Periodontal Diseases and the Risk of Metabolic Syndrome: An Updated Systematic Review and Meta-Analysis.

Periodontitis and metabolic syndrome (MetS) are two major global health problems that are widely prevalent in the world, although the former is a common infection in developing countries and the latter is a non-infectious but prevalent disease in developed countries. This study aims to provide an updated review on the existence and magnitude of the relationship between periodontal disease and the risk of MetS. We searched the PubMed, Web of Science, ScienceDirect, Chinese National Knowledge Infrastructure, and Wanfang databases for original studies assessing the association between periodontitis and MetS published before August 2019. We calculated the pooled crude and adjusted odds ratios (ORs) together with the 95% confidence intervals (95% CIs) to estimate the strength of this association. Subgroup analysis was performed by considering the diagnostic method or the country where the studies were performed. We identified 43 potentially eligible articles for this systematic review, including 32 cross-sectional studies, eight case-control studies, and three cohort studies. Among them, 39 articles presented enough information to be included in the meta-analysis. The pooled crude and adjusted ORs were 1.99 (95% CI: 1.75-2.25) and 1.46 (95% CI: 1.31-1.61), respectively. Subgroup analysis showed a consistent relation stratified by either the diagnostic method or the country where the studies were performed. The pooled OR was 1.68 (95% CI: 1.41-2.00) for Japan, 1.75 (95% CI: 1.31-2.34) for the USA, 1.81 (95% CI: 1.35-2.42) for Korea, and 2.29 (95% CI: 1.53-3.41) for China. Our results provide compelling evidence for the association between periodontitis and MetS. Patients with periodontal disease are a critical screening population for MetS. We also recommend that people exhibiting components of MetS should receive a periodontal check-up and pay attention to their oral health.