After the monthly conversations on the theme of oral health challenges through different life stages (re-watch here), a series of two special webinars in November celebrates the three winners of the Sunstar World Perio Research awards that promote research on the interrelationships between oral health and general health. The selection committee is formed by the representatives of leading international dental journals (Journal of Periodontology, Journal of Clinical Periodontology, Journal of Periodontal Research, Journal of Dental Research).
First two winning papers of 2021, both on the link between periodontal and cardiovascular diseases, were explained by their lead authors, Prof. James Beck and Prof. Richard Singer and moderated by Prof. Kenneth Kornman, president of the Selection committee and editor-in-chief of the Journal of Periodontology.
The winning paper: Periodontal disease classifications and incident coronary heart disease in the Atherosclerosis Risk in Communities
Dr. Beck and his team used the new Periodontal Profile Class Stages System definition (PPC stages) – that puts patients into seven subgroups or “buckets” based on specific phenotypes – to elucidate certain associations between periodontal and cardiovascular diseases.
The PPC stages are characterized by being mutually exclusive groups of people who are clinically alike and not like any other groups. The 4 that were already known were given names that would be familiar to most dentists: Health/Incidental Disease (PPC stage I), Mild Disease (PPC stage II), Moderate Disease (PPC stage III), Severe Disease (PPC stage IV).
Specific subtypes of periodontal disease may increase risk for heart disease and influence the prognosis and the treatment needed to deal with it.
In addition, there are three new extra buckets characterized by having more missing teeth than the other four ones: mild tooth loss /extensive high gingival inflammation (PPC stage V), moderate tooth loss/reduced periodontium (PPC stage VI) and severe tooth loss (PPC stage VII). Some of them were associated with coronary heart disease and not others, meaning that it’s not just periodontal disease but subgroups of periodontal disease that are associated with the condition. The paper showed 4 different outcomes of interest: incident coronary heart disease, incident myocardial infarction, incident fatal coronary heart disease, and incident congestive heart failure. Right from the beginning Dr. Beck’s team found that none of the buckets were associated with congestive heart failure and only two really were associated with cardiovascular disease or coronary heart disease. The severe tooth loss sub-group showed elevated risk for both incident coronary heart disease and incident myocardial infarction.
This group on average had only eight teeth left in their mouths but a whole lot of disease in those. It’s obvious that treating this group will improve their oral status, although it is not sure that just dealing with eight teeth will reduce enough oral inflammation to have an effect systemically. Only PPC stage V bucket was significantly associated with fatal coronary heart disease and has in fact been associated with several systemic diseases and biomarkers of inflammation. Gingival inflammation is reversible and can be prevented by good oral hygiene so treatment may have some effect on the incidence of fatal coronary heart disease in this instance.
The severe disease sub-group has high levels of microbial counts of red and orange complex pathogens and high levels of antibodies. The severe tooth loss bucket also has high levels of microorganisms but very low antibodies indicating that these individuals may not make enough antibodies to reduce these organisms. So, the different subgroups have distinct microbial patterns and in the future that may perhaps help in designing treatments.
In addition to incident coronary heart disease, these buckets appear to be related to excess risk for incident stroke, diabetes, peripheral artery disease, cognitive decline, and Alzheimer’s disease. We don’t know whether our treatments are appropriate for all the buckets because these are all different. Having subgroups enables “precision medicine” or “precision dentistry” which is different from “personalized dentistry”. “Personalized dentistry” means that we know periodontal disease in one person isn’t necessarily the same disease that someone else has, as genes and the environment can influence the periodontal health, the symptoms and how well the treatments may work. But “precision dentistry” differs by the fact that our system can’t cope with having a different type of treatment for every individual so the idea is about identifying groups of people who are clinically and biologically similar so that the same treatment will work for the majority in that group. It will be very important to organize for the future as looking at the phenotype of the different subgroups may allow to improve treatment and its response.
Reference: Beck JD, Philips K, Moss K, Sen S, Morelli T, Preisser J, Pankow J. Periodontal disease classifications and incident coronary heart disease in the Atherosclerosis Risk in Communities study. J Periodontol. 2020 Nov;91(11):1409-1418. doi: 10.1002/JPER.19-0723. Epub 2020 Jun 23. PMID: 32449797.
The runner-up paper: Association of periodontal disease and cardiovascular risk: results from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)
Unlike previous national studies, the HCHS/SOL is among the first complex population sampling design that recognizes the cultural heterogeneity that exists in the US Hispanic Latino population. As such, Dr. Singer and his team could examine the association between periodontal disease and cardiovascular disease risk stratified by Hispanic Latino background groups.
In a diverse US Hispanic latino population, moderate and severe periodontitis was associated with a significant risk of cardiovascular disease with marked sexual disparity and heterogeneity by hispanic/latino background.
The outcome measure used to assess cardiovascular disease risk was the Framingham 10-year General Cardiovascular Disease Risk Score (FGRS) which predicts the probability of having one of nine different cardiovascular outcomes over the next 10 years. The greatest cardiovascular disease risks for both men and women occurred between the ages of 60 and 69 and for this age group, Dominican women and men in particular each exhibited the largest Framingham risk score: 15 % and 40% respectively. Given the fact that the analyses were controlled for many of the well-known putative causes of cardiovascular disease, this could be considered an independent risk on top of the pre-existing risk. The smallest risk scores for that same age group occurred for South American women at 6% and Central American men at 23%. Consequently, in this age category, the risk differences between the highest and the lowest risk categories among the Hispanic Latino background groups were a 9% risk difference for women and a 17% risk difference for men.
In South America, there are huge phenotypic and genotypic differences among the various countries and regions, and with that, differences in diet and physical activity patterns exist. All of this contributes to the differences that were found by Dr. Singer’s team in a multifactorial way.
As such, the stratification by background groups revealed new information and raises the question of the cultural differences that lead to such striking differences in long-term risk.
For gender, the overall combined prevalence of moderate and high cardiovascular disease risk among men was 54% which was more than double the risk among women at 26%. When we look at the cardiovascular disease risk by periodontal status, we found that for women and men with moderate periodontal disease the combined prevalence of moderate and high cardiovascular disease risk was 35% and 62% respectively and for those with severe periodontal disease the combined risk was 44% and 85% respectively. So, there’s quite an impact based on the sexual disparity that exists in the prevalence of risk but additionally the prevalence of cardiovascular disease outcomes varied markedly by many of the population characteristics observed in the study as well. For example, for both men and women, the unadjusted prevalence of high cardiovascular disease risk was highest among those that were the oldest, the least educated and with the lowest incomes. Moreover, this high risk was also observed among those who were foreign born, preferred to speak Spanish, had the longest U.S residency, were diabetic and current smokers. So, related to the longest U.S residency, to acculturation, as the participants became more Americanized, their cardiovascular disease risk increased. In another study Dr. Singer did, unrelated to oral health but that looked at occupational exposures and obesity, he also found the relationship with acculturation: those in the U.S for the longest period had the highest risk of developing obesity. These risk factors seem to go hand in hand with the acculturation.
Reference: Singer RH, Stoutenberg M, Feaster DJ, Cai J, Hlaing WM, Metsch LR, Salazar CR, Beaver SM, Finlayson TL, Talavera G, Gellman MD, Schneiderman N. The association of periodontal disease and cardiovascular disease risk: Results from the Hispanic Community Health Study/Study of Latinos. J Periodontol. 2018 Jul;89(7):840-857. doi: 10.1002/JPER.17-0549. Epub 2018 Jul 20. PMID: 29542123; PMCID: PMC6105526.
It is most important to acknowledge that periodontal disease has implications in multiple parts of the body, and that multiple mechanisms are involved. In the end, there is still much to do to interconnect periodontal diseases with various other systemic diseases and unveil those relationships.
If you want to listen to the experts, you can watch the entire webinar here.
Make sure to catch all episodes of the series by subscribing to our YouTube Channel. The next one will be on the link between periodontal pathogens and oral cancer. See you all there!