Supplementary Material for: Association between self-reported oral health and Parkinson's disease: evidence from UK biobank

Abstract Objectives Oral health problem is prevalent in the elderly population which is also at high risk of Parkinson’s disease (PD). However, the association between self-reported oral health and PD is still unclear. We aimed to explore the association between baseline self-reported oral health (mouth ulcers, painful gums, bleeding gums, loosen teeth, toothache, dentures) and future incidence of PD. Methods Participants were enrolled in the UK biobank from 2006 to 2010 and those without PD at baseline were included in the current study. We used Cox regression analysis to explore the question and adjusted for age, sex, body mass index, smoking, drinking, ethnicity, education, socioeconomic status, and average total household income before tax. Results We included 421180 participants with a mean age of 56.26 years old and 46.5% of them were male. And 2339 participants were diagnosed with PD in the follow-up. Mouth ulcers, loosen teeth, dentures, toothache, and bleeding gums were not related to the risk of PD. Painful gums were related to a higher risk of PD (HR: 1.39, 95%CI: 1.12-1.72, P = 0.003), and similar results were reached after adjusting for gene risk (HR: 1.39, 95%CI: 1.12-1.73, P = 0.003), or source of diagnosis (HR: 1.39, 95%CI: 1.12-1.72, P = 0.002), and time of diagnosis (HR: 1.29, 95%CI: 1.03-1.63, P = 0.02). Conclusions Our study has demonstrated a substantial correlation between painful gums and elevated susceptibility to PD, underscoring the potential advantages of implementing oral health interventions for decreasing the risk of PD.