Genome-Wide Association Study Identifies 4 Novel Risk Loci for Small Intestinal Neuroendocrine Tumors Including a Missense Mutation in LGR5.

BACKGROUND & AIMS: Small intestinal neuroendocrine tumor (SI-NET) is a rare disease, but its incidence has increased over the past 4 decades. Understanding the genetic risk factors underlying SI-NETs can help in disease prevention and may provide clinically beneficial markers for diagnosis. Here the results of the largest genome-wide association study of SI-NETs performed to date with 405 cases and 614,666 controls are reported. METHODS: Samples from 307 patients with SI-NETs and 287,137 controls in the FinnGen study were used for the identification of SI-NET risk-associated genetic variants. The results were also meta-analyzed with summary statistics from the UK Biobank (n = 98 patients with SI-NET and n = 327,529 controls). RESULTS: We identified 6 genome-wide significant (P < 5 × 10-8) loci associated with SI-NET risk, of which 4 (near SEMA6A, LGR5, CDKAL1, and FERMT2) are novel and 2 (near LTA4H-ELK and in KIF16B) have been reported previously. Interestingly, the top hit (rs200138614; P = 1.80 × 10-19) was a missense variant (p.Cys712Phe) in the LGR5 gene, a bona-fide marker of adult intestinal stem cells and a potentiator of canonical WNT signaling. The association was validated in an independent Finnish collection of 70 patients with SI-NETs, as well as in the UK Biobank exome sequence data (n = 92 cases and n = 392,814 controls). Overexpression of LGR5 p.Cys712Phe in intestinal organoids abolished the ability of R-Spondin1 to support organoid growth, indicating that the mutation perturbed R-Spondin-LGR5 signaling. CONCLUSIONS: Our study is the largest genome-wide association study to date on SI-NETs and reported 4 new associated genome-wide association study loci, including a novel missense mutation (rs200138614, p.Cys712Phe) in LGR5, a canonical marker of adult intestinal stem cells.

Identification of the VLDLR locus associated with giant cell arteritis and the possible causal role of low-density lipoprotein cholesterol in its pathogenesis.

OBJECTIVES: To elucidate the association between genetic variants and the risk of giant cell arteritis (GCA) via large-scale genome-wide association studies (GWAS). In addition, to assess the causal effect of a specific molecule by employing the obtained GWAS results as genetic epidemiological tools. METHODS: We applied additional variant quality control to the publicly available GWAS results from the biobank of the United Kingdom (UKBB) and Finnish (FinnGen), which comprised 532 cases vs 408 565 controls and 884 cases vs 332 115 controls, respectively. We further meta-analyzed these two sets of results. We performed two-sample Mendelian randomization (MR) to test the causal effect of low-density lipoprotein (LDL) cholesterol on the risk of GCA. RESULTS: The MHC class II region showed significant associations in UKBB, FinnGen, and the meta-analysis. The VLDLR region was associated with GCA risk in the meta-analysis. The T allele of rs7044155 increased the expression of VLDLR, decreased the LDL cholesterol level, and decreased the disease risk. The subsequent MR results indicated that a 1-standard deviation increase in LDL cholesterol was associated with an increased risk of GCA (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.01-1.45; p = 0.04). CONCLUSIONS: Our study identified associations between GCA risk and the MHC class II and VLDLR regions. Moreover, LDL cholesterol was suggested to have a causal effect on the risk of developing GCA.

Associations between genetically predicted concentrations of circulating inflammatory cytokines and the risk of ten pregnancy-related adverse outcomes: A two-sample Mendelian randomization study.

BACKGROUND: Evidence from increasing observational studies indicates that systemic inflammation plays a role in pregnancy-related adverse events. However, the causal associations between them are largely unclear. To investigate the potential causal effects of genetically regulated concentrations of inflammatory cytokines on the risk of adverse pregnancy outcomes, we performed a Mendelian randomization (MR) analysis. METHODS: The cis-protein quantitative trait loci for the 47 inflammatory cytokines derived from the latest genome-wide association studies (GWASs) consisting of 31,112 European individuals were used as the instrumental variables. The latest GWAS summary data for the ten adverse pregnancy events were obtained from the FinnGen project (samples ranging from 141,014 to 190,879). The inverse-variance weighted regression or Ward ratio was used as the primary MR analysis method. Sensitivity analyses based on the other five methods were performed to verify MR results. A replication MR analysis was conducted to further clarify the significant associations using data from the UK Biobank. RESULTS: Twenty-three of the 220 associations were nominally significant (P < 0.05). Among them, seven robust associations survived the Bonferroni correction and passed sensitivity analyses, including positive associations of soluble intercellular adhesion molecule (sICAM-1) with the risk of excessive vomiting in pregnancy, preeclampsia (PE), and pregnancy hypertension (PH), vascular endothelial growth factor with the risk of medical abortion, macrophage colony-stimulating factor (MCSF) with the risk of spontaneous abortion (SA), and an inverse association of macrophage inflammatory protein-1α with the risk of medical abortion. The associations of MCSF with SA, and sICAM-1 with both PE and PH were further confirmed in the replication analysis. CONCLUSIONS: This study provides further evidence of the role of systemic inflammation, especially endothelial dysfunction in the pathology of adverse pregnancy events, and the identified cytokines warrant in-depth research to explore their underlying mechanisms of action and to evaluate their potential as targets for disease screening, prevention, and treatment in the future.

Genetic susceptibility of urolithiasis: comprehensive results from genome-wide analysis.

BACKGROUND: The pathogenesis of urolithiasis is multi-factorial and genetic factors have been shown to play a significant role in the development of urolithiasis. We tried to apply genome-wide Mendelian randomization (MR) analysis and figure out reliable gene susceptibility of urolithiasis from the largest samples to date in two independent genome-wide association studies (GWAS) database of European ancestry. METHODS: We extracted summary statistics of expression quantitative trait locus (eQTL) from eQTLGen consortium. Urolithiasis phenotype information was obtained from both FinnGen Biobank and UK Biobank. Multiple two-sample MR analysis with a Bonferroni-corrected P threshold (P < 2.5e-06) was conducted. The primary endpoint was the causal effect calculated by random-effect inverse variance weighted (IVW) method. Sensitivity analysis, volcano plots, scatter plots, and regional plots were also performed and visualized. RESULTS: After multiple MR tests between 19942 eQTLs and urolithiasis phenotype from both cohorts, 30 common eQTLs with consistent effect size direction were found to be causally associated with urolithiasis risk. Finally only one gene (LMAN2) was simultaneously identified among all top significant eQTLs from both FinnGen Biobank (beta = 0.6758, se = 0.0327, P = 6.775e-95) and UK Biobank (beta = 0.0044, se = 0.0009, P = 2.417e-06). We also found that LMAN2 was with the largest beta effect size on urolithiasis phenotype from the two cohorts. CONCLUSION: We for the first time implemented genome-wide MR analysis to investigate the genetic susceptibility of urolithiasis in general population of European ancestry. Our results provided novel insights into common genetic variants of urinary stone disease, which was of great help to subsequent researches.

Association between leisure sedentary behaviors and hypertension risk: A prospective cohort study and two-sample Mendelian randomization analysis in Europeans.

OBJECTIVE: This study aimed to investigate the potential causal relationship between domain-specific sedentary behaviors (including television watching, computer use, and driving) and hypertension risk in European populations. METHODS: Initially, we conducted a multivariable Cox regression analysis to evaluate the associations between domain-specific sedentary behaviors and the risk of developing hypertension using data from 261,829 hypertension-free participants in the UK Biobank. To validate the findings of observational analysis, we employed two-sample univariable mendelian randomization (UVMR) analysis utilizing summary statistics from genome-wide association study conducted on European populations. We then performed multivariable mendelian randomization (MVMR) analysis to account for the influence of the risk factors for hypertension. RESULTS: In this prospective observational analysis, individuals who spent >3 h per day watching television had significantly higher risk of developing hypertension (HR = 1.24, 95% CI: 1.20-1.29, P < 0.001) compared to those who watched television for 0-1 h per day. The mendelian randomization analysis provided consistent evidence for a causal relationship between prolonged television watching time and hypertension risk (OR = 1.45, 95% CI: 1.25-1.69, P < 0.001; all PMVMR < 0.05) in both UVMR and MVMR results. No significant associations were found between computer use, driving behaviors and the risk of hypertension in either the observational or UVMR/MVMR analyses. CONCLUSIONS: These findings provide evidence for a causal effect specifically linking higher television watching time to an increased risk of hypertension and indicate the potential effectiveness of reducing television viewing time as a preventive measure to mitigate the risk of hypertension.

Exploring the mechanisms and relationship between body mass index and asthma: findings from Mendelian randomization.

BACKGROUND: The mechanism linking BMI and asthma remains unclear. METHOD: Mendelian Randomization (MR) analysis was conducted using summary-level GWAS data from the FinnGen Biobank and the Open GWAS project. The analysis considering potential variables as mediators, including blood cell counts, blood pressure, and blood biomarkers. Three commonly used MR methods-the inverse-variance-weighted (IVW) method, weighted median (WM) method, and MR-Egger method-were employed to infer causal links. A two-step approach was used in mediation analysis to evaluate the causal links among BMI, candidate mediators, and asthma. RESULT: Elevated BMI demonstrated a substantial correlation with increased asthma risk. Thirteen biomarkers mediated the relationship between BMI and asthma, mainly including leukocyte count (5.070%), apolipoprotein A levels (7.395%), cystatin C levels (5.345%), urate levels (9.057%), diastolic blood pressure (7.365%), and albumin levels (10.888%). These factors collectively explained over 50% of the increased asthma risk associated with BMI elevation. Additionally, eosinophil count and C-reactive protein were also identified as important mediators using the WM method. CONCLUSION: This study highlights the complex relationship between obesity, blood biomarkers, and asthma risk. Additional studies are required to validate these results and investigate causal relationships in various populations.

Strengthening the Evidence for a Causal Link between Type 2 Diabetes Mellitus and Pancreatic Cancer: Insights from Two-Sample and Multivariable Mendelian Randomization.

This two-sample Mendelian randomization (MR) study was conducted to investigate the causal associations between type 2 diabetes mellitus (T2DM) and the risk of pancreatic cancer (PaCa), as this causal relationship remains inconclusive in existing MR studies. The selection of instrumental variables for T2DM was based on two genome-wide association study (GWAS) meta-analyses from European cohorts. Summary-level data for PaCa were extracted from the FinnGen and UK Biobank databases. Inverse variance weighted (IVW) and four other robust methods were employed in our MR analysis. Various sensitivity analyses and multivariable MR approaches were also performed to enhance the robustness of our findings. In the IVW and Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) analyses, the odds ratios (ORs) for each 1-unit increase in genetically predicted log odds of T2DM were approximately 1.13 for PaCa. The sensitivity tests and multivariable MR supported the causal link between T2DM and PaCa without pleiotropic effects. Therefore, our analyses suggest a causal relationship between T2DM and PaCa, shedding light on the potential pathophysiological mechanisms of T2DM's impact on PaCa. This finding underscores the importance of T2DM prevention as a strategy to reduce the risk of PaCa.

Causal associations between gut microbiota and urological tumors: a two-sample mendelian randomization study.

BACKGROUND: Dysbiosis of gut microbiota has been linked to numerous diseases, including cancer. The unique role of gut microbiota in urological tumors is gaining prominence. However, it is still controversial whether the dysbiosis of gut microbiota should be one of the etiological factors of bladder cancer (BCa), prostate cancer (PCa) or kidney cancer (KCa). MATERIALS AND METHODS: The microbiome genome-wide association study (GWAS) from the MiBioGen consortium (18,340 samples of 24 population-based cohorts) was utilized as the exposure data. Additionally, outcomes data (951 BCa cases and 307,092 controls; 1,631 KCa cases and 238,678 controls; 79,148 PCa cases and 61,106 controls) were extracted from the GWAS of the FinnGen and PRACTICAL consortia. To detect the potential causative bacterial traits for BCa, PCa, and KCa, a two-sample Mendelian randomization (MR) analysis was performed, employing the inverse-variance weighted or Wald ratio method. Sensitivity analyses were subsequently conducted to explore the robustness of the primary results. Finally, the reverse MR analysis was undertaken to mitigate the reverse causation. RESULTS: This study suggested that Bifidobacterium (p = 0.030), Actinobacteria (p = 0.037 for phylum, 0.041 for class), and Ruminococcustorques group (p = 0.018), exhibited an association with an increased risk of BCa using either the inverse-variance weighted or Wald ratio method. By utilizing the Wald ratio method, Allisonella (p = 0.004, p = 0.038) was associated with a decreased risk of BCa and PCa, respectively. Furthermore, Ruminococcustorques group (p = 0.028) and Erysipelatoclostridium (p = 0.048) were causally linked to an elevated risk of KCa. CONCLUSIONS: This MR study supports that genetically predicted gut microbiota is causally related to BCa, PCa and KCa. Additionally, distinct bacterial traits are identified in relation to each tumor type.

Causal effect between gut microbiota and pancreatic cancer: a two-sample Mendelian randomization study.

BACKGROUND: Gut microbiota (GM) comprises a vast and diverse community of microorganisms, and recent studies have highlighted the crucial regulatory roles of various GM and their secreted metabolites in pancreatic cancer (PC). However, the causal relationship between GM and PC has yet to be confirmed. METHODS: In the present study, we used two-sample Mendelian randomization (MR) analysis to investigate the causal effect between GM and PC, with genome-wide association study (GWAS) from MiBioGen consortium as an exposure factor and PC GWAS data from FinnGen as an outcome factor. Inverse variance weighted (IVW) was used as the primary method for this study. RESULTS: At the genus level, we observed that Senegalimassilia (OR: 0.635, 95% CI: 0.403-0.998, P = 0.049) exhibited a protective effect against PC, while Odoribacter (OR:1.899, 95%CI:1.157-3.116, P = 0.011), Ruminiclostridium 9(OR:1.976,95%CI:1.128-3.461, P = 0.017), Ruminococcaceae (UCG011)(OR:1.433, 95%CI:1.072-1.916, P = 0.015), and Streptococcus(OR:1.712, 95%CI:1.071-1.736, P = 0.025) were identified as causative factors for PC. Additionally, sensitivity analysis, Cochran's Q test, the Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO), and MR-Egger regression indicated no heterogeneity, horizontal pleiotropy, or reverse causality between GM and PC. CONCLUSIONS: Our analysis establishes a causal effect between specific GM and PC, which may provide new insights into the potential pathogenic mechanisms of GM in PC and the assignment of effective therapeutic strategies.

Uniting biobank resources reveals novel genetic pathways modulating susceptibility for atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a common chronic inflammatory skin disease with high heritability. Previous genome-wide association studies have identified several loci predisposing to AD. These findings explain approximately 30% of the variance in AD susceptibility, suggesting that further work is required to fully understand the genetic underpinnings. OBJECTIVE: We sought to gain additional understanding of the genetic contribution to AD risk by using biobank resources. METHODS: We completed a genome-wide meta-analysis of AD in 796,661 individuals (Ncases = 22,474) from the FinnGen study, the Estonian Biobank, and the UK Biobank. We further performed downstream in silico analyses to characterize the risk variants at the novel loci. RESULTS: We report 30 loci associating with AD (P < 5 × 10-8), 5 of which are novel. In 2 of the novel loci, we identified missense mutations with deleterious predictions in desmocollin 1 and serpin family B member 7, genes encoding proteins crucial to epidermal strength and integrity. CONCLUSIONS: These findings elucidate novel genetic pathways involved in AD pathophysiology. The likely involvement of desmocollin 1 and serpin family B member 7 in AD pathogenesis may offer opportunities for the development of novel treatment strategies for AD in the future.

Genetic Susceptibility to Pneumonia: A GWAS Meta-Analysis Between the UK Biobank and FinnGen.

Pneumonia is a respiratory condition with complex etiology. Host genetic variation is thought to contribute to individual differences in susceptibility and symptom manifestation. Here, we analyze pneumonia data from the UK Biobank (14,780 cases and 439,096 controls) and FinnGen (9980 cases and 86,519 controls) and perform a genomewide association study meta-analysis. We use gene-based tests, colocalization, genetic correlation, latent causal variable (LCV) and polygenic prediction in an independent Australian sample (N = 5595) to draw insights into the etiology of pneumonia risk. We identify two independent loci on chromosome 15 (lead single-nucleotide polymorphisms rs2009746 and rs76474922) to be associated with pneumonia (p < 5e-8). Gene-based tests revealed 18 genes in chromosomes 15, 16 and 9, including IL127, PBX3, ApoB receptor (APOBR) and smoking related genes CHRNA3/5, statistically associated with pneumonia. We observed genetic correlations between pneumonia and cardiorespiratory, psychiatric and inflammatory related traits. LCV analysis suggests a strong genetic causal relationship with cardiovascular health phenotypes. Polygenic risk scores for pneumonia significantly predicted self-reported pneumonia in an independent sample, albeit with a small effect size (OR = 1.11 95% CI [1.04, 1.19], p < .05). Sensitivity analyses suggested the associations in chromosome 15 are mediated by smoking history, but the associations in chromosomes 16 and 9, and polygenic prediction were robust to adjustment for smoking. Altogether, our results highlight common genetic variants, genes and potential pathways that contribute to individual differences in susceptibility to pneumonia, and advance our understanding of the genetic factors underlying heterogeneity in respiratory medical outcomes.

Association between Type 1 Diabetes Mellitus and Parkinson's Disease: A Mendelian Randomization Study.

While much evidence suggests that type 2 diabetes mellitus increases the risk of Parkinson's disease (PD), the relationship between type 1 diabetes mellitus (T1DM) and PD is unclear. To study their association, we performed a two-sample Mendelian randomization (MR) using the following statistical methods: inverse variance weighting (IVW), MR-Egger, weight median, and weighted mode. Independent datasets with no sample overlap were retrieved from the IEU GWAS platform. All the MR methods found a lower risk of PD in T1DM (IVW-OR 0.93, 95% CI 0.91-0.96, p = 3.12 × 10-5; MR-Egger-OR 0.93, 95% CI 0.88-0.98, p = 1.45 × 10-2; weighted median-OR 0.93, 95% CI 0.89-0.98, p = 2.76 × 10-3; and weighted mode-OR 0.94, 95% CI 0.9-0.98, p = 1.58 × 10-2). The findings were then replicated with another independent GWAS dataset on T1DM (IVW-OR 0.97, 95% CI 0.95-0.99, p = 3.10 × 10-3; MR-Egger-OR 0.96, 95% CI 0.93-0.99, p = 1.08 × 10-2; weighted median-OR 0.97, 95% CI 0.94-0.99, p = 1.88 × 10-2; weighted mode-OR 0.97, 95% CI 0.94-0.99, p = 1.43 × 10-2). Thus, our study provides evidence that T1DM may have a protective effect on PD risk, though further studies are needed to clarify the underlying mechanisms.

Causal association between urine albumin-to-creatinine ratio and risk of colorectal cancer: A two-sample Mendelian randomization study.

Previous observational studies have investigated the association between urinary albumin excretion and the risk of colorectal cancer (CRC), but the results have been inconsistent. This study aimed to explore the causal association between urine albumin-to-creatinine ratio (ACR) and CRC risk through a two-sample Mendelian randomization (MR) analysis. The genome-wide association study (GWAS) data of ACR (n = 382,500) and CRC (CRC: 6,509 cases and 287,137 controls) were obtained from the IEU OpenGWAS project website and the FinnGen database, respectively. The TwoSampleMR and MR-PRESSO R packages were used to search for and analyze genetic variations that served as instrumental variables for ACR. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using the inverse-variance weighted method, MR-Egger, and weighted median. Genetically predicted ACR was not associated with CRC risk (all P > 0.05). Further analysis based on the site of onset (colon or rectum) also did not show a significant association (all P > 0.05). MR-PRESSO, MR-Egger regression and leave-one-out sensitivity analysis all indicated that the current results were robust and reliable. These findings suggest that ACR does not affect CRC risk and may not be used as a marker of CRC risk in clinical practice. However, relevant studies especially in ethnically diverse populations are still needed to confirm the current findings.

Association between frailty and gestational diabetes mellitus: a bidirectional and multivariable Mendelian randomization study.

Background: The causality between frailty and gestational diabetes mellitus (GDM) has not yet been fully explored. A potential bidirectional causality was also needed to be confirmed. Methods: A bidirectional two-sample Mendelian randomization (MR) was conducted, with frailty-related data was collected from UK Biobank and TwinGen and GDM-related data was collected from the FinnGen consortium. We performed univariable and multivariable-adjusted MR with adjustments for body mass index (BMI). Several methodologies of MR were conducted to confirm the robustness of results. Results: Frailty was significantly associated with elevated risks of GDM (OR, 3.563; 95% CI, 1.737 to 7.309; P< 0.001) and GDM was also significantly associated with elevated risks of frailty ( ß , 0.087; 95% CI, 0.040 to 0.133; P< 0.001). There is no evidence demonstrating the existence of horizontal pleiotropy and heterogeneity. This association was robust after adjustments for BMI. The sensitivity analyses with Weighted median, Maximum likelihood, Penalised weighted median, MR Egger and MR PRESSO methods indicated consistent results. Conclusion: Our study provides evidence of the bidirectional causal association between frailty and GDM from genetic perspectives, signaling that the identification and assessment of frailty should become a standard strategy during the early stages and care of gestational diabetes.

Endometriosis is a disease of immune dysfunction, which could be linked to microbiota.

Background: Endometriosis, characterized by extrauterine endometrial tissue, leads to irregular bleeding and pelvic pain. Menstrual retrograde theory suggests fragments traverse fallopian tubes, causing inflammation and scar tissue. Prevalent among infertile women, risk factors include fewer pregnancies, delayed childbirth, irregular cycles, and familial predisposition. Treatments, medication, and surgery entail side effects. Studies link gut microbiota alterations to endometriosis, necessitating research to establish causation. We used Mendelian randomization to investigate the potential link between endometriosis and gut microbiota through genetic variants. Methods: Two-sample Mendelian randomization analyzed gut microbiota's potential causal effects on endometriosis. Instrumental variables, robustly associated with exposures, leveraged GWAS data from MiBioGen for gut microbiota and FinnGen R8 release for endometriosis. SNPs strongly associated with exposures were instrumental variables. Rigorous assessments ensured SNP impact scrutiny on endometriosis. Results: At the genus level, Anaerotruncus, Desulfovibrio, Haemophilus, and Holdemania showed causal association with endometriosis. Specific gut microbiota exhibited causal effects on different endometriosis stages. Holdemania and Ruminococcaceae UCG002 exerted reversible, stage-specific impacts. Conclusion: Mendelian randomization provides evidence for the causal link between specific gut microbiotas and endometriosis, emphasizing the pivotal role of gut microbiota dysbiosis. Modulating gut microbiota emerges as a promising strategy for preventing and treating endometriosis.

Does metformin really reduce prostate cancer risk: an up-to-date comprehensive genome-wide analysis.

BACKGROUND: The relationship between metformin use and prostate cancer (PCa) risk has yet to be clear despite more than a decade of debate on this topic. Hence, we aimed to investigate the causal role of metformin in reducing PCa risk through an up-to-date comprehensive genome-wide analysis. METHODS: We employed validated instrument variables of metformin use derived from a prior high-quality study, including five potential targets (AMPK, GCG, GDF15, MCI and MG3). Mendelian randomization (MR) analysis was performed to harmonize genetically predicted metformin use and PCa phenotypes. PCa phenotypes were from two large genome-wide association studies (GWAS), the Prostate Cancer Association Group to Investigate Cancer-Associated Alterations in the Genome (PRACTICAL) and the FinnGen cohort. Seven methods were applied to generate MR results: the inverse variance weighted (IVW), IVW with multiplicative random effects, MR-Egger, MR-Egger (bootstrap), weighted median, simple mode and weighted mode. Strict sensitivity analysis was conducted to satisfy core assumptions of MR design. RESULTS: We enrolled 32 significant single nucleotide polymorphisms (SNPs) that involved with metformin use. Nearly all targets yielded insignificant primary results (IVW with multiplicative random effects), except that AMPK target posed a positive effect on PCa risk from FinnGen cohort [odds ratio (OR): 6.09, 95% confidence interval (CI): 1.10-33.53, P value: 0.038]. The general effect of metformin use, comprising all 5 targets, also yielded negative results (random-effect meta-analysis with OR: 1.09, 95% CI: 0.76-1.58, P value: 0.637 for PRACTICAL; OR: 2.55, 95% CI: 0.58-11.16, P value: 0.215 for FinnGen). None of the sensitivity analyses provided support for a causal association between metformin use and PCa risk. CONCLUSION: This up-to-date study did not support the protective role of metformin in reducing PCa risk, considering each target, overall effect, and sensitivity analysis. It is imperative to reflect on the presumed "almighty medicine" and ongoing phase III trials are anticipated to assess the anti-neoplasm effect of metformin.

Genetically predicted inflammatory proteins and the risk of atrial fibrillation: a bidirectional Mendelian randomization study.

Purpose: The causal associations between inflammatory factors and atrial fibrillation (AF) remained unclear. We aimed to investigate whether genetically predicted inflammatory proteins are related to the risk of AF, and vice versa. Methods: A bidirectional two-sample Mendelian randomization study was performed. The genetic variation of 91 inflammatory proteins were derived from genome-wide association study (GWAS) data of European ancestry (n = 14,824). Summary statistics for AF were obtained from a published meta-analysis study (n = 1,030,836) and the FinnGen study (n = 261,395). Results: Genetically predicted fibroblast growth factor 5 (FGF5) was significantly positively associated with risk of AF [[odds ratio (OR): 1.07; 95% CI: 1.04-1.10; P < 0.01], and CD40l receptor was significantly negatively associated with risk of AF (OR: 0.95; 95% CI: 0.92-0.98; P = 0.02) in the meta-analysis study. In the FinnGen study, similar results were observed in FGF5 (OR: 1.11; 95% CI: 1.06-1.16; P < 0.01) and CD40l receptor (OR: 0.93; 95% CI: 0.89-0.97; P = 0.03) for AF. In the FinnGen study, TNF-beta was significantly positively associated with risk of AF (OR: 1.05; 95% CI: 1.02-1.09; P = 0.03) and leukemia inhibitory factor receptor was significantly negatively associated with risk of AF (OR: 0.86; 95% CI: 0.80-0.91; P = 0.001). The causal effect of AF on inflammatory proteins was not observed. Conclusion: Our study suggested that FGF5 and CD40l receptor have a potential causal association with AF, and targeting these factors may help in the treatment of AF.

The causal relationship between gut microbiota and alopecia areata: a Mendelian randomization analysis.

Background: Increasing evidence suggests a robust correlation between the gut microbiome and alopecia areata. In light of the extensive diversity of gut microbiota, this study aims to utilize state-of-the-art and comprehensive data to explore the causative association between gut microbiota and alopecia areata. Objective: We conducted a Mendelian randomization (MR)-based two-sample study to elucidate the causal relationship between gut microbiota and alopecia areata. Method: Summary information on Ncase = 767 and Ncontrol = 394,105 cases of alopecia areata was obtained from the FinnGen study. A total of 473 gut microbial taxa were summarized from the genome-wide association study (GWAS) catalog. The study comprised a forward Mendelian randomization (MR) analysis with the gut microbiome as the exposure factor and alopecia areata as the outcome, as well as a reverse MR analysis with alopecia areata as the exposure factor and the gut microbiome as the outcome. Various analytical methods including inverse variance weighting (IVW), Weighted Median, MR-Egger, Weighted Mode, and Simple Mode were employed. Subsequently, sensitivity analysis was conducted to ensure the robustness of our research findings. Result: This study has established a causal relationship between gut microbiota and alopecia areata. Forward causal analysis revealed causality relationships between 16 gut microbial taxa and alopecia areata, while reverse causal analysis found that there may be a causal relationship between alopecia areata and 16 gut microbial taxa (not statistically significant). Conclusion: Our study findings suggest a causal relationship between gut microbiota and alopecia areata, providing potential guidance for future clinical trials.

Revealing the link between gut microbiota and brain tumor risk: a new perspective from Mendelian randomization.

Background: Recent studies have shown that gut microbiota may be related to the occurrence of brain tumors, but direct evidence is lacking. This study used the Mendelian randomization study (MR) method to explore the potential causal link between gut microbiota and brain tumors. Method: We analyzed the genome-wide association data between 211 gut microbiota taxa and brain tumors, using the largest existing gut microbiota Genome-Wide Association Studies meta-analysis data (n=13266) and combining it with brain tumor data in the IEU OpenGWAS database. We use inverse-variance weighted analysis, supplemented by methods such as Mendelian randomization-Egger regression, weighted median estimator, simple mode, and weighted mode, to assess causality. In addition, we also conducted the Mendelian randomization-Egger intercept test, Cochran's Q test, and Mendelian randomization Steiger directionality test to ensure the accuracy of the analysis. Quality control includes sensitivity analysis, horizontal gene pleiotropy test, heterogeneity test, and MR Steiger directionality test. Result: Our study found that specific gut microbial taxa, such as order Lactobacillales and family Clostridiaceae1, were positively correlated with the occurrence of brain tumors, while genus Defluviitaleaceae UCG011 and genus Flavonifractor were negatively correlated with the occurrence of brain tumors. The Mendelian randomization-Egger intercept test showed that our analysis was not affected by pleiotropy (P>0.05). Conclusion: This study reveals for the first time the potential causal relationship between gut microbiota and brain tumors, providing a new perspective for the prevention and treatment of early brain tumors. These findings may help develop new clinical intervention strategies and point the way for future research.

Causal associations between 45 dietary intake habits and urolithiasis: insights from genetic studies.

Background: Different dietary habits can have varying effects on human health and metabolism, and these can be intervened and regulated. Kidney stones, as a disease caused by multiple factors, are largely attributed to diet and metabolism, but the potential causal relationship with dietary intake habits remains unclear. Therefore, this study aims to link the predicted dietary intake based on 45 genetic factors with urolithiasis and explore the potential causal relationship. Methods: We extracted complete genome-wide association studies (GWASs) data on 45 dietary intake traits from the UK Biobank study. Data on kidney stones were obtained from the FinnGen database. In both univariable and multivariable Mendelian randomization analyses, we used inverse variance weighted (IVW) as the primary method to calculate P values, odds ratios (ORs), and 95% confidence intervals (CIs). We examined result heterogeneity using Cochran's Q test. We also carefully investigated potential sources of horizontal pleiotropy using the Mendelian randomization (MR)-PRESSO and MR-Egger methods, and conducted linkage disequilibrium score regression (LDSC) analysis on the corrected P values. Results: Through univariable analysis, we identified 11 dietary habits that potentially causally associate with kidney stones among the 45 examined traits, including 9 protective factors and 2 risk factors. Based on the corrected results with false discovery rate (FDR) and sensitivity analysis, we found one relatively robust evidence. We controlled for common stone risk factors, such as body mass index and smoking, as confounders in multivariable analysis, and no significant results were observed after controlling for these confounders. Based on the LDSC analysis, most of the evidence supports significant genetic correlations with urolithiasis among the 11 traits with potential causal associations. Conclusions: This study confirms the impact of certain dietary factors on the development of kidney stones. Our findings contribute to providing evidence for dietary adjustments in daily life or dietary guidance specifically targeting kidney stone patients.