Association between Sjögren's Syndrome and Periodontitis: Epidemiological, Fundamental and Clinical Data: A Systematic Review

Immune-mediated inflammatory diseases and periodontal disease: a bidirectional two-sample mendelian randomization study

BACKGROUND

Previous observational studies have shown a bidirectional association between immune-mediated inflammatory disorders (IMID) and periodontal disease. However, evidence regarding the causal role of IMID and periodontal disease is still lacking. Therefore, we conducted a bidirectional two-sample Mendelian randomization (MR) study to uncover the potential genetic causal effects between IMID and periodontal disease.

METHODS

Bidirectional two-sample MR analysis was employed. Data for ten IMIDs were sourced from genome-wide association studies (GWAS) conducted by the FinnGen Consortium (range from 1023 to 36321 cases) and UK Biobank (UKB) (range from 150 to 17574 cases). Furthermore, GWAS data for periodontal disease were obtained from the FinnGen Consortium (87497 cases), UKB (458 cases), and Gene Lifestyle Interactions in Dental Endpoints (GLIDE) consortium (17,353 periodontitis cases). Subsequently, the causal relationships were analyzed by random effects inverse variance weighting, weighted median, and MR-Egger. Sensitivity analyses were performed using the Cochrane Q test, funnel plot, and Mr-Egger intercept test to ensure robustness. Eventually, replication analysis and meta-analysis across different databases were carried out.

RESULTS

Systemic lupus erythematosus (SLE) [IVW: OR = 1.079 (95% CI: 1.032-1.128) and P < 0.001], Sjogren syndrome [IVW: OR = 1.082 (95% CI: 1.012-1.157) and P = 0.022] and hypothyroidism [IVW: OR = 1.52 (95% CI: 1.13-2.04) and P = 0.005] may increase the risk of periodontal disease. In addition, periodontal disease may reduce the risk of SLE [IVW: OR = 0.8079 (95% CI: 0.6764-0.9650) and P = 0.019] and hyperthyroidism [IVW: OR = 5.59*10-9 (95% CI: 1.43*10-15-2.18*10-2) and P = 0.014]. Meta-analysis indicated a causal correlation between SLE and an increased risk of periodontal disease: [OR = 1.08 (95% CI: 1.03-1.13), P = 0.0009]. No significant evidence suggests bilateral causal relationships between other IMIDs and periodontal disease. No significant estimation of heterogeneity or pleiotropy is detected.

CONCLUSIONS

Our study has confirmed a genetic causal relationship between IMIDs and periodontal disease, thereby unveiling novel potential mechanisms underlying IMIDs and periodontal disease. This discovery is promising in fostering interdisciplinary collaboration between clinicians and stomatologists to facilitate appropriate and precise screening, prevention, and early treatment of IMIDs and periodontal disease.

Exploring Sjögren's syndrome through interdisciplinary perspectives: a concise review

Dr. Henrik Sjögren after whom Sjögren's Syndrome is named, was a Swedish ophthalmologist who identified the syndrome which had three main symptoms namely, dry eyes, dry mouth, and arthritis. His contributions also highlighted the systemic complications of the syndrome which made our understanding of this disease better. Since then, there have been several studies on Sjögren's Syndrome (SS) of which two of them have changed the perception of the disease's prevalence. The first was a British study in the late 1990s which indicated this syndrome was no more a rare condition. The second is a 2008 study in the US which placed the syndrome as the second most prevalent autoimmune disease after rheumatoid arthritis (RA). Being one of the most prevalent autoimmune disease, there is a pressing need for a more profound and comprehensive understanding of the syndrome. This review endeavors to offer a comprehensive overview of the disease, encompassing its prevalence, manifestations, mechanisms, genetic factors, diagnostic methods, and treatment options. This review additionally offers the āyurvedic viewpoint on SS and its symptoms. This supplementary insight has the potential to contribute to the development of an integrated and holistic approach to managing the condition.

Periodontitis and Sjogren's syndrome: a bidirectional two-sample mendelian randomization study

OBJECTIVES

Observational studies indicated a controversial relationship between periodontitis (PD) and Sjogren's syndrome (SS). To overcome restrictions in conventional observational studies, we conducted a two-sample Mendelian randomization (MR) analysis to assess the potential bidirectional relationship between PD and SS.

METHODS

We utilized the largest available genome-wide association study (GWAS) of European ancestry on both PD (17,353 cases-28,210 controls) and SS (2495 cases-365,533 controls) for MR genetic instrument selection. The random-effect inverse-variance weighted (IVW) method complemented by Causal Analysis Using Summary Effect (CAUSE), weighted median, weighted mode, simple mode, MR-Egger regression, and MR-pleiotropy residual sum and outlier (MR-PRESSO) was used for MR analysis. Subsequent pleiotropy and heterogeneity tests were conducted.

RESULTS

IVW analysis exhibited neither an effect of PD on SS (OR = 0.939, 95%CI = 0.525-1.677, P = 0.8304) nor that of SS on PD (OR = 1.007, 95%CI = 0.977-1.038, P = 0.6440). The other five complementary methods further recognized the null association with an effect size close to one. No significant pleiotropy was detected in the relationship between PD and SS (P > 0.05). Heterogeneity existed in the effect of PD on SS but not vice versa.

CONCLUSIONS

No genetic causality between PD and SS or vice versa was supported by our results under MR assumptions and limitations. The study results provided new insights into the relationship between periodontal status and sjogren's syndrome, highlighting the need for a more prudent medical intervention.

Sjögren's Disease and Oral Health: A Genetic Instrumental Variable Analysis

Epidemiological studies have consistently shown that Sjögren's disease (SjD) increases the risk of dental caries. Despite similar evidence indicating an elevated risk of periodontitis, SjD remains a disputed risk factor for this disease. The risk of bias in observational research is a major impediment to confirming this link. Within an instrumental variable framework, genetic variants associated with a risk factor can be used to proxy its effect on an outcome while avoiding common sources of observational study bias. In this study, we leveraged an instrumental variable approach to investigate whether SjD affects the risk of caries and periodontitis. A total of 57 genetic variants strongly associated with SjD were identified from a genome-wide association study of 2,247 European descent cases and 332,115 controls. We tested for associations of these genetic instruments with caries (measured as the number of decayed, missing, and filled surfaces in 26,792 individuals) and periodontitis (17,353 clinical periodontitis cases and 28,210 European controls). Several sensitivity analyses were used to further validate the primary inverse variance weighted (IVW) estimate. IVW analysis revealed an adverse effect of SjD on caries (β = 0.039, P = 6.3e-16) and periodontitis (odds ratio = 1.033, P = 2.3e-05). Sensitivity analyses, conducted to assess the robustness to potential violations of instrumental variable assumptions, further support these findings. Our results showed that SjD has a detrimental effect on caries and also suggest that SjD promotes periodontitis.

Clinical Evaluation of Periodontal Status and IL-6 Gingival Fluid Level in Patients with Sjogren's Syndrome

The objective of the cross-sectional study was to assess periodontal and implant health condition among individuals diagnosed with Sjogren's Syndrome (SS), taking into account the clinical circumstances associated with this patient population. The clinical parameters employed to evaluate the periodontal status of both natural teeth and implants included: periodontal probing depth (PPD) measured at six sites per tooth/implant, clinical attachment level (CAL), bleeding on probing index (BOP), plaque index (PLQ). Gingival crevicular fluid samples were collected for interleukin-16 level evaluation. After clinical and immunological assessment of the study and control groups, the data was centralized, compiled and submitted for statistical analysis. In all four types of assessed periodontal parameters, there were statistically significant differences between the SS patients with no dental implants and the other test (SSi) and control groups (Cni and Ci). Nevertheless, in SS patients with dental implants, plaque levels were similar to that of controls. In addition, other periodontal parameters (PPD, BOP and CAL) were similar in SS patients with dental implants and controls, with no statistically significant difference. The highest GCF IL-6 levels were found in SS patients with no dental implants, the differences to the other study and control groups being statistically significant. In patients with SS and dental implants, there were no statistically significant differences to the other groups. Individuals diagnosed with Sjogren's Syndrome (SS) exhibit a less favorable periodontal condition compared to controls without SS. Notably, SS patients who undergo dental implant procedures demonstrate an improvement in their periodontal status. This highlights the importance of proactive and ongoing dental and periodontal surveillance for SS patients, aiming to decrease the risk of developing periodontal diseases.