New evidence regarding periodontitis as a causal risk for cardiovascular disease and all-cause mortality
Posted: August 7, 2016
Can we now say to our patients and healthcare professional colleagues that periodontitis has been shown to be an independent risk factor for cardiovascular disease and that there is a causal link between the two diseases?
Published in AM J Cardiol (May 2016), Relation of Periodontitis to Risk of Cardiovascular and All-Cause Mortality (from a Danish Nationwide Cohort Study) (Hansen GM, et al.), the authors report that “This nationwide investigation of the association between periodontitis and CVD is one of the largest of its kind to date.”
Although the conclusion in the abstract stated “results support that periodontitis may be an independent risk factor for CVD”, the authors reported that several limitations apply to the results from this study. Within the body of the article the authors clarify that “the reported associations are observational and provide no evidence of causality”. Some of the limitations in this study are overviewed below:
What constituted a diagnosis of periodontitis?
The clinical parameters and radiographic findings used to make the diagnosis of periodontitis are not clarified in the study. It was stated that “the periodontitis hospital diagnoses were not limited to severe disease” and that “Most hospital diagnoses of periodontitis were registered by departments of dental, oral and maxillofacial surgery and based on clinical examination and radiological findings.”
The investigators “found that patients with a hospital diagnosis of periodontitis had markedly increased overall co-morbidity at baseline, and smoking, diabetes mellitus, hypertension, and low socioeconomic status, which are important risk factors for both periodontitis and CVD, were more frequent in patients with periodontitis than in the general population.” They further reported that they “were only able to make adjustments for confounding factors for which data were available.”
It was also noted that “the Danish registers do not include data on body weight, and we were therefore not able to adjust for obesity, which is a well-established risk factor for CVD that may even display a bidirectional association with periodontitis. In addition, the Danish population largely consists of Caucasians of Scandinavian descent and studies of the Danish registers can therefore not account for disease patterns that vary in populations of other ethnicities.”
Bottom line: This study adds to our understanding that to date, there is no evidence of causality with respect to the relation of periodontitis to risk of cardiovascular and all-cause mortality. Periodontitis has not yet been shown to be an independent risk factor for cardiovascular disease.
However, although definitive causality and magnitude-of-effect hierarchy have yet to be determined, there is some evidence upon which to base recommendations for periodontal treatment. The old adage from Evidenced-Based Medicine aptly applies to perio-systemic causation studies: “The absence of evidence is not evidence of absence”.
The authors comments regarding the limitations of this study remind us to be attentive to not overstate the facts to-date when we communicate with our patients and healthcare professional colleagues. Yet we can take advantage of the evidence to-date and better communicate about the importance of treating chronic periodontitis.
With respect to the relation of periodontitis to risk of cardiovascular and all-cause mortality, an example follows of what we can say based on current evidence: “Although periodontitis has not yet been shown to be an independent risk factor for cardiovascular disease, our present understanding is that it may be one. As such, reasonable efforts to decrease inflammatory burdens on the host, such as that caused by clinically relevant chronic periodontitis, should contribute to overall health improvement.”
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George K. Merijohn, DDS
San Francisco periodontist George K. Merijohn practiced 28 years and is associate professor in postdoctoral periodontics at UC San Francisco and U Washington. He is appointed special expert to the California Dental Board; serves as a consultant to dental schools, clinicians, and the legal profession; and is on the editorial board of the Journal of Evidence-Based Dental Practice. Dr. Merijohn leads seminars and workshops at major dental conferences and is published in peer-reviewed journals with articles on mucogingival clinical decision-making, risk assessment, and the evidence-based approach. More about George >