Association Between Rheumatoid Arthritis Disease Activity and Periodontitis Defined by Tooth Loss: Longitudinal and Cross-Sectional Data From Two Observational Studies

Abstract

Objective: To analyze the effect of tooth loss/periodontitis on disease activity in early and established rheumatoid arthritis (RA).

Methods: Participants of the Course And Prognosis of Early Arthritis (CAPEA) early arthritis cohort reported their number of teeth at baseline. The number of teeth had been validated as a predictor of periodontitis. Clinical end points, including disease activity score (Disease Activity Score in 28 joints using the erythrocyte sedimentation rate [ESR]), swollen joint count (SJC), ESR, and C-reactive protein level were collected at baseline, 3, 6, 12, 18, and 24 months. We used linear mixed regression models to estimate the association between tooth loss and clinical end points over time in early arthritis. For established RA, we analyzed cross-sectional data from the German National Database (NDB). All models accounted for age, sex, smoking, seropositivity, education level, and disease duration (only NDB).

Results: Among 1,124 CAPEA participants with early arthritis, those with higher tooth loss were older, more often male, smokers, and seropositive, and they had higher disease activity and inflammation markers at baseline. Tooth loss was associated with higher disease activity and ESR values over time. Inflammatory markers decreased comparably across tooth loss categories. Glucocorticoid use was higher among those with more tooth loss, whereas dose reduction was similar across tooth loss categories. Among 7,179 NDB participants with longstanding RA, disease activity and inflammation markers but not SJC were significantly higher in patients with more tooth loss.

Conclusion: Although we observed an association between tooth loss and disease activity scores and inflammation markers in early and established RA, longitudinal results suggest that tooth loss does not hamper treatment response.

Figure 1

Flow chart. CAPEA = Course And Prognosis of Early Arthritis; RA = rheumatoid arthritis.

Figure 2

Disease activity and inflammatory markers during 2 year follow‐up, stratified by number of teeth. CAPEA results from linear mixed models for DAS28, ESR, and CRP and from generalized linear models with negative binomial distribution for SJC28 adjusted for age, sex, smoking, RF, ACPA, and education level. Bars show 95% confidence intervals. * = P < 0.05 for the effect of number of teeth at this time point. Number of teeth was entered as a continuous variable in the models. For illustrative purposes, we show the least square means for selected number of teeth at all time points. ACPA = anti‐citrullinated peptide antibodies; CAPEA = Course And Prognosis of Early Arthritis; CRP = C‐reactive protein; DAS28 = disease activity score in 28 joints; ESR = erythrocyte sedimentation rate; RF = rheumatoid factor; SJC28 = swollen joint count for 28 joints.

Figure 3

Glucocorticoid use during 2‐year follow‐up, stratified by number of teeth. CAPEA results from generalized linear mixed model and binomial distribution for the proportion of patients with glucocorticoid therapy and from a linear mixed model adjusted for age, sex, smoking, RF, and education level. Bars show 95% confidence intervals. * = P < 0.05 for the effect of number of teeth at this time point. Number of teeth was entered as a continuous variable in the models. For illustrative purposes, we show the least square means for selected number of teeth at all time points. CAPEA = Course And Prognosis of Early Arthritis; RF = rheumatoid factor.

Figure 4

Association between number of teeth and disease activity and inflammatory markers in established RA. National database predicted values from generalized linear models, adjusted for age, sex, disease duration, RF, ACPA, smoking, and education level. Boxes show 25th percentile, median, and 75th percentile. Whiskers range from minimum to maximum. ACPA = anti‐citrullinated peptide antibodies; CRP = C‐reactive protein; DAS28 = disease activity score of 28 joints; ESR = erythrocyte sedimentation rate; RA = rheumatoid arthritis; RF = rheumatoid factor; SJC28 = swollen joint count for 28 joints.