Investigating the relationship between the severity of periodontitis and rheumatoid arthritis: a cross-sectional study

Objectives: This paper evaluates the prevalence and severity of periodontitis (PD) in patients with rheumatoid arthritis (RA), focusing on the link between the severity of PD with RA disease activity/disability scores, the influence of RA treatment on PD, and levels of vitamin D.

Methods: A total of 93 RA patients were enrolled in the cross-sectional study and analyzed accordingly as RA-PD (N = 63, 67.8%) and RA-only (N = 30, 32.2%) groups. A number of associations between rheumatological clinical data, i.e., Disease Activity Score (DAS28 CRP), health assessment questionnaires, and PD severity (measured by periodontal outcome parameters) with regard to serum levels of vitamin D were assessed. The outcome variables were compared by parametric and non-parametric tests.

Results: A total of 29% of RA patients were diagnosed with severe PD. The RA-PD group presented a higher mean DAS28 CRP score in moderate-severe PD compared to periodontally healthy-initial stage PD subjects (4.49 ± 1.22 vs. 3.86 ± 1.58, p = 0.033). RA patients treated with biologic disease-modifying antirheumatic drugs (bDMARDs) were less likely to be diagnosed with PD (p = 0.022) and revealed significantly lower PD outcome parameters, i.e., bleeding on probing (%) and bone loss (%) (p < 0.05). Vitamin D concentration was significantly lower in RA-PD group with diagnosed advanced severe PD (IV stage) compared to moderate PD (II stage) (39.61 ± 17.12 vs. 52.07 ± 18.23 nmol/l, p = 0.031).

Conclusions: The study revealed a high prevalence of severe PD in RA patients, being significantly associated with higher RA disease activity and lower vitamin D level in RA-PD group, while bDMARD treatment was related to lower PD outcome parameters. Key Points • Severe PD is prevalent amongst RA patients and is associated with RA disease activity. The higher RA DAS28 CRP score is associated with moderate-severe PD compared to periodontally healthy-initial stage PD in RA patients. • Biologic DMARDs treatment used for RA is linked to lower PD rates and PD outcome parameters. • Significantly lower vitamin D level is found in advanced severe PD compared to moderate PD stage in RA-PD subjects.

Keywords: Disease activity; Periodontitis; Rheumatoid arthritis; Vitamin D.