Genetic and environmental contributions to the association between mood disorder and periodontal disease: A cross-sectional study among female twins in the UK

Abstract

Aim: This study aimed to investigate the factors associated with periodontal traits considering genetic and environmental background in predominantly older female twins.

Methods: This was a cross-sectional study using self-reported questionnaires for periodontal traits in TwinsUK. Age-adjusted and age-stratified multivariate analyses were conducted for all twins. Subsequently, co-twin control analysis within genetically identical twins who were discordant for periodontal traits was performed by controlling for genetic confounders.

Results: Data of twins aged 20-91 were available in 4,143 individuals for self-reported periodontitis and 4,244 for gum bleeding. Age-adjusted model showed increasing risk in the following: smoking, anxiety/stress and depression for both periodontal traits. Within discordant monozygotic (MZ) twins (514 individuals for periodontitis and 754 for gum bleeding), the association of anxiety/stress remained significant for both periodontitis (OR 1.60, CI: 1.02-2.52) and gum bleeding (OR 1.60, CI: 1.06-2.40). A significant relationship for depression remained for periodontitis (OR 1.68, CI: 1.04-2.70), but it was no longer significant for gum bleeding. Age stratification showed that the association of mood disorders with periodontal traits was generally stronger in older group.

Conclusions: Multivariate analysis among discordant MZ female twins found mood disorders were independently associated with periodontal traits, suggesting that genetic/early-life environmental factors may not explain this association.

Keywords: cross-sectional study; mental health; periodontal disease; population-based study; twin study.