Trisha E. O`Hehir, RDH, BS
Men with a high level of bone loss associated with periodontal disease are two to three times more likely to suffer cardiovascular problems, including stroke, angina and fatal heart attacks. Three years ago, we discussed this link and the research up to that point.
This link identifies periodontal disease as a risk factor for cardiovascular disease. The 1994 research also suggested that systemic bacteremia, resulting from periodontitis, produced changes in the circulatory system due to endotoxins. At the time, this theory provided a biological rationale, but the findings were not confirmed. Recent reports suggest several explanations, all dealing with the inflammatory process associated with periodontal disease.
In the United States, 50 percent of deaths can be attributed to complications associated with atherosclerosis. Half of these deaths are due to coronary thrombosis and myocardial infarction. From reported studies, it appears that heart disease patients have a number of characteristics in common with periodontal patients. Identified risk factors for both diseases include: age, education, gender, finances, tobacco use, alcohol use, hypertension and social isolation.
A known risk factor for coronary heart disease is infection of unknown origin. Twenty research studies detail this connection, including several discussing dental infections. Since periodontitis is a chronic gram-negative infection, a significant biological burden in the form of endotoxins and cytokines within the blood stream may initiate and/or exacerbate conditions leading to cardiovascular problems. These toxins are linked to the accumulation of fatty deposits on blood vessel walls and may trigger embolism formation.
There also may be an underlying genetic trait responsible for unusually severe inflammatory responses. This genetically linked trait can be measured and has been associated with increased secretion of inflammatory mediators. When blood cells are challenged in the lab by lipopolysaccharide (LPS endotoxin), this underlying trait stimulates the release of pro-inflammatory mediators (cytokines) at levels 3 to 10 times greater than normal. The endotoxins and cytokines enter the blood stream from a periodontal lesion and result in heart and blood vessel problems. The periodontal lesion provides a giant reservoir of endotoxin and cytokines.
White blood cells and their associated inflammatory mediators play a critical role in both periodontal disease and advanced atherosclerotic lesions. Picture the unusually severe response to bacterial plaque endotoxin you`ve seen in patients with uncontrolled diabetes or juvenile periodontitis or refractory periodontitis. While other patients may have a similar amount of bacterial plaque, the inflammatory response is much less.
The genetic marker for abnormally high inflammatory response has been genetically mapped in the same area as susceptibility to insulin-dependent diabetes mellitus (IDDM). This close linkage may explain the increased severity of gram-negative infections in some diabetics. Researchers have shown that most IDDM patients possess the genetic trait for abnormally high inflammatory response, despite the presence or absence of periodontal disease. Diabetes is a known risk factor for periodontal disease, but the presence of the genetic trait in IDDM patients may explain both periodontal disease infections and the higher level of cardiovascular problems in this group.
Researchers have been indirectly testing for the presence of this genetic trait by simply measuring gingival crevicular fluid (GCF). GCF is measured by inserting a small paper strip into a periodontal pocket. The fluid absorbed by the paper strip contains a wealth of information. Levels of pro-inflammatory mediators can be measured, revealing not only the periodontal status of the patient, but also the underlying systemic-host response. This Osulcular dip-stick testO may become a routine part of dental hygiene data-gathering in the future.
Recently, researchers in this field received grants from the National Institutes of Health to continue studying the link between periodontal disease and cardiovascular disease. Leaders in this field include Drs. James Beck and Steve Offenbacher of the University of North Carolina, who received a $2.2 million grant. Their work also has included the link between periodontal disease and premature and low birth-weight babies. Dr. Robert Genco of the State University of New York at Buffalo also received $1.3 million to study the heart disease link.
Prevention is the foundation of the dental hygiene profession. These scientific findings demonstrate that prevention also will be the future of our profession. Optimum oral health is desirable not only for the teeth and gums, but also for general health and longevity.
* Beck, J., Garcia, R., Heiss, G., Vokonas, P., Offenbacher, S.: OPeriodontal Disease and Cardiovascular Disease.O J of Periodontology, 67: 1123, 1996.
Trisha E. O`Hehir, RDH, BS, is a senior consulting editor of RDH. She also is editor of Perio Reports, a newsletter for dental professionals that addresses periodontics. Her e-mail address is [email protected].