Nascimento GG, et al. - Using observed and latent variables for metabolic syndrome (MetS) and periodontitis, researchers examined the relationship between MetS and periodontitis in young adults along with outcomes. They used data from the 1982 Pelotas Birth Cohort, Brazil. Using clinical and biochemical analysis, Metabolic syndrome at the age of 23 years was measured and made the primary exposure, and clinically measured periodontitis at the age of 31 years was made the outcome. They recognized two latent periodontal variables ("initial" and "advanced" periodontitis), while one was recognized for for MetS. They found a positive link between metabolic syndrome and "advanced" (but not “initial”) periodontitis. Yet, when MetS and periodontitis were treated as observed variables, no link was seen regardless of the criteria used for classifying periodontitis.