Association Between Ra Disease Activity And Tooth Loss: Results Of Two National Cohorts

Background: Cross-sectional studies suggest an association between the presence of tooth loss and/or periodontitis, cytokine levels and disease activity in patients with rheumatoid arthritis (RA) (1). Objectives: To analyze the association between tooth loss and disease activity/inflammatory activity in patients with early arthritis and established RA. Methods: Two data sources were used for analysis. Participants of the early arthritis cohort study CAPEA, conducted between 2010 and 2013, reported their number of teeth present at baseline and were followed over 2 years. Tooth loss categories were defined according to the number of teeth present, as follows: 0, 1-19, 19-27, and all 28 teeth. Disease activity/inflammatory activity data, such as disease activity scores (DAS28-ESR) and disease activity parameters, including swollen joint count (SJC) and inflammatory markers, i.e. erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), were collected longitudinally at baseline, 3, 6, 12, 18, and 24 months. We used linear mixed regression models (with negative binomial distribution for SJC) to estimate the association between tooth loss and disease activity scores, SJC and inflammatory markers (ESR, CRP), over time. We also investigated the association between tooth loss and disease activity/inflammatory markers in patients with established RA, using cross-sectional data from the German National database (NDB) collected between 2015 and 2018. All models were adjusted for age, sex, smoking (ever vs. never), rheumatoid factor and education level, defined as years in education. Models with the NDB data were additionally adjusted for disease duration, missing data were imputed using multiple imputation. In all models, number of teeth was entered as a continuous variable. Results: Of a total of 1,124 CAPEA participants included, those with higher tooth loss were older, more often smokers, had a lower level of education, higher inflammatory markers and higher disease activity scores at baseline (Table 1). Inflammatory markers decreased comparably across all categories of tooth loss over time (Figure 1), in particular CRP. Tooth loss was not significantly associated with CRP or SJC alone. Glucocorticoid use was higher among those with more tooth loss, however dose reduction was similar across tooth loss categories. Among 7,179 NDB participants, adjusted disease activity scores and inflammatory markers were higher across tooth loss categories (DAS28 no teeth: 2.7, all teeth: 2.4; ESR no teeth: 23 mm/h, all teeth: 17 mm/h). SJC was not relevantly associated with tooth loss (no teeth: 1.2, all teeth: 1.2). Mean disease duration in the NDB sample was 13 years. Conclusion: While we observed a significant association between tooth loss and disease activity and inflammation markers in both early arthritis and established RA, our longitudinal results suggest that tooth loss has no influence on response to therapy. References: [1]Rodriguez-Lozano B, Gonzalez-Febles J, Garnier-Rodriguez JL, Dadlani S, Bustabad-Reyes S, Sanz M, et al. Association between severity of periodontitis and clinical activity in rheumatoid arthritis patients: a case-control study. Arthritis Res Ther. 2019;21(1):27. Acknowledgements: We thank all participating rheumatologists and patients for their valuable contributions. The CAPEA periodontitis project was funded by the Deutsche Rheuma-Liga Bundesverband e.V. Capea was funded by an unconditional research grant from Pfizer. The National Database of the German Collaborative Arthritis centers has been supported since 2007 by the Association of Regional Cooperative Rheumatology Centres and joint contributions to the Rheumatological Training Academy and the DRFZ by the following members of the Working Group of Corporate Members of the German Society for Rheumatology: AbbVie, Actelion, BMS, GSK, Lilly, Medac, MSD, Novartis, Pfizer, Roche, Sanofi-Aventis and UCB. The researchers have full academic freedom. Disclosure of Interests: None declared.