Metabolic Syndrome and Periodontal Disease

Metabolic syndrome is a systemic condition that has components such as obesity, dyslipidemia, hyperglycemia, and hypertension and is associated with an increased risk of cardiovascular disease and type 2 diabetes. Periodontitis is a chronic inflammatory disease characterized by progressive attachment loss that develops as a result of the host response to the dysbiotic plaque microbiome. Periodontal diseases can jeopardize systemic health through various mechanisms as well as be detrimental to oral health. The interlinks of these mechanisms and the pathogenesis of metabolic syndrome cause a bidirectional interaction between the two diseases. This review aimed to evaluate studies focusing on potential interaction mechanisms between periodontal disease and metabolic syndrome and present the clinical implications of these interactions.

Studies dealing with the relationship between metabolic syndrome and components of metabolic syndrome and periodontal disease are available in the literature, and it is reported that the two conditions are generally related. According to literature findings, inflammation is a common pathway in metabolic syndrome and periodontal disease. While both diseases can exacerbate the inflammation and affect the other, it is also seen that the severity of the disease increases by being affected by the increasing chronic inflammation itself. The fact that they have common risk factors other than the intersecting pathways in the two diseases in the host inflammatory response strengthens their relationship but prevents the understanding of causality and the visibility of the initiating factor. Although these common risk factors affect the prevalence studies, the immune mechanisms identified to date and the results of longitudinal studies show that this relationship is bidirectional. Fewer data describing the relationship between metabolic syndrome and periodontal disease, which is significant for systemic disease risk. This is explained by the factors that make the standardization of studies difficult. The use of different disease definitions, the existence of different forms of periodontal disease, the multi-component of metabolic syndrome, and different study plans prevent standardization and reduce the number of studies to be included in compilations and meta-analyses that will reveal essential information on the subject.

It is thought that the data of longitudinal studies, which have a standardized study design and use common diagnostic criteria, can more clearly reveal the relationship between periodontal disease and metabolic syndrome. Thus, the direction of the relationship between the two diseases (bidirectional or unidirectional), cause-effect relationship, dose-response relationship, and treatment approaches can be obtained.