Poor Oral Health as a Risk Factor for Dementia in a Swedish Population: A Cohort Study with 40 Years of Follow-Up

Article type: Research Article

Authors: He, Fei^{a; b; 1} | Luo, Huizi^{b; 1} | Yin, Li^b | Roosaar, Ann^c | Axéll, Tony^d | Zhao, Hongwei^e | Ye, Weimin^{a; b; *}

Affiliations: [a] Department of Epidemiology and Health Statistics, Fujian Medical University, Fuzhou, China | [b] Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden | [c] Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden | [d] Maxillofacial Unit, Halland Hospital Halmstad, Halmstad, Sweden | [e] Department of Epidemiology and Biostatistics, Texas A & M University, College Station, TX, USA

Correspondence: [*] Correspondence to: Weimin Ye, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, 17177, Sweden. Tel.: +46 (0)8 524 861 84; E-mail: [email protected].

Note: [1] These authors contributed equally to this work.

Abstract: Background:Whether poor oral health is associated with dementia risk remains unclear. Objective:We conducted a cohort study of 14,439 participants who were followed up for up to 40 years in Uppsala County, central Sweden, aiming to explore the association between poor oral health, namely the number of tooth loss, dental plaque status, and oral mucosal lesions, and the risk of dementia. Methods:We used Cox proportional hazards regression model to derive cause-specific hazard ratios (HR) and corresponding 95% confidence intervals (CI), while adjusting for baseline potential confounders as well as a time-varying covariate, Charlson’s Comorbidity Index score. Results:Dementia risk was substantially higher among those with a higher number of tooth loss; compared to the group with tooth loss 0-10, the HRs were 1.21 (95% CI: 1.02, 1.42), 1.17 (95% CI: 0.97, 1.40), and 1.30 (95% CI: 1.09, 1.54) respectively for groups with increasing number of tooth loss. There was some evidence of dose-risk association in this study, with a HR of 1.10 (1.04, 1.18) comparing adjacent groups (ptrend = 0.001). In a stratified analysis by attained age, tooth loss was more pronouncedly associated with the risk of dementia onset before age 80 (those with 21-32 versus 0-10 lost teeth, HR = 1.82, (95% CI: 1.32, 2.51); HR = 1.22 (95% CI: 1.10, 1.35) comparing adjacent groups, ptrend < 0.001). Conclusion:In summary, there are some indications that poor oral health, as indicated by more tooth loss, is positively associated with an increased risk of dementia, especially for dementia onset before age 80.

Keywords: Cohort study, dementia, oral health

DOI: 10.3233/JAD-215177

Journal: Journal of Alzheimer's Disease, vol. 92, no. 1, pp. 171-181, 2023