this week in Circulation, will monitor the oral and cardiovascular health of a large, racially mixed group of people. All enrollees in the study live in a northern section of Manhattan in New York City and are age 55 or older. Participants are also members of the Northern Manhattan Study (NOMAS), a prospective cohort study supported by NIH’s National Institute of Neurological Disorders and Stroke. Dr. Sacco is principal investigator of the companion NOMAS study.

"Although more than 600 bacteria have been shown to colonize the mouth, each person tends to carry different proportions of these microbes," said Panos N. Papapanou, D.D.S, Ph.D., an author on the paper and professor and chair of the Section of Oral and Diagnostics Sciences and director of the Division of Periodontics at Columbia University School of Dental and Oral Surgery. He noted that only a subset of bacteria tend to be dominant in dental plaque.

"We wanted to know during the baseline examination of the participants whether it was true that the greater the proportion of so-called ’bad’ bacteria in the mouth, the higher the likelihood of a thickened carotid artery," added Papapanou, whose laboratory performed the periodontal microbiological analysis.

To get their answer, Desvarieux and colleagues collected on average seven dental plaque samples from a total of 657 older adults enrolled in INVEST who had not lost their teeth. The samples, taken from predetermined sites in the mouth, both diseased and healthy, were measured for 11 oral bacteria, including four bacteria widely regarded to be involved in causing periodontal disease: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. The other seven bacteria served as controls, as their role in periodontal disease was either neutral or has not yet been established.

Then, to evaluate their cardiovascular health, the participants received a carotid intima-media thickness (IMT) measurement and provided a blood sample to determine their C-reactive protein levels. C-reactive protein has been reported to be elevated in people with periodontal disease, and recent studies found that testing for this protein may be predictive of developing heart disease.

Controlling for several risk factors that might skew their data - such as smoking and diabetes, both of which are independently associated with these conditions - the scientists found the higher the levels of these periodontal-disease-causing bacteria, the more likely people were to have thicker carotid arteries. Interestingly, they noted no association between IMT, the periodontal pathogens, and C-reactive protein levels, suggesting the protein is involved in another cardiovascular disease pathway.

Next, the scientists wondered whether the broad association might be due to the four pathogens involved in causing periodontal disease, which combined accounted for only 23 percent of the bacteria in dental plaque. If so, the finding would provide added specificity to strengthen the case for the association.

"After re-analyzing the data, we found, with the exception of an oral bacterium called Micromonas micros, the relationship was limited to these four established oral pathogens," said David Jacobs, Ph. D., another author and a professor in the Division of Epidemiology at the University of Minnesota School of Public Health.

"In other words, it was exactly what we hypothesized," said Desvarieux.

However, he cautioned, "It now becomes crucial to follow the participants over time and see whether these baseline findings hold up and further translate into clinical disease."

Bob Kuska | EurekAlert!
Further information:
http://www.nidcr.nih.gov

More articles from Studies and Analyses:

nachricht Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland

nachricht Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>