Does periodontal disease contribute to other chronic diseases?

Small studies have implicated periodontal disease with an increased risk of several chronic diseases, and a much larger cohort study now seeks to confirm this connection. Researchers in the United Kingdom reviewed over 15 million patient records from across the country and found that patients with a documented diagnosis of periodontal disease were more likely than those without to have additional chronic diseases, including cardiovascular disease (CVD), autoimmune disease, and mental illnesses.

The researchers reviewed records from general practices across the UK, identified over 64,000 patients with documented periodontal disease (inflammation of the gums and/or teeth ranging in severity from gingivitis to tooth loss), and matched them with 251,000 patients without documented periodontal disease by age, sex, and socioeconomic status. Records were followed for a median of 3.3 years (cases) and 3.5 years (controls):

At study entry, the exposed cohort had an increased likelihood of having a diagnosis of cardiovascular disease (aOR [adjusted odds ratio] 1.43; 95% CI 1.38 to 1.48), cardiometabolic disease (aOR 1.16; 95% CI 1.13 to 1.19), autoimmune disease (aOR 1.33; 95% CI 1.28 to 1.37) and mental ill health (aOR 1.79; 95% CI 1.75 to 1.83) compared with the unexposed group. During the follow-up of individuals without pre-existing outcomes of interest, the exposed group had an increased risk of developing cardiovascular disease (HR 1.18; 95% CI 1.13 to 1.23), cardiometabolic disease (HR 1.07; 95% CI 1.03 to 1.10), autoimmune disease (HR 1.33; 95% CI 1.26 to 1.40) and mental ill health (HR 1.37; 95% CI 1.33 to 1.42) compared with the unexposed group.

This study does have some potential limitations. It makes intuitive sense that persons less able to access preventive dental care may also have other chronic diseases caused or exacerbated by lack of access to medical care; the design of a retrospective cohort study cannot establish causation. Given how under-diagnosed and prevalent periodontal disease is worldwide, it's also possible that a significant portion of the control group had periodontal disease that was simply not noted in their electronic medical record. On the other hand, plausible biologic mechanisms suggest that chronic inflammation from periodontal disease may activate inflammatory cascades elsewhere in the body, the study's researchers used appropriate statistical techniques to mitigate confounding variables as much as possible, and the number of patient cases included is, by far, the largest to date.

No study has definitively demonstrated that treatment of periodontal disease improves outcomes in any of these chronic disease states (though low-quality studies have shown that treatment of periodontal disease may lower A1c values in persons with diabetes). Perhaps this new study's findings will inspire further research. In the meantime, it still  makes sense for family physicians to include assessment and counseling regarding oral health in our practices; at a minimum, treating periodontal disease can improve quality of life for persons regarding its associated mouth pain, difficulty with chewing food, and/or difficulty with enunciation.

Periodontal disease is the most common chronic disease in childhood, and at least 25% of U.S. adults over the age of 65 have lost all of their teeth as a consequence of untreated periodontal disease. Let's collectively make a New Year's resolution for 2022 to screen all of our patients for periodontal disease and routinely encourage regular dental care. There's an AFP By Topic on Oral and Dental Conditions, developed in collaboration with the Academy of General Dentistry, with a wealth of resources if you'd like to read more.