Periodontitis is an inflammatory disease of the tooth-supporting tissues which can lead to degradation of the periodontal ligament and resorption of surrounding bone structure, and in severe cases to tooth loss. Estimates among U.S adults suggest that neariy 15-20% exhibit moderate disease while 5-10% exhibit severe disease, with a prevalence above 20% among older adults. Periodontitis is a leading cause of tooth loss among adults and may lead to deleterious nutritional alterations due to decreased masticatory ability. Metabolic Syndrome (MetS) is a cluster of metabolic risk factors associated with an increased risk of cardiovascular disease (CVD), as well as diabetes. Few studies have evaluated how MetS may affect oral health, specifically periodontitis and tooth loss. We will evaluate whether metabolic syndrome influences progression of periodontitis and incidence of tooth loss over time in a closed-panel longitudinal study of men who have been followed for over 40 years. While few studies have evaluated the association between MetS and periodontitis, the evidence available suggests a positive association. However, all of the studies to date have been cross-sectional, hence temporality of the association of MetS with periodontitis remains unclear. Therefore, we propose a retrospective longitudinal study using clinical measures of MetS components and periodontitis in order to evaluate the effect of MetS on progression of periodontitis and incidence of tooth loss among a closed panel cohort of men. This F32 research training plan will make efficient use of an existing longitudinal dataset to address an important research question - are persons who develop MetS at higher risk for periodontal disease and tooth loss. Public Health Relevance: Metabolic Syndrome is a clustering of metabolic risk factors associated with an increased risk of cardiovascular disease and diabetes. Few studies have evaluated how metabolic syndrome may affect oral health, specifically periodontitis and tooth loss. We will evaluate whether metabolic syndrome influences progression of periodontitis and incidence of tooth loss over time in a closed-panel longitudinal study of men.