Association between metabolic syndrome and oral pre-malignancy: a community- and population-based study (KCIS No. 28)

To elucidate the effect of metabolic syndrome (MetS) on oral pre-malignancy (OPM) and also to examine whether the effect is independent of areca nut chewing. We enrolled a total of 79,940 subjects aged 20 years or older undergoing both oral mucous examination and health check-up for MetS within the Keelung Community-based Integrated Screening program between 2003 and 2008. We identified 368 leukoplakia, 72 erythroleukoplakia, and 69 oral submucous fibrosis. The multi-variable logistic regression was used to assess the association between MetS and OPM with adjustment of age, gender, areca nut chewing, smoking, and alcohol drinking. Subjects with MetS were at increased risk for OPM (adjusted odds ratio (aOR)=1.68, 95% confidence interval (CI): 1.39-2.04) compared with those without MetS after taking all explanatory factors into account. Among the five components of MetS, subjects with hypertriglyceride (aOR=1.43, 95% CI: 1.17-1.75) and hyperglycemia (aOR=1.30, 95% CI: 1.02-1.67) had higher risk of presenting OPM compared with those within normal ranges. The association between MetS and OPM still persisted even in non-chewers (aOR=1.85, 95% CI: 1.42-2.40) while other risk factors were controlled. We demonstrate a positive association between MetS and OPM, which is independent of areca nut chewing and other confounding factors. This finding provides an insight into a new direction of preventing OPM in contrast to conventional viewpoint focusing on the most important factor of area nut chewing.