ABC | Volume 114, Nº2, February 2020

Original Article Association between Periodontitis, Genetic Polymorphisms and Presence of Coronary Artery Disease in Southern Brazil Luiz Otavio Rocha, 1 Eduarda Rocha, 1 Guilherme de Menezes Succi, 2 Rui Barbosa de Brito Junior 2 Universidade Federal de Santa Maria, 1 Santa Maria, RS – Brazil Faculdade São Leopoldo Mandic, 2 Campinas, SP – Brazil Mailing Address: Luiz Otavio Rocha • Universidade Federal de Santa Maria - Av Roraima, 1000 prédio 48C. Postal Code 97105-900, Santa Maria, RS – Brazil E-mail: luiz.rocha@ufsm.br Manuscript received October 18, 2018, revised manuscript February 26, 2019, accepted April 10, 2019 DOI: https://doi.org/10.36660/abc.20180296 Abstract Background: Periodontitis and coronary artery disease (CAD) share an inflammatory etiology; there is a recent concern regarding the investigation of an association between these two conditions. Current theories indicate that cytokines and proteins have an important role in this process. C-reactive protein and interleukin-6 are inflammatory derivatives produced in the presence of periodontitis and in the pathophysiology of coronary disease. The polymorphisms of CRP + 1444 C > T and IL6-174 G > C are recognized in the literature as being related to CAD. Objective: This study investigates the association between periodontitis and coronary artery disease, through the presence of PCR and IL-6 polymorphisms. Methods: We selected 80 patients who underwent diagnostic catheterization in the HU of UFSM. The presence of periodontitis was determined by the Community Periodontal Index, whereas the CAD was established by the medical report. DNA was collected from a saliva sample and the presence of polymorphism was determined by PCR and restriction enzymes. A significance level of 5% was adopted. Results: The mean age of all participants (p = 0.035, OR 2.65; 95%CI: (1.02-6.87) male gender (p = 0.012, OR 3.37; 95% CI: (1.28- (p = 0.013, OR 3.66; 95% CI: (1.27-10.5)), PCR polymorphism + 1444C > T (p = 0.001, OR 6.37; 95% CI:, (2.25-17.9)) and IL6 -174 G > C polymorphism (p = 0.025, OR 2.87, 95% CI: (1.09-7.55)) were statistically associated with the presence of CAD. Age > 60 years and presence of the PCR +1444 C > T polymorphism remained independently associated with CAD after adjustment by logistic regression. Conclusions: The presence of the PCR + 1444 C > T polymorphism in this study was independently associated with the presence of coronary artery disease. (Arq Bras Cardiol. 2020; 114(2):268-272) Keywords: Periodontitis; Polymorphism, Genetic; Coronary Artery Disease; C-reactive Protein; Epidemiology. Introduction Periodontitis is a chronic inflammatory disease, induced by biofilm consisting of gram-negative bacteria, leading to the destruction of the tissues supporting the tooth, 1-3 with high prevalence worldwide. 4 The presence of periodontitis triggers the immune system, locally and at distant sites, high concentrations of cytokines and proinflammatory proteins, as well as bacteremia and endotoxemia caused by the bacteria that populate the disease site. 5 Coronary artery disease (CAD) is a chronic, complex, multifactorial, continuous inflammatory condition that consists in the accumulation of atheromatous plaques in the intima layer of the coronary arteries, 6-9 being responsible for acute coronary syndromes, themain cause of death in theWestern hemisphere. 6,7 Inflammation plays a very important role in both periodontitis and CAD. In order to associate these two conditions, two biologically plausible theories were developed, focusing on the direct and indirect action of the oral bacteria present in periodontitis with the inflammatory and pro- atherogenic mediators. 1,2,4,10-14 Based on the inflammatory and immunological theories, several studies have been conducted aiming to establish this association through the genetic factor, the presence of polymorphisms in the genes that express the production of these factors and are associated to periodontitis, such as C-Reactive Protein (CRP) and interleukin-6 (IL-6). 15-19 The simple nucleotide polymorphism (SNP) of the IL-6 promoter gene may affect the production and expression of this cytokine; consequently, this change in serum levels may result in a relevant biological response. 18 The association between the SNP variant -174 G > C (rs1800795) and the increased risk of inflammatory diseases such as CAD has been previously demonstrated. 17,20 Studies point to the SNP rs1136804, also represented as 3 ‘UTR +1444 C > T, as the polymorphism with greater associations with CAD. 15,17 The high prevalence of periodontitis, as well as the high risk of mortality from CAD and a scarcity of studies in this area led to the study of the association between periodontitis and coronary artery disease, by assessing the presence of PCR and IL-6 polymorphisms. 268