Project description:BackgroundAn association has been identified between inflammatory bowel disease (IBD) and frailty; however, the causal nature of this connection remains uncertain. We consequently conducted a two-sample Mendelian randomization (MR) analysis to explore this particular association.MethodsWe acquired distinct datasets for inflammatory bowel disease (IBD), Crohn's disease (CD), ulcerative colitis (UC), and frailty from the published genome-wide association studies (GWAS) database, meticulously selecting instrumental variables (IVs). Subsequently, we employed a bidirection MR to examine the causal relationship between IBD (including CD and UC) and frailty. We utilized statistical methods, with a primary emphasis on inverse-variance weighted (IVW), accompanied by a series of sensitivity analyses to confirm heterogeneity and pleiotropy influenced the outcomes of the MR.ResultsWe found positive causal effects of genetically increased frailty risk on IBD (OR: 1.015, 95% CI 1.005-1.025, P = 0.004). Furthermore, when scrutinizing specific IBD subtypes, both Crohn's disease (CD) and ulcerative colitis (UC) demonstrated an increased predisposition to frailty (OR: 1.018, 95% CI 1.01-1.027, P < 0.05) and (OR = 1.016, 95% CI 1.005-1.027, P < 0.05). Nevertheless, despite the consistent trends observed in the weighted median and MR-Egger regression analyses for both conditions, statistical significance remained elusive. Notably, the results of the inverse MR analysis did not establish an association between frailty and an elevated risk of IBD development.ConclusionsOur research indicates that IBD, encompassing both CD and UC, may augment the propensity for frailty. Clinical practitioners must prioritize early frailty assessment in individuals afflicted with inflammatory bowel disease, inclusive of Crohn's disease and ulcerative colitis, facilitating proactive measures and timely interventions. However, our findings do not provide evidence supporting a causal effect of frailty on IBD (including CD and UC). Consequently, further studies are essential to explore the intricate mechanisms that clarify the effect of frailty on IBD.
Project description:BackgroundPrevious observational studies have found an association between inflammatory bowel disease (IBD) and psoriasis. Using the mendelian randomization (MR) approach, we aim to determine whether there was a causal association between IBD and psoriasis.MethodsWe performed a two-sample MR with the genetic instruments identified for IBD and its main subtypes, Crohn's disease (CD) and ulcerative colitis (UC), from a genome-wide association study (GWAS) involving 25,042 cases with an IBD diagnosis and 34,915 controls. Summarized data for psoriasis were obtained from different GWAS studies which included 4510 cases and 212,242 controls without psoriasis. Causal estimates are presented as odds ratios (ORs) with 95% confidence intervals (CIs).ResultsThe overall outcome of MR analysis was to demonstrate that genetic predisposition to IBD was associated with an increased risk of psoriasis (OR: 1.1271; 95% CI: 1.0708 to 1.1864). Psoriatic arthritis (PsA) had a significant association with total IBD (OR: 1.1202; 95% CI: 1.0491 to 1.1961). Casual relationship was also identified for CD-psoriasis (OR: 1.1552; 95% CI: 1.0955 to 1.2182) and CD-PsA (OR: 1.1407; 95% CI: 1.0535 to 1.2350). The bidirectional analysis did not demonstrate that a genetic predisposition to psoriasis was associated with total IBD, although psoriasis showed association with CD (OR: 1.2224; 95% CI: 1.1710 to 1.2760) but not with UC. A genetic predisposition to PsA had a borderline association with IBD (OR: 1.0716; 95% CI: 1.0292 to 1.1157) and a suggestive association with CD (OR: 1.0667; 95% CI: 1.0194 to 1.1162).ConclusionThere appears to be a causal relationship between IBD and psoriasis, especially for PsA, but for psoriasis and IBD, only total psoriasis and PsA were associated with CD. Understanding that specific types of psoriasis and IBD constitute mutual risk factors facilitates the clinical management of two diseases.
Project description:BackgroundMendelian randomization (MR) was used to evaluate the bidirectional causal relationship between inflammatory bowel disease (IBD) and interleukins (ILs), chemokines.MethodsGenetic instruments and summary data of five ILs and six chemokines were obtained from a genome-wide association study database, and instrumental variables related to IBD were obtained from the FinnGen Consortium. Inverse variance weighting (IVW) was used as the main MR analysis method, and several other MR methods including MR-Egger and weighted median were used to confirm the reliability of the results. Sensitivity analyses such as heterogeneity and pleiotropy were also performed.ResultsThe IVW method provided evidence to support that genetically predicted IL-16, IL-18, and CXCL10 significantly positively correlated with IBD, while IL-12p70 and CCL23 significantly negatively correlated with IBD. IL-16 and IL-18 had a suggestive association with an increased risk of ulcerative colitis (UC), and CXCL10 had a suggestive association with an increased risk of Crohn's disease (CD). However, there was no evidence to support that IBD and two main subtypes (UC and CD) are associated with changes in the levels of ILs and chemokines. The results of the sensitivity analyses were robust and no evidence of heterogeneity and horizontal pleiotropy was observed.ConclusionsThe present study showed that some ILs and chemokines affect IBD, but IBD and its main subtypes (UC and CD) have no effect on the level changes of ILs and chemokines.
Project description:BackgroundAcute pancreatitis (AP) is an extraintestinal manifestation of inflammatory bowel disease (IBD). Numerous observational studies have reported an increased risk of AP in patients diagnosed with IBD. However, the causal association and directionality between IBD or its subtypes and the development of AP remains unclear due to the limitations of observational research. This study aims to explore the relationship between IBD or its subtypes and AP risk using Mendelian Randomization (MR) method.MethodsA two-sample bidirectional MR study was conducted, selecting genetic variants associated with IBD and AP as instrumental variables from the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC) and FinnGen databases, respectively. The inverse-variance weighted (IVW) method used as the primary approach for causal inference. The Cochran Q test was employed for heterogeneity assessment. Sensitivity analyses were performed using the MR Egger intercept test, MR-Presso, and Leave-one-out method.ResultsThe results revealed that IBD (OR = 1.049, 95% CI = 1.010-1.090, p = 0.013) and ulcerative colitis (UC) (OR = 1.057, 95% CI = 1.013-1.102, p = 0.011) were significantly associated with an increased risk of AP. However, Crohn's disease (CD) (OR = 1.023, 95% CI = 0.993-1.055, p = 0.134) did not show a causal association with the risk of AP. Interestingly, AP was suggestively associated with a decreased risk of CD (OR = 0.797, 95% CI = 0.637-0.997, p = 0.047). Furthermore, there was no causal association between AP and the risk of IBD (OR = 0.886, 95% CI = 0.753-1.042, p = 0.144) or UC (OR = 0.947, 95% CI = 0.773-1.159, p = 0.595).ConclusionIn conclusion, this study provides genetic evidence supporting the causal influence of IBD (specifically UC) on AP, while CD does not appear to have a causal impact on AP.
Project description:Background: An association between inflammatory bowel disease (IBD) [which includes ulcerative colitis (UC) and Crohn's disease (CD)] and IgA nephropathy (IgAN) has been discovered in observational studies, but the causal relationship is still unknown. The aim of this study was to clarify the causal link between IBD (which includes UC and CD) and IgAN via a two-sample Mendelian randomization (MR) analysis. Methods: Eligible single-nucleotide polymorphisms (SNPs) were selected as instrumental variables (IVs) for analyses and were obtained from the publicly available genome-wide association study (GWAS) summary statistics. Inverse-variance weighting (IVW), Mendelian randomization-Egger (MR-Egger) regression, the Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) test, and the weighted median were utilized to obtain the results. The MR-PRESSO test and MR-Egger regression were also performed to detect and correct horizontal pleiotropy. The Cochran's Q test and "leave-one-out" analysis were also conducted to assess the stability and reliability of the MR results. Results: This study found that IBD, UC, and CD all had significant positive causal effects on IgAN risk (IBD: OR = 1.58, 95% CI 1.15-2.16, p = 4.53 × 10-3; UC: OR = 1.55, 95% CI 1.14-2.11, p = 4.88 × 10-3; CD: OR = 1.57, 95% CI 1.21-2.03, p = 5.97 × 10-4). No significant horizontal pleiotropic effect was found for the causal association between IBD, UC, CD, and the risk of IgAN. Cochran's Q test identified no evidence of heterogeneity for the IV estimates. The "leave-one-out" sensitivity analysis also revealed that the MR results were robust. Conclusion: The results of this two-sample MR analysis supported that IBD, UC, and CD were causally associated with the risk of IgAN, while there was no sufficient evidence for the causal effect of IgAN on IBD, UC, or CD. Our findings provide theoretical support and a new perspective for the diagnosis and treatment of these two diseases.
Project description:BackgroundEpidemiological studies have revealed a link between inflammatory bowel disease (IBD) and hidradenitis suppurativa (HS). To determine whether IBD and HS are causally related, we used the Mendelian randomization (MR) approach.MethodsA two-sample MR was performed using an analysis of 12,882 patients and 21,770 controls with IBD and its main subtypes, ulcerative colitis (UC) and Crohn's disease (CD). A total of 409 cases and 211,139 controls without hidradenitis suppurativa (HS) were included in the data for this condition from various GWAS investigations. Odds ratios (ORs) with 95% confidence intervals (CIs) are used to estimate causal effects.ResultsThe study assessed the causal relationship between HS and IBD in both directions. The risk of HS was increased by IBD (IVW OR = 1.34, 95% CI = 1.20-1.49, p = 2.15E-07) and, in addition, HS was affected by UC (IVW OR = 1.27, 95% CI = 1.13-1.43, p = 8.97E-04) and CD (IVW OR = 1.18, 95% CI = 1.08-1.29, p = 4.15E-04). However, there was no evidence of a causal relationship between HS and IBD or its subtypes (IBD IVW OR = 1.00, 95% CI = 0.96-1.05, p = 0.85; UC IVW OR = 0.99, 95% CI = 0.95-1.03, p = 0.65; CD IVW OR = 1.03, 95% CI = 0.98- 1.07, p = 0.28).ConclusionThis study demonstrates that IBD and its subtypes have a causal effect on HS, whereas HS does not affect IBD. Gut-skin axis interactions may help to understand this association. Nevertheless, further studies are needed to clarify the pathophysiology of the causal relationship between IBD and HS.
Project description:BackgroundAn epidemiological link between celiac disease (CeD) and inflammatory bowel disease (IBD) has been well established recently. In this study, Mendelian randomization (MR) analysis was performed employing pooled data of publicly available genome-wide association studies (GWAS) to determine the causal relationship between CeD and IBD, encompassing ulcerative colitis (UC) and Crohn's disease (CD).MethodsDataset of CeD was acquired from GWAS for 12,041 cases and 12,228 controls. A GWAS of more than 86,000 patients and controls was used to identify genetic variations underlying IBD. MR analyses were performed with an inverse-variance-weighted approach, an MR-Egger regression, a weighted-mode approach, a weighted-median method, and sensitivity analyses of MR pleiotropy residual sum and outlie (MR-PRESSO).ResultsMR demonstrated that genetic predisposition to CeD was linked to a augmented risk of IBD (OR: 1.1408; 95% CI: 1.0614-1.2261; P = 0.0003). In the analysis of the two IBD subtypes, genetic predisposition to CeD was also linked to increased risks of UC (OR: 1.1646; 95% CI: 1.0614-1.2779; P = 0.0012) and CD (OR: 1.1865; 95% CI: 1.0948-1.2859; P = 3.07E-05). Reverse MR analysis results revealed that genetic susceptibility to IBD and CD was correlated with an augmented risk of CeD. However, there was no genetic correlation between UC and CeD. All of the above results were validated with other GWAS databases.ConclusionThere is a bidirectional causal relationship of CeD with IBD and CD. However, UC only augments the risk of developing CeD.
Project description:AimUsing Mendelian Randomization (MR) analysis to investigate the potential causal association between Inflammatory Bowel Disease (IBD) and the occurrence of parenteral malignancies, in order to provide some reference for the parenteral malignancy prevention in patients with IBD.MethodsThis was a two-sample MR study based on independent genetic variants strongly linked to IBD selected from the Genome-Wide Association Study (GWAS) meta-analysis carried out by the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC). Parenteral malignancy cases and controls were obtained from the FinnGen consortium and the UK Biobank (UKB) release data. Inverse Variance Weighted (IVW), weighted median, MR-Egger, and strength test (F) were utilized to explore the causal association of IBD with parenteral malignancies. In addition, Cochran's Q statistic was performed to quantify the heterogeneity of Instrumental Variables (IVs).ResultsThe estimates of IVW showed that patients with IBD had higher odds of diffuse large B-cell lymphoma (OR = 1.2450, 95% CI: 1.0311‒1.5034). UC had potential causal associations with non-melanoma skin cancer (all p < 0.05), melanoma (OR = 1.0280, 95% CI: 0.9860‒1.0718), and skin cancer (OR = 1.0004, 95% CI: 1.0001‒1.0006). Also, having CD was associated with higher odds of non-melanoma skin cancer (all p < 0.05) and skin cancer (OR = 1.0287, 95% CI: 1.0022‒1.0559). In addition, results of pleiotropy and heterogeneity tests indicated these results are relatively robust.ConclusionsIBD has potential causal associations with diffuse large B-cell lymphoma and skin cancers, which may provide some information on the prevention of parenteral malignancies in patients with IBD. Moreover, further studies are needed to explore the specific mechanisms of the effect of IBD on skin cancers.
Project description:Objective: This Mendelian Randomization (MR) study aims to explore the potential bidirectional causal relationship between Inflammatory Bowel Disease (IBD) and Breast Cancer (BC). Materials and Methods: We utilized genetic instruments from the summary statistics of genome-wide association studies (GWAS) on IBD among individuals of European ancestry (12,882 cases and 21,770 controls) to investigate the association with breast cancer (14,910 cases and 17,588 controls) and vice versa. The primary causal estimates were obtained using the Inverse Variance Weighting Method (IVW), and the robustness of the results was evaluated through a series of sensitivity analyses. Results: The study found a positive impact of genetically predicted IBD on breast cancer (OR = 1.047; 95% CI:1.009-1.087; p = 0.014); in the analysis of IBD subtypes, genetically predicted Crohn's Disease (CD) also had a positive effect on breast cancer (OR = 1.044; 95% CI:1.015-1.073; p = 0.002), but genetically predicted Ulcerative Colitis (UC) did not show a significant effect on breast cancer (p > 0.05). The reverse Mendelian Randomization analysis indicated that genetically predicted breast cancer promoted the overall occurrence of IBD (OR = 1.112; 95% CI:1.022-1.211; p = 0.014); however, genetically predicted breast cancer did not show a significant correlation with IBD subtypes (CD and UC) (p > 0.05). Genetic predictions indicate a positive effect of Crohn's Disease (CD) on the risk of Estrogen Receptor-Positive Breast Cancer (ER + BC), with (OR = 1.021; 95% CI:1.002-1.040; p = 0.002). Furthermore, a reverse Mendelian randomization analysis reveals that genetically predicted ER + BC contributes to the increased incidence of ulcerative colitis (UC), as indicated by (OR = 1.098; 95% CI:1.032-1.168; p = 0.003). In contrast, genetically predicted Estrogen Receptor-Negative Breast Cancer (ER-BC) has been shown to promote the overall occurrence of inflammatory bowel disease (IBD), with (OR = 1.153; 95% CI:1.008-1.319; p = 0.037). However, bidirectional two-sample Mendelian randomization analyses between other pairs did not reveal any significant associations (p > 0.05). Conclusion: This study elucidates the bidirectional causal association between breast cancer and inflammatory bowel disease, highlighting the necessity of screening for IBD in breast cancer patients and for breast cancer in IBD patients in clinical settings.