Two-sample Mendelian Randomization Study Research Articles

Relationships between emotional states, bipolar disorder, and gastrointestinal disorders: A two-sample Mendelian randomization study

BackgroundFunctional gastrointestinal symptoms are frequently observed in patients with bipolar affective disorder, but the causal relationship between these conditions remains unclear. To establish causality, this study utilized Mendelian randomization (MR) with data from large-scale genomic research. The investigation aimed to elucidate the relationship between emotional states, bipolar disorder, and functional gastrointestinal disorders (FGIDs). MethodsSummary statistics from GWAS were utilized for mood swings (UK biobank, N = 451,619), irritable mood (UK biobank, N = 373,733), bipolar disorder (UK biobank, N = 352,006),functional dyspepsia (FinnGen biobank, N = 194,071), and irritable bowel syndrome (UK biobank, N = 486,601). All GWAS summary statistics were derived from individuals of European ancestry. The primary analysis employed the inverse variance-weighted method for Mendelian randomization (MR). Additionally, we conducted tests for heterogeneity and pleiotropy to ensure the robustness of our results. ResultsA suggestive positive causal relationship was identified between mood swings-related conditions and IBS using the inverse variance-weighted (IVW) method [mood swings-IBS: OR/95%CI: 3.221(2.417,4.294), P(1.42E−15); irritable mood-IBS: OR/95%CI: 1.881(1.615,2.191), P(4.56E−16); bipolar disorder-IBS: OR/95%CI: 1.003(1.001,1.006), P(0.009)]. For functional dyspepsia, a suggestive positive causal relationship was observed with mood swings [mood swings-FD: OR/95%CI: 2.827(1.124,7.109), P(0.027)]. In the reverse analysis, causal relationship was observed between IBS and emotional states [IBS and mood swings: OR/95%CI: 1.030(1.021,1.040), P(1.10E−10); IBS and irritable mood: OR/95%CI: 1.064(1.041,1.087), P(2.58E−08)]. ConclusionsMood swings, irritable mood, and bipolar disorder were associated with an increased risk of functional gastrointestinal disorders (FGIDs). Additionally, reverse analysis revealed a causal relationship between irritable bowel syndrome (IBS) and both mood swings and irritable mood. These findings suggest that targeted emotional interventions may be beneficial for patients with FGIDs. Further research is warranted to explore the relationship between mood instability-related disorders and FGIDs, particularly IBS.

Assessing the causal relationship between CRP, IL-1α, IL-1β, and IL-6 levels and intervertebral disc degeneration: a two-sample Mendelian randomization study

Growing research has suggested an association between chronic inflammation and Intervertebral disc degeneration (IVDD), but whether there is a causal effect remains unknown. This study adopted two-sample Mendelian randomization (MR) approach to explore the etiological role of chronic inflammation in IVDD risk. Here, summary statistics for C-reactive protein (CRP), interleukin (IL)-1α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {\\alpha }$$\\end{document}, IL-1β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {\\beta }$$\\end{document}, IL-6 expression and IVDD were obtained from genome-wide association studies (GWAS) of European ancestry. MR analyses were conducted by using inverse variance weighted (IVW), Wald Ratio, weighted median, and MR-Egger method. Sensitivity analyses were conducted to assess the robustness of the results. The MR analyses suggested a lack of causal association of CRP, IL-6 , and IL-1α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {\\alpha }$$\\end{document} levels on IVDD (CRP-IVDD: odds ratio [OR] = 0.97, 95% confidence interval [CI] 0.86–1.09, P = 0.583; IL-6-IVDD: OR = 1.04, 95% CI 0.86–1.27, P = 0.679; IL-1α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {\\alpha }$$\\end{document}-IVDD: OR = 1.09, 95%CI 1.00–1.18, P = 0.058). However, there was a sign of a connection between genetically elevated IL-1β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {\\beta }$$\\end{document} levels and a decreased IVDD incidence (OR = 0.87, 95%CI 0.77–0.99, P = 0.03). Our findings suggest a connection between IL-1β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {\\beta }$$\\end{document} levels and the risk of IVDD. However, due to the support of only one SNP, heterogeneity and pleiotropy tests cannot be performed, the specific underlying mechanisms warrant further investigation.

Circulating levels of cytokines and risk of urologic cancers: a two-sample Mendelian randomization study

BackgroundChronic inflammation is associated with the etiology of various cancers. However, there is a lack of systematic research in urologic cancers. This study aims to use a two-sample Mendelian randomization (MR) approach to evaluate the role of circulating cytokines in the development of urologic cancers.MethodsWe obtained the summary-level data for bladder cancer (373,295 cases and 372,016 controls), prostate cancer (462,933 cases and 459,664 controls), and kidney cancer (463,010 cases and 461,896 controls) from the UK Biobank. Genetic variations linked to 41 circulating cytokines were used as instrumental variables (IVs) in meta-analyses of genome-wide association studies (GWASs) involving 8,293 individuals from Finland. We primarily used the inverse-variance weighted (IVW) method to assess the potential associations between the 41 cytokines and the risk of 3 common urologic cancers. Weighted-median method, weighted mode and simple-median method were used to assess the sensitivity. Heterogeneity and pleiotropic outlier were evaluated by Cochran's Q test and MR-Egger regression. Genetic correlation, colocalization analysis and multivariable MR analysis were used to further validate the potential pleiotropy.ResultsAfter the Bonferroni correction, there was an observed association between elevated genetically predicted levels of CCL27 and a heightened risk for bladder cancer. Conversely, IL-12p70 levels were found to have a protective association against the risk of bladder cancer. Sensitivity analyses utilizing various IV sets and MR approach remained robust. Furthermore, we found potential associations of 7 cytokines with urologic cancers (4.07 × 10−4 ≤ P < 0.05).ConclusionOur study supported causal associations between CCL27, IL-12p70 and bladder cancer risk and potential associations of 7 cytokines with the risk of urologic cancers, helping us to further understand the pathogenesis of urologic cancers and providing clues for improving diagnostic accuracy and therapies.

Ischemic stroke and sarcopenia have an asymmetric bidirectional relationship based on a two-sample Mendelian randomization study.

We investigated the potential relationship between age-related conditions, particularly sarcopenia and ischemic stroke (IS), through a two-sample Mendelian randomization (MR) study. We conducted a two-sample bidirectional MR study to investigate the relationship between sarcopenia and stroke. Genetic instruments for sarcopenia were derived from the UK Biobank, while data on IS and its subtypes were obtained from the MEGASTROKE consortium. Inverse variance weighting (IVW) served as the primary analytical method. Additionally, heterogeneity and pleiotropy were assessed to ensure the robustness of the findings. The analysis indicates a negative correlation between appendicular lean mass (ALM) and small vessel stroke (SVS; OR = 0.790, 95% CI: 0.703-0.888, p < 0.001), a positive correlation with cardioembolic stroke (CES; OR = 1.165, 95% CI: 1.058-1.284, p = 0.002), and no causal relationship with any ischemic stroke (AIS) or large artery stroke (LAS). Additionally, SVS is negatively associated with right-hand grip strength (OR = 0.639, 95% CI: 0.437-0.934, p = 0.021), while AIS, LAS, and CES do not exhibit a causal relationship with grip strength. Furthermore, no causal relationship was identified between left-hand grip strength, usual walking pace, and IS or its subtypes. MR analysis reveals only a negative association between CES and usual walking pace (OR = 0.989, 95% CI: 0.980-0.998, p = 0.013), with no associations found between other IS subtypes and sarcopenia-related traits. This study demonstrates that a reduction in ALM and right-hand grip strength is associated with SVS, whereas decreased ALM may serve as a protective factor against CES. Conversely, our analysis suggests that CES can impact walking speed. Overall, these findings provide valuable insights into the prevention and treatment of these conditions.

Impact of Gut Microbiota and Inflammatory Cytokines on Immune Thrombocytopenia.

Immune thrombocytopenic purpura (ITP) is an autoimmune disorder, and recent research suggests that gut microbiota and inflammatory cytokines may play a significant role in its pathogenesis. However, the specific effects of these factors on ITP and their relationships remain unclear. We conducted a two-step, two-sample Mendelian randomization study using an inverse variance-weighted approach to investigate the causal role of the gut microbiota in ITP and the mediating effect of inflammatory cytokines on their association. The results showed that among the 473 gut microbiota species, 11 were positively associated and 12 were negatively associated with the risk of ITP. Among the 91 screened inflammatory cytokines, five (CXCL10, CXCL5, IL-12RA, TRAIL, and VEGF-A) were found to have a causal relationship with ITP. Mediation analysis revealed that the gut microbiota UBA1066 promoted the occurrence of ITP through CXCL10 mediation, with a mediation effect of 0.118932 (95% CI: 0.049471-0.188393) accounting for 9.95% of the total effect. Gut microbiota Treponema promoted ITP through VEGF-A mediation, with a mediation effect of 0.045873 (95% CI: 0.01456-0.07718) accounting for 4.28% of the total effect. Gut microbiota Haloplasma promoted the occurrence of ITP via CXCL5. The mediating effect of CXCL5 was 0.038409 (95% CI = 0.00107718-0.07575082), with a mediating ratio of 16.79%. This study revealed a causal relationship between gut microbiota composition and ITP risk, highlighting three inflammatory cytokines as potential causal mediators of this relationship. These findings provide potential targets and biomarkers for the prevention and treatment of ITP with significant clinical implications.

The Relationship between Negative Emotions and Atrial Fibrillation: A Mendelian Randomization Study.

The relationship between negative emotions and atrial fibrillation (AF) has garnered significant attention, yet observational studies have yielded contradictory findings regarding the causal associations between the two. Our study sought to provide genetic evidence for a causal relationship between negative emotions and AF through Mendelian randomization (MR) study. Utilizing genetic variations associated with negative emotions and AF as instrumental variables (IVs), a two-sample MR study was implemented. The potential causality between the two was initially assessed by using negative emotions as exposure and AF as outcome. Subsequently, potential reverse causality was evaluated by using AF as exposure and negative emotions as outcome. The inverse variance weighted (IVW) method served as the primary analysis for the two-sample MR, supplemented by weighted median method, MR-Egger regression, Simple mode method, and Weighted mode method. Sensitivity analyses were performed using the MR pleiotropy residual sum and outlier test (MR-PRESSO), Cochran Q test, and leave-one-out analysis to ensure the robustness of the results. The two-sample MR analyses revealed that genetic susceptibility to AF had no potential causal effect on negative emotions (p > 0.05). Conversely, genetic susceptibility to negative emotions was positively correlated with an increased relative risk of AF [odds ratio (OR), 1.173, 95% confidence interval (CI): 1.115-1.235, p = 8.475 × 10-10]. Furthermore, neither horizontal pleiotropy nor heterogeneity was detected in the analysis. Genetic evidence from the study supports a potential causal link between negative emotions and AF. The study suggests that negative emotions may elevate the risk of AF, and the escalation of negative emotions in AF patients is more likely attributable to modifiable factors rather than genetically related factors.

Causal role of 731 immune cells in diabetic nephropathy: a bi-directional two-sample Mendelian randomization study.

The primary cause of end-stage renal disease (ESRD) is diabetic nephropathy (DN), and a growing body of research indicates that immunology plays a part in how DN develops into ESRD. Our objective is to identify causal relationships between various immune invading cells and DN to identify possible targets for immunotherapy. This study used a complete Mendelian randomization (MR) analysis with two samples to identify the underlying mechanism linking immune cell characteristics with DN. Using publicly available genetic data, we investigated the causal link between 731 immune cell profiles and DN risk. Included were four different types of immune systems: morphological parameters (MP), absolute cell (AC), relative cell (RC), and median fluorescence intensities (MFI). The results' robustness, heterogeneity, and horizontal pleiotropy were confirmed through extensive sensitivity analysis. Following FDR (False Discovery Rate correction method) correction, no statistically significant differences were observed; however, six immunophenotypes were shown to be significantly associated with DN risk at the 0.25 level. Only CD28+ CD4- CD8- T cells were identified as the protective immunophenotype (OR = 0.588, 95% CI 0.437-0.792, P = 4.71 × 10-4). Moreover, DN had no discernible impact on immunophenotyping after FDR correction. Surprisingly, three unadjusted phenotypes with low P values were discovered to be positively correlated with the risk of DN: CD20 on IgD- CD27- B cells (OR = 1.263, 95% CI 1.076-1.482, P = 4.22 × 10-3), CD8 on naive CD8 + T cells with Effector Memory (OR = 1.107, 95% CI 1.013-1.209, P = 2.40 × 10-2), and CD8 on Effector Memory CD8 + T cells (OR = 1.126, 95% CI 1.024-1.239, P = 1.46 × 10-2). Our findings provide a genetic basis for the association between immune cells and DN and should inform future clinical research.

Gut microbiota causally impacts adrenal function: a two-sample mendelian randomization study

Some studies have reported that the gut microbiota can influence adrenal-related hormone levels. However, the causal effects of the gut microbiota on adrenal function remain unknown. Therefore, we employed a two-sample Mendelian randomization (MR) study to systematically investigate the impact of gut microbiota on the function of different regions of the adrenal gland. The summary statistics for gut microbiota and adrenal-related hormones used in the two-sample MR analysis were derived from publicly available genome-wide association studies (GWAS). In the MR analysis, inverse variance weighting (IVW) was used as the primary method, with MR-Egger, weighted median, and cML-MA serving as supplementary methods for causal inference. Sensitivity analyses such as the MR-Egger intercept test, Cochran’s Q test, and leave-one-out analysis were used to assess pleiotropy and heterogeneity. We identified 27 causal relationships between 23 gut microbiota and adrenal function using the IVW method. Among these, Sellimonas enhanced the function of the adrenal cortex reticularis zone (beta = 0.008, 95% CI: 0.002–0.013, P = 0.0057). The cML-MA method supported our estimate (beta = 0.009, 95% CI: 0.004–0.013, P = 2 × 10− 4). Parasutterella, Sutterella, and Anaerofilum affect the functioning of different regions of the adrenal gland. Notably, pleiotropy was not observed. Our findings revealed that the gut microbiota is causally associated with adrenal function. This enhances our understanding of the gut-microbiota-brain axis and provides assistance in the early diagnosis and treatment of adrenal-related diseases in clinical practice.

Genetic Determinants of Telomere Length and Risk of Aneurysmal Subarachnoid Hemorrhage: A Bidirectional Two-Sample Mendelian Randomization Study

Background Our objective is to investigate the potential causal relationship between telomere length (TL) and aneurysmal subarachnoid hemorrhage (aSAH) and intracranial aneurysms (IAs) by conducting a bidirectional two-sample Mendelian Randomization (MR) study. Methods We utilized publicly available summary data from genome-wide association studies (GWAS) for comprehensive analysis. Telomere length-associated data were sourced from the Epidemiology Unit (IEU) GWAS database (n = 472,174), while data pertaining to intracranial aneurysms were derived from a GWAS meta-analysis conducted by Bakker et al, encompassing aneurysmal subtypes including aSAH (n = 77,074), IAs (n = 79,429), and unruptured intracranial aneurysms (uIA) (n = 74,004), all sampled from European populations. The primary method for MR analysis employed was the Inverse Variance Weighted (IVW) method. Additionally, we conducted various sensitivity analyses to assess the heterogeneity and pleiotropy of study findings. Reverse MR analysis was employed to explore potential reverse causality. Results In the forward MR analysis, the IVW method indicated a negative association between TL and aSAH (OR = 0.636, 95% CI: 0.459–0.883, p = 0.006) as well as IAs (OR = 0.670, 95% CI: 0.499–0.900, p = 0.0079). There was no evidence of heterogeneity or horizontal pleiotropy in the forward MR analysis. Reverse MR analysis did not reveal any causal relationship between aSAH, IAs, uIA and TL. Conclusions In European populations, there exists a causal relationship between longer TL and reduced risks of aSAH and IAs Further research is warranted to elucidate the underlying mechanisms and the potential of TL as an intervention target for lowering the incidence of aSAH and IAs.

Causal relationship between beta-2 microglobulin and B-cell malignancies: genome-wide meta-analysis and a bidirectional two-sample Mendelian randomization study.

Beta-2 microglobulin (β2M) is acknowledged as a prognostic biomarker for B-cell malignancies. However, insights into the impact of β2M on B-cell malignancy risk, and vice versa, are limited. We conducted a genome-wide meta-analysis (GWMA), bidirectional two-sample Mendelian randomization (TSMR) analysis, and pathway enrichment analysis to explore the causal relationship between β2M and B-cell malignancies and the underlying biological processes. The GWMA identified 55 lead SNPs across five genomic regions (three novel: WDR72, UMOD, and NLRC5) associated with β2M. In the UKB, genetically predicted β2M showed a positive association with diffuse large B-cell lymphoma (DLBCL; odds ratio [OR]: 1.742 per standard deviation increase in β2M; 95% confidence interval [CI]: 1.215-2.498; P = 3.00 × 10-3; FDR = 7.50× 10-3) and Hodgkin lymphoma (HL; OR: 2.270; 95% CI: 1.525-3.380; P = 5.15 × 10-5; FDR =2.58 × 10-4). However, no associations were found with follicular lymphoma (FL), chronic lymphoid leukemia (CLL), or multiple myeloma (MM). Reverse TSMR analysis revealed no association between genetically predicted B-cell malignancies and β2M. In FinnGen, β2M was found to be associated with an increased risk of DLBCL (OR: 2.098; 95% CI: 1.358-3.242; P = 8.28 × 10-4; FDR = 4.14 × 10-3), HL (OR: 1.581; 95% CI: 1.167-2.142; P = 3.13 × 10-3; FDR = 5.22 × 10-3), and FL (OR: 2.113; 95% CI: 1.292-3.455; P = 2.90 × 10-3; FDR = 5.22 × 10-3). However, no association was found with CLL or MM. Reverse TSMR analysis indicated that genetically predicted DLBCL, FL, and MM may perturb β2M levels. Pathway enrichment analysis suggested that the innate immune system represents a convergent biological process underlying β2M, DLBCL, and HL. Our findings suggested that elevated levels of β2M were associated with an increased risk of DLBCL and HL, which is potentially linked to dysfunction of the innate immune system.

7729 Autoimmune Thyroid Disease And Risk of Premature Ovarian Failure - A Comprehensive Analysis Combining Observational Studies, Two-sample Mendelian Randomization Study, And Targeted Drug Forecast

Abstract Disclosure: R. Wang: None. T. Dou: None. L. Guan: None. X. Qi: None. X. Wang: None. C. Yu: None. Q. Guan: None. Premature ovarian failure (POF), a condition impacting women's fertility and physical well-being. Specifically, autoimmune thyroid disease (TAI) is recognized as an organ-specific autoimmune condition that may co-occur with POF in clinical scenarios, yet the precise nature of their relationship remains uncertain. The objective of this study is to investigate the influence of TAI on ovarian function, identify shared pathogenic genes, predict potentially effective drugs, and establish a foundation for clinical interventions. Firstly, a case-controlled study was conducted using the Nationwide Readmissions Database (NRD) in the United States. This involved identifying patients with Hashimoto's thyroiditis (HT) and Graves' disease (GD) as the study group, and those without deficiency as the control group, to explore the correlation with POF. Additionally, an Asian population-based case group comprising 897 patients with POF and a control group of 897 healthy women were gathered to analyze the association of POF with TAI-related antibodies, namely TGAb and TPOAb. Furthermore, a two-sample Mendelian randomization(MR) study was undertaken in European populations to investigate the causal relationship between TAI and POF. Lastly, genes associated with HT, GD, and POF were compiled from the GEO, GeneCards, and DisGeNET databases, and common genes were identified through intersection. Subsequent gene ontology and pathway enrichment analyses, protein-protein interaction analyses, and candidate drug predictions were performed based on the shared genes. The findings revealed a significant association between TAI and POF in the NRD, with patients exhibiting TAI being notably more prone to POF compared to the control group (OR 1.78, 1.34-2.35, P&amp;lt;0.001). Subgroup analysis further demonstrated an increased risk of POF in patients with HT (OR 1.51, 1.02-2.22, P&amp;lt;0.05) and GD (OR 2.18, 1.45-3.29, P&amp;lt;0.05). In the Asian population, a retrospective analysis indicated a positive correlation between TPOAB positivity and POF (OR 1.76, 1.24-2.51, P&amp;lt;0.05). MR analysis unveiled a causal relationship between GD and POF. Through a comprehensive examination of multiple gene databases, 47 common genes were identified between HT and POF, and 20 common genes between GD and POF. Enrichment analysis demonstrated relative similarities in cytokines and signal transduction, apoptosis, inflammatory response, and other aspects between HT and POF. GD was found to potentially influence ovarian function through pathways such as the PI3K-Akt signaling pathway and adhesive plaques. Dexamethasone, rapamycin, and other drugs emerged as potential therapeutic options for both diseases. In summary, our study suggests that TAI, particularly GD, may elevate the risk of POF. Additionally, we predict potential therapeutic drugs, and shed light on the potential biological mechanisms linking HT/GD and POF. Presentation: 6/3/2024

The causal relationship between rheumatoid arthritis and interstitial lung disease in East Asian population: A two-sample Mendelian randomization study.

To investigate the causal relationship between rheumatoid arthritis (RA) and interstitial lung disease (ILD) in the East Asian population, we utilized Mendelian randomization (MR). Publicly available summarized data from genome-wide association studies on RA (4199 cases and 208,254 controls), and the data on ILD (1046 cases and 176,974 controls) were obtained from BioBank Japan. Eligible single nucleotide polymorphisms from East Asian populations were obtained from genome-wide association studies as instrumental variables, and 11 RA-related single nucleotide polymorphisms (P < 5 × 10-8) were selected as instrumental variables. MR analysis was performed using inverse variance weighted, MR-Egger regression, weighted median, and MR-PRESSO with RA as the exposure data and ILD as the outcome data. Reliability was evaluated using Cochran Q test, MR-Egger intercept, leave-one-out analysis, and funnel plot. Inverse variance weighted results showed an odds ratio (95% confidence interval) of 1.29 (1.18-1.41), P = 3.99 × 10-8, indicating a positive association between RA and ILD. The reliability evaluation could adopt the fixed-effect model, and the absolute value of the MR-Egger regression intercept was 0.021, P > 0.05, and P value of Global Test in MR-PRESSO was 0.573. The test results of the leave-one-out showed that the results are robust, and the funnel plot indicated that the instrumental variables were not affected by potential factors. In conclusion, this study demonstrates that RA is a risk factor for ILD in the East Asian population.

Uric acid levels and cardiovascular and cerebrovascular diseases: a Mendelian randomization study.

The relationship between uric acid (UA) levels and cardiovascular and cerebrovascular diseases (CCVD) is controversial. A two-sample Mendelian randomization (MR) study was conducted to explore the causal effects of UA levels on CCVD. Genetic variants strongly associated with UA levels were selected as instrumental variables from the Genome-Wide Association Study (GWAS) dataset. The GWAS data, sourced from the Global Urate Genetics Consortium (GUGC), comprised a sample size of 110,347 individuals. The selected CCVD outcomes included stroke, coronary artery disease (CAD), as well as atrial fibrillation and flutter. The primary analytical approach employed the inverse-variance weighted (IVW) method, supplemented by MR-Egger and weighted median as complementary methods. Sensitivity analysis was performed to test heterogeneity and pleiotropy. The MR analysis results indicated a causal association between UA levels and stroke (OR: 1.002; 95% CI: 1.000-1.003; p = 0.036), CAD (OR: 1.118; 95% CI: 1.044-1.197; p = 0.001), as well as atrial fibrillation and flutter (OR: 1.141; 95% CI: 1.037- 1.256; p = 0.007). The results of MR-Egger and weighted median methods confirmed the direction of the IVW results, enhancing the robustness of the findings. No significant anomalies were detected in the sensitivity analysis. The MR study suggests that UA levels exert causal effects on stroke, CAD, as well as atrial fibrillation and flutter.

The Causal Relationship between Inflammatory Cytokines and Liver Cirrhosis in European Descent: A Bidirectional Two-Sample Mendelian Randomization Study and the First Conclusions.

Observational studies have highlighted the pivotal role of inflammatory cytokines in cirrhosis progression. However, the existence of a causal link between inflammatory cytokines and cirrhosis remains uncertain. In this study, we conducted a bidirectional Mendelian randomization (MR) analysis at a summarized level to illuminate the potential causal relationship between the two variables. This study utilized genetic variance in cirrhosis and inflammatory cytokines from a genome-wide association study (GWAS) of European descent. The MR-PRESSO outlier test, Cochran's Q test, and MR-Egger regression were applied to assess outliers, heterogeneity, and pleiotropy. The inverse variance weighted method and multiple sensitivity analyses were used to evaluate causalities. Furthermore, the validation set was used for simultaneous data validation. The inflammatory cytokine monocyte chemoattractant protein 3 (MCP-3) was supposedly associated with a greater risk of cirrhosis. And cirrhosis was significantly correlated with increased levels of hepatocyte growth factor (HGF). This study suggests that MCP-3 might be associated with the etiology of cirrhosis, while several inflammatory cytokines could potentially play a role in its downstream development. Additionally, the progression of cirrhosis was associated with elevated levels of HGF, suggesting a possible role for liver repair functions.

Reply to "Commentary: 'No Genetic Causality between Tobacco Smoking and Venous Thromboembolism: A Two-Sample Mendelian Randomization Study' ".

Reply to "Commentary: 'No Genetic Causality between Tobacco Smoking and Venous Thromboembolism: A Two-Sample Mendelian Randomization Study' ".

Impact of systemic lupus erythematosus on cardiovascular morphologic and functional phenotypes: a Mendelian randomization analysis.

Previous studies have established a correlation between systemic lupus erythematosus (SLE) and cardiovascular health, but the potential causal effects of SLE on heart function and structure remain poorly understood. Cardiovascular magnetic resonance imaging (CMR), a novel non-invasive technique, provides a unique assessment of cardiovascular structure and function, making it an essential tool for evaluating the risk of heart disease. In this study, we performed a Mendelian randomization analysis to determine the causal relationship between SLE and CMR traits. Genetic variants independently linked to SLE were selected from a genome-wide association study (GWAS) containing 5,201 cases and 9,066 controls as instrumental variables. A set of 82 CMR traits was obtained from a recent GWAS, serving as preclinical indicators and providing preliminary insights into the morphology and function of the four cardiac chambers and two aortic segments. Primary analysis employed a two-sample Mendelian randomization study using the inverse-variance weighted method. Heterogeneity testing, sensitivity analyses, and instrumental variable strength assessments confirmed the robustness of the findings. SLE exhibited a correlation with increased stroke volume (βLVSV = 0.007, P = 0.045), regional peak circumferential strain (βEcc_AHA_9 = 0.013, P = 0.002; βEcc_AHA_12 = 0.009, P = 0.043; βEcc_AHA_14 = 0.013, P = 0.006), and global peak circumferential strain of the LV (βEcc_global = 0.010, P = 0.022), as well as decreased regional radial strain (βErr_AHA_11 = -0.010, P = 0.017). This research presents evidence of a potential causal association between traits of SLE and alterations in cardiac function, guiding cardiac examinations and disease prevention in lupus patients.

Causal effects of plasma metabolites on autoimmune hepatitis (AIH): a bidirectional two-sample mendelian randomization study

Autoimmune hepatitis(AIH) is a chronic progressive inflammatory liver disease induced by loss of immune tolerance. The role of circulating metabolites in disease pathogenesis is unclear. This study aimed to investigate potential causal links between plasma metabolites and AIH risk by employing a two-sample Mendelian randomization approach. A comprehensive bidirectional two-sample Mendelian randomization analysis was conducted using genome-wide significant variant-metabolite and variant-AIH associations in European ancestry individuals. Various methods assessed causal relationships among 1400 metabolites and AIH, incorporating sensitivity analyses to evaluate pleiotropy and heterogeneity. Fifty-eight metabolites displayed possible associations, including increased AIH risk with genetically predicted higher kynurenine (p = 2.79 × 10− 5, OR: 1.64, 95% CI 1.30–2.07) and a protective effect for the dopamine sulfate ratio (p = 1.06 × 10− 5,OR: 0.62, 95% CI 0.49–0.79). Reciprocal analysis revealed a causal effect of AIH on kynurenine( p = 2.79 × 10− 5, OR: 1.64, 95% CI 1.30–2.07), but not on the dopamine sulfate ratio(p = 0.691, OR: 1.05, 95% CI 0.67–1.64). Our genetics-based approach provides evidence supporting a causal role for specific metabolite levels in AIH risk. The results deliver evidence supporting a causal effect of a specific metabolite ratio(dopamine 4-sulfate/dopamine 3-O-sulfate) on AIH risk. Experimental validation and mechanistic examinations are warranted to confirm findings.

Antioxidants and the risk of sleep disorders: results from NHANES and two-sample Mendelian randomization study

BackgroundSleep disorders have emerged as a major public health concern. Observational research indicates that antioxidants might mitigate the risk of sleep disturbances, yet the causal relationship remains uncertain.Materials and methodsThis study utilized data from the National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2018, focusing on adults who reported sleep disorders. The analysis included 25,178 American adults. We examined the association between the Composite Dietary Antioxidant Index (CDAI) and the prevalence of sleep disorders. Additionally, a two-sample Mendelian randomization analysis was conducted to explore the potential causal link between CDAI and the risk of sleep disorders.ResultsAnalysis of data from the 2011–2018 NHANES survey revealed a significant negative association between CDAI and sleep disorders (OR = 0.854, 95% CI 0.821–0.888, P &amp;lt; 0.001). A multivariable logistic regression model showed that each unit increase in CDAI corresponded to a 14.6% reduction in sleep disorder risk, exhibiting a nonlinear trend where the risk decreased until reaching the inflection point of −0.134. Additionally, MR analysis demonstrated that genetically determined selenium reduces the risk of OSA (OR = 0.992, 95% CI 0.860–0.989, P = 0.023). Furthermore, vitamin E (γ-tocopherol) and vitamin C were protective against sleep-wake disorders (OR = 0.016, 95% CI 0.001–0.674, P = 0.03) and (OR = 0.049, 95% CI 0.007–0.346, P = 0.002), respectively.ConclusionDietary antioxidants may help prevent sleep disorders. However, further studies are required to clarify the pathways through which antioxidants exert this protective effect.

Investigating the Causal Relationship Between Gut Microbiota and Allergic Conjunctivitis: A Two-Sample Mendelian Randomization Study

ABSTRACT Purpose To investigate the causal association between gut microbiota and allergic conjunctivitis. Methods A two-sample Mendelian randomization (MR) analysis was performed using the summary statistics of gut microbiota (18,340) from MiBio-Gen consortium and allergic conjunctivitis data (n = 218,792) obtained from the IEU Open GWAS project. F-statistics and sensitivity analyses were used to address potential biases and ensure the reliability of our findings. Reverse MR analysis was conducted to assess the possible of reverse causal relationships. Results The inverse variance weighted estimates revealed the protective potential of the phylum Euryarchaeota against allergic conjunctivitis (OR = 0.87, p = 6.17 × 10−4). On the other hand, the genus Christensenellaceae R.7 group (OR = 0.75, p = 2.89 × 10−3), family Peptostreptococcaceae (OR = 0.83, p = 6.22 × 10−3), genus Lachnospiraceae FCS020 group (OR = 0.82, p = 0.02) all showed a suggestive protective association with allergic conjunctivitis. Additionally, sensitivity analysis confirmed the robustness of the above associations. In the reverse MR analysis, no significant causal association was found between gut microbiota and allergic conjunctivitis. Conclusion This study has revealed a potential causal correlation between the phylum Euryarchaeota and allergic conjunctivitis, offering new insights to improve prevention and treatment of this condition.

Genetically predicted 486 blood metabolites in relation to risk of esophageal cancer: a Mendelian randomization study.

Enhancing therapy choices for varying stages of esophageal cancer and improving patient survival depend on timely and precise diagnosis. Blood metabolites may play a role in either causing or preventing esophageal cancer, but further research is needed to determine whether blood metabolites constitute a genetic risk factor for the disease. In order to tackle these problems, we evaluated the causal association between esophageal cancer and 486 blood metabolites that functioned as genetic proxies using a two-sample Mendelian randomization (MR) study. We utilized two-sample MR analyses to evaluate the causal links between blood metabolites and esophageal cancer. For the exposure, we used a genome-wide association study (GWAS) of 486 metabolites, and a GWAS study on esophageal cancer from Sakaue et al. was used for preliminary analyses. Causal analyses employed randomized inverse variance weighted (IVW) as the main method, supplemented by MR-Egger and weighted median (WM) analyses. Sensitivity analyses included the MR-Egger intercept test, Cochran Q test, MR-PRESSO, and leave-one-out analysis. Additionally, independent esophageal cancer GWAS data were utilized for replication and meta-analysis. FDR correction was applied to discern features with causal relationships. For conclusive metabolite identification, we conducted Steiger tests, linkage disequilibrium score regression, and colocalization analyses. Moreover, we utilized the program MetaboAnalyst 5.0 to analyze metabolic pathways. This study found an important association between esophageal cancer and three metabolites: 1-linoleoylglycerophosphoethanolamine* [odds ratio (OR) = 3.21, 95% confidence interval (CI): 1.42-7.26, p < 0.01], pyroglutamine* (OR = 1.92, 95% CI: 1.17-3.17, p < 0.01), and laurate (12:0) (OR = 3.06, 95% CI: 1.38-6.78, p < 0.01). This study establishes a causal link between three defined blood metabolites and esophageal cancer, offering fresh insights into its pathogenesis.