Project description:BackgroundBased on the results of existing observational studies, it can be found that the association between serum vitamin D levels and the risk of Sjogren's syndrome (SS) in humans is still controversial. Based on this situation, this study aimed to assess the causal relationship between serum vitamin D levels and SS by using the Mendelian randomization (MR) approach.MethodsIn this study, genome-wide association studies (GWAS) summary statistics on serum vitamin D levels [sample size = 417,580 (UK Biobank)] and SS [sample size = 416,757 (cases = 2495, controls = 414,262) (FinnGen)] were used. The bi-directional MR analysis was then used to assess possible causal relationships. The major analysis method of MR was performed using inverse-variance weighted (IVW), supplemented by MR-Egger and the weighted median approaches. In addition, sensitivity analyses were used to ensure the stability of the results, including Cochran's Q test, MR-PRESSO, MR-Egger intercept test, and the leave-one-out test.ResultsThe MR suggested that no significant causal effects of serum 25(OH)D levels on SS risks were observed [odds ratio (OR) = 0.9824; 95% confidence interval (CI) = 0.7130 to 1.3538; P = 0.9137]. Similarly, no evidence supported the causal effects of SS on serum vitamin D levels (β: 0.0076, 95% CI: - 0.0031 to 0.0183; P = 0.1640).ConclusionThis study found no obvious evidence that serum vitamin D level is causally associated with SS risks or vice versa. We call for larger sample size studies to further unravel the potential causal relationship and the exact mechanism.
Project description:BackgroundPrevious epidemiological studies have reported an association between Sjögren's syndrome (SS) and Parkinson's disease (PD); however, the causality and direction of this relationship remain unclear. In this study, we aimed to investigate the causal relationship between genetically determined SS and the risk of PD using bidirectional Mendelian randomization (MR).MethodsSummary statistics for Sjögren's syndrome used as exposure were obtained from the FinnGen database, comprising 1,290 cases and 213,145 controls. The outcome dataset for PD was derived from the United Kingdom Biobank database, including 6,998 cases and 415,466 controls. Various MR methods, such as inverse variance weighted (IVW), Mendelian randomization Egger regression (MR-Egger), weighted median (WM), simple mode, weighted mode, MR-pleiotropy residual sum and outlier (MR-PRESSO), and robust adjusted profile score (RAPS), were employed to investigate the causal effects of SS on PD. Instrumental variable strength evaluation and sensitivity analyses were conducted to ensure the reliability of the results. In addition, reverse MR analysis was performed to examine the causal effects of PD on SS.ResultsThe WM, IVW, RAPS and MR-PRESSO methods demonstrated a significant association between genetically predicted SS and reduced risk of PD (odds ratio ORWM = 0.9988, ORIVW = 0.9987, ORRAPS = 0.9987, ORMR-PRESSO = 0.9987, respectively, P < 0.05). None of the MR analyses showed evidence of horizontal pleiotropy (P > 0.05) based on the MR-Egger and MR-PRESSO tests, and there was no statistical heterogeneity in the test results of the MR-Egger and IVW methods. The leave-one-out sensitivity analysis confirmed the robustness of the causal relationship between SS and PD. Furthermore, reverse MR analysis did not support any causal effects of PD on SS.ConclusionOur MR study supports a potential causal association between SS and a reduced risk of PD. Further extensive clinical investigations and comprehensive fundamental research are warranted to elucidate the underlying mechanisms linking SS and PD.
Project description:Primary Sjögren's Syndrome (PSS) and psoriasis are frequently observed to co-occur in clinical settings. However, the causal associations and underlying mechanisms between PSS and psoriasis remain poorly defined. In this study, we conducted bidirectional MR analysis to explore the causal relationship between PSS and psoriasis using four MR methods: inversevariance weighted, MR-Egger regression, weighted median, and weighted mode. Sensitivity analyses were carried out, employing different models and testing methods for comparison to assess the influence of heterogeneity and pleiotropy on our findings and to confirm the robustness of these results. We primarily employed the Inverse Variance Weighting (IVW) method for our analysis. A p-value of less than 0.05 indicates a significant causal relationship, while a p-value greater than 0.05 suggests the absence of such a relationship. The IVW analysis confirmed a causal relationship between psoriasis and primary Sjögren's syndrome (PSS) (OR: 3.149E-10, 95% CI 1.114E-18-0.089, P = 0.028), with the weighted median yielding similar results. Conversely, there was no causal association found between PSS and the risk of developing psoriasis (OR: 1.000, 95% CI 0.999-1.000, P = 0.328). This study reveals a causal relationship between primary Sjögren's syndrome (PSS) and psoriasis, demonstrating that psoriasis increases the risk of developing PSS, while the reverse is not true. This potential causal link offers new insights into the etiology of both PSS and psoriasis.
Project description:ObjectivesObservational 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.MethodsWe 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.ResultsIVW 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.ConclusionsNo 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.
Project description:BackgroundThe link between the gut microbiota (GM) and Sjögren's Syndrome (SS) is well-established and apparent. Whether GM is causally associated with SS is uncertain.MethodsThe MiBioGen consortium's biggest available genome-wide association study (GWAS) meta-analysis (n=13,266) was used as the basis for a two-sample Mendelian randomization study (TSMR). The causal relationship between GM and SS was investigated using the inverse variance weighted, MR-Egger, weighted median, weighted model, MR-PRESSO, and simple model methods. In order to measure the heterogeneity of instrumental variables (IVs), Cochran's Q statistics were utilized.ResultsThe results showed that genus Fusicatenibacter (odds ratio (OR) = 1.418, 95% confidence interval (CI), 1.072-1.874, P = 0.0143) and genus Ruminiclostridium9 (OR = 1.677, 95% CI, 1.050-2.678, P = 0.0306) were positively correlated with the risk of SS and family Porphyromonadaceae (OR = 0.651, 95% CI, 0.427-0.994, P = 0.0466), genus Subdoligranulum (OR = 0.685, 95% CI, 0.497-0.945, P = 0.0211), genus Butyricicoccus (OR = 0.674, 95% CI, 0.470-0.967, P = 0.0319) and genus Lachnospiraceae (OR = 0.750, 95% CI, 0.585-0.961, P = 0.0229) were negatively correlated with SS risk using the inverse variance weighted (IVW) technique. Furthermore, four GM related genes: ARAP3, NMUR1, TEC and SIRPD were significant causally with SS after FDR correction (FDR<0.05).ConclusionsThis study provides evidence for either positive or negative causal effects of GM composition and its related genes on SS risk. We want to provide novel approaches for continued GM and SS-related research and therapy by elucidating the genetic relationship between GM and SS.
Project description:BackgroundPrevious observational studies have reported an association between Sjögren's syndrome (SS) and an increased risk of Parkinson's Disease (PD). However, the causal relationship between these conditions remains unclear. The objective of this study was to investigate the causal impact of SS on the risk of developing PD, utilizing the Mendelian randomization (MR) approach.MethodsWe conducted a bidirectional MR analysis using publicly available genome-wide association studies (GWAS) data. The primary analysis utilized the inverse-variance weighted (IVW) method. Complementary methods, such as MR-Egger regression, weighted mode, weighted median, and MR-pleiotropy residual sum and outlier (MR-PRESSO), were utilized to identify and correct for the presence of horizontal pleiotropy.ResultsThe IVW MR analysis revealed no significant association between SS and PD (IVW: OR = 1.00, 95% CI = 0.94-1.07, P = 0.95). Likewise, the reverse MR analysis did not identify any significant causal relationship between PD and SS (IVW: OR = 0.98, 95% CI = 0.85-1.12, P = 0.73). The results from MR-Egger regression, weighted median, and weighted mode approaches were consistent with the IVW method. Sensitivity analyses suggested that horizontal pleiotropy is unlikely to introduce bias to the causal estimates.ConclusionThis study does not provide evidence to support the assertion that SS has a conclusive impact on the risk of PD, which contradicts numerous existing observational reports. Further investigation is necessary to determine the possible mechanisms behind the associations observed in these observational studies.
Project description:The clinical incidence of sjogren's syndrome combined with gastroesophageal reflux disease is high. Existing observational studies have shown inconsistent results in the association between gastroesophageal reflux disease (GERD) and Sjogren's syndrome (SS).We observed that the symptoms of SS patients also improved after receiving GERD-related treatment. Therefore, we aimed to investigate the relationship between GERD and SS through a bidirectional two-sample Mendelian randomization (MR) study. Independent SNPs associated with GERD and SS were selected from a genome-wide association study (GWAS) as instrumental variables to conduct a bidirectional two-sample Mendelian analysis of GERD and SS. Genetic data were obtained from two databases for the following two outcomes: Gastroesophageal reflux (IEU Open GWAS) [sample size = 602,604 (patients = 129,080; nonpatients = 473,524)] and SS (FinnGen) [sample size = 392,423 (patients = 2,495; nonpatients = 389,928)]. Statistical methods for the MR analysis included the inverse-variance weighting method, weighted median, simple mode and weighted mode, as well as heterogeneity and sensitivity analyses using the Cochran Q statistic, MR‒Egger regression, outlier detection methods (MR-PRESSO). In addition, Steiger Test was conducted to test the direction of causality. MR analysis showed a positive correlation between GERD and SS risk [odds ratio (OR) = 1.3279 (95% confidence interval 1.0312-1.7099, P = 0.0280)]. However, in contrast, no significant causal effect of SS on GERD was observed [OR = 1.0024 (95% CI 0.9651-1.0412; P = 0.8995)]. This bidirectional two-sample Mendelian randomization study confirmed a causal relationship between SS and GERD, and suggested that GERD is a risk factor for SS, while SS does not affect GERD.
Project description:BACKGROUND: Vitamin D deficiency is associated with increased cardiovascular disease risk in observational studies. Whether these associations are causal is not clear. Loss-of-function mutations in the filaggrin gene result in up to 10% higher serum vitamin D concentrations, supposedly due to a decreased UV-protection of the keratinocytes. We used a Mendelian randomization approach to estimate the causal effect of vitamin D status on serum lipids, blood pressure, body mass index, waist circumference, and the metabolic syndrome. METHODS: Three population based studies were included, Monica10 (2,656 individuals aged 40-71 years), Inter99 (6,784 individuals aged 30-60 years), and Health2006 (3,471 individuals aged 18-69 years) conducted in 1993-94, 1999-2001, and 2006-2008, respectively. Participants were genotyped for the two most common filaggrin gene mutations in European descendants R501X and 2282del4, in all three studies and further for the R2447X mutation in the Inter99 and Health2006 studies. Filaggrin genotype was used as instrumental variable for vitamin D status. Baseline measurements of serum 25-hydroxyvitamin D were performed in all three studies. RESULTS: Instrumental variable analyses showed a 23.8% (95% confidence interval, CI 3.0, 48.6) higher HDL cholesterol level and a 30.5% (95% CI: 0.8, 51.3) lower serum level of triglycerides per doubling of vitamin D. These associations were, however, not statistically significant when applying the Bonferroni adjusted significance level. The remaining lipids showed non-significant changes in a favorable direction. Doubling of vitamin D gave a non-significantly lower odds ratio = 0.26 (95% CI: 0.06, 1.17) of the metabolic syndrome. There were no statistically significant causal effects of vitamin D status on blood pressure, body mass index, or waist circumference. CONCLUSION: Our results support a causal effect of higher vitamin D status on a more favorable lipid profile, although more studies in other populations are needed to confirm our results.
Project description:BackgroundSeveral observational studies have explored the associations between Sjögren's syndrome (SS) and certain cancers. Nevertheless, the causal relationships remain unclear. Mendelian randomization (MR) method was used to investigate the causality between SS and different types of cancers.MethodsWe conducted the two-sample Mendelian randomization with the public genome-wide association studies (GWASs) summary statistics in European population to evaluate the causality between SS and nine types of cancers. The sample size varies from 1080 to 372,373. The inverse variance weighted (IVW) method was used to estimate the causal effects. A Bonferroni-corrected threshold of P < 0.0031 was considered significant, and P value between 0.0031 and 0.05 was considered to be suggestive of an association. Sensitivity analysis was performed to validate the causality. Moreover, additional analysis was used to assess the associations between SS and well-accepted risk factors of cancers.ResultsAfter correcting the heterogeneity and horizontal pleiotropy, the results indicated that patients with SS were significantly associated with an increased risk of lymphomas (odds ratio [OR] = 1.0010, 95% confidence interval [CI]: 1.0005-1.0015, P = 0.0002) and reduced risks of prostate cancer (OR = 0.9972, 95% CI: 0.9960-0.9985, P = 2.45 × 10-5) and endometrial cancer (OR = 0.9414, 95% CI: 0.9158-0.9676, P = 1.65 × 10-5). Suggestive associations were found in liver and bile duct cancer (OR = 0.9999, 95% CI: 0.9997-1.0000, P = 0.0291) and cancer of urinary tract (OR = 0.9996, 95% CI: 0.9992-1.0000, P = 0.0281). No causal effect of SS on other cancer types was detected. Additional MR analysis indicated that causal effects between SS and cancers were not mediated by the well-accepted risk factors of cancers. No evidence of the causal relationship was observed for cancers on SS.ConclusionsSS had significant causal relationships with lymphomas, prostate cancer, and endometrial cancer, and suggestive evidence of association was found in liver and bile duct cancer and cancer of urinary tract, indicating that SS may play a vital role in the incidence of these malignancies.
Project description:Study objectivesObservational and cohort studies have associated Sjögren's syndrome (SS) with various types of cardiovascular disease (CVD), yet causal relationships have not been established. We employed Mendelian randomization (MR) to investigate potential causal links between SS and CVD in the general population.MethodsWe conducted a two-sample MR analysis using data from four distinct sources for 11 genome-wide significant single nucleotide polymorphisms (SNPs) associated with SS and data for 13 types of CVD sourced from FinnGen, IEU OpenGWAS, and GWAS catalog. The inverse variance weighted method was selected as the primary analytical approach, complemented by various sensitivity analyses.ResultsMR analyses provide evidence of a significantly increased risk of ischemic stroke associated with genetically predicted SS (odds ratio [OR], 1.0237; 95 % CI, 1.0096 to 1.0379; p = 0.0009), as well as suggestive evidence of a potential causal relationship between SS and an increased risk of chronic heart failure (OR, 1.0302; 95 % CI, 1.0020 to 1.0592; p = 0.0355). Sensitivity analyses reinforced these associations, demonstrating robustness and consistency across multiple statistical methods. The secondary analysis, conducted after outlier correction using MR-PRESSO and RadialMR methods, reaffirmed these associations and also indicated a suggestive causal link between SS and non-rheumatic valvular heart disease (OR, 1.0251; 95 % CI, 1.0021 to 1.0486; p = 0.0323).ConclusionsThis study demonstrates that genetically predicted SS is a potential causative risk factor for ischemic stroke, chronic heart failure, and non-rheumatic valvular heart disease on a large-scale population. However, further research incorporating ancestral diversity is required to confirm a causal relationship between SS and CVD.