BackgroundA link between rheumatoid arthritis (RA) and periodontitis (PD) has been established. However, their causal relationship remains unclear and the effect of different serotypes of RA on the PD development has not been investigated. This study aims to elucidate the causal association between PD and different serotypes of RA using Mendelian Randomization (MR).
MethodsA bidirectional two-sample MR analysis was performed using available large-scale genome-wide association studies statistics. The inverse-variance weighted (IVW) or multiplicative random-effects IVW was used to determine causality, depending on the heterogeneity of instrumental variables. Additional sensitivity analyses were also performed.
ResultsThe forward MR analysis identi ed that seropositive RA [odds ratio (OR):1.26, 95% con dence interval (CI): 1.07-1.44, p = 0.0018], but not seronegative RA [OR:1.01, 95% CI: 0.95-1.06, p = 0.9098], was associated with an increased risk of PD. The reverse MR analysis did not show any signi cant causal effect of PD on RA, independent of the serotypes. The sensitivity tests (p > 0.05) con rmed the robustness and accuracy of these ndings.
ConclusionThis study revealed that there was a genetic causal effect of seropositive RA on PD, suggesting that this subtype of RA patients may require speci c clinical attention to prevent the development of PD.
What is already known on this topicPrevious epidemiological studies have suggested a link between rheumatoid arthritis (RA) and periodontitis (PD). However, the causal relationship between PD and different serotypes of RA remains unclear.What this study adds -The application of bidirectional two-sample Mendelian Randomization (bi-TSMR) analysis identi ed that seropositive RA, but not seronegative RA, was associated with an increased risk of PD.How this study might affect research, practice or policy -Clinicians should be aware of the importance of periodontal health in RA patients and consider recommending RA patients to undergo periodontal examination or treatment.