The heart of the matter

When we discuss the link between oral disease and systemic disease, we must look at the science that links the two entities together. Reviewing the types of evidence, and knowing the differences between association and causation in scientific studies, is crucial to understanding the periodontal disease and systemic disease relationship. This is important if we want to explain this in simple terms when we are treating patients with severe periodontal infection. This article will touch upon the newest science between the link between periodontal and cardiovascular disease.

In April, 2012 the American Heart Association (AHA) published a scientific statement in the journal Circulation that offered an extensive literature review of the evidence on the relationship between periodontal disease and cardiovascular disease (CVD).(1) The conclusion was that strong evidence supports an association between the two, but not causation. Soon after, the AHA and the American Dental Association (ADA) published press releases that stated that there may be “no proof” to connect the two diseases, which confused the profession and the public.(2,3) While a cause-and-effect relationship between oral health and heart health has not been proven, research has indicated that the two are associated and that periodontal disease may increase the risk of CVD in some patients.

Why is there confusion? Headlines stated that “Observational studies to date support an association between PD [periodontal disease] and ASVD [atherosclerotic vascular disease] independent of known confounders.” As well, “They do not, however, support a causative relationship.” When we look at the evidence, we must examine the Temporal Relation, the Strength of the Association, the Dose Response, Consistency, Plausibility and Coherence, Specificity, and Consideration of Alternative Explanations.(4) The authors concluded that association studies generate hypotheses that need to be tested, and that perhaps the “final word isn’t in.”(4)

Oral health professionals are in a daily position to educate patients about the relationship between systemic diseases and periodontal disease, and to mitigate confusion caused by the AHA's statement and press releases, which were not incorrect but highlighted specific aspects of the research. A new article sponsored by Colgate does a wonderful job of explaining the types of evidence, association and causations, and evaluation research results. Practical applications are also discussed.(5)

In summary, we do know that there is an association between periodontal disease and atherosclerotic vascular disease. Studies have not proved that periodontal disease is a cause of atherosclerotic vascular disease. As well, it is not confirmed that heart disease or stroke can be prevented, or the clinical course of atherosclerotic vascular disease modified, by therapeutic periodontal interventions.(4) Stay tuned!

References 1. Lockhart PB, Bolger AF, Papapanou PN, et al; on behalf of the American Heart Association Rheumatic Fever, Endocarditis,and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, Council on Epidemiology and Prevention, Council on Peripheral Vascular Disease, and Council on. Periodontal Disease and Atherosclerotic Vascular Disease: Does the Evidence Support an Independent Association?: A Scientific Statement From the American Heart Association. Circulation. 2012. 22; 125: 2520–2544. 2. American Heart Association. No proof that gum disease causes heart disease or stroke. Available at: www.newsroom.heart.org/pr/aha/_prv-no-proof-that-gum-disease-causes-232043.aspx. Accessed September 2, 2012. 3. American Dental Association. AHA statement: no causative link found between periodontal disease and heart disease. Available at: www.ada.org. Accessed September 2, 2012. 4. Niederman R and Weyant R. Editorial: Periodontal Disease, Cardiovascular Disease, the American Heart Association, the American Academy of Periodontology, and the Rooster Syndrome. Evidence-Based Dentistry (2012) 13, 34-36. doi:10.1038/sj.ebd.6400851. 5. Borgnakke WS. A Closer Look at the Evidence. Dimensions of Dental Hygiene. July 2012; 10(7): 11-14.