Causal relationship between genetically predicted uterine leiomyoma and cancer risk: a two-sample Mendelian randomization.

Purpose: Studies have demonstrated that hormonal imbalance, such as elevated level of estrogen or reduced level of progesterone, was the main inducing factor of uterine leiomyoma (UL) development and some cancers. UL has been reported to be associated with several cancers in observational studies. However, the causal associations between UL and cancers remain unclear. Methods: A two-sample Mendelian randomization (MR) analysis was conducted to investigate the causal associations between UL and 16 site-specific cancers using the public databases. Four methods, namely, the inverse variance weighting (IVW), MR-Egger, weighted median, and weighted mode, were applied in our MR analysis. Sensitivity tests were also performed to evaluate the robustness of these causal associations. Results: The IVW analysis indicated that genetically predicted UL increased the risk of low malignant potential ovarian cancer [odds ratio (OR) = 1.22, 95% confidence interval (CI): 1.06-1.40, p = 0.004], serous ovarian cancer (OR = 1.29, 95% CI: 1.10-1.52, p = 0.002), invasive mucinous ovarian cancer (OR = 1.24, 95% CI: 1.08-1.44, p = 0.003), clear cell ovarian cancer (OR = 1.25, 95% CI: 1.03-1.51, p = 0.023), breast cancer (OR = 1.07, 95% CI: 1.02-1.11, p = 0.002), and brain tumor (OR = 1.23, 95% CI: 1.06-1.42, p = 0.007). Conversely, genetically predicted UL reduced the risk of gastric cancer (OR = 0.91, 95% CI: 0.85-0.98, p = 0.008). The causal effects were consistent in the sensitivity analysis. Conclusions: Our results demonstrated that UL exhibits a causal relationship with high risk of several cancers. We suggest reinforcing the cancer screening in UL patients to enable the early detection of cancers.

SLAMF1 as a novel molecule mediating the causal association between rheumatoid arthritis and interstitial lung disease: A Mendelian randomization study combined with transcriptomics and in vivo validation.

BACKGROUND: Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a common complication of rheumatoid arthritis (RA) that result in significant morbidity and mortality. Understanding the molecular mechanisms underlying RA-ILD is crucial for effective prevention. This study aims to identify the specific molecule that mediate the causal association between RA and ILD, as well as to explore its potential mechanisms in the pathogenesis of RA-ILD. METHODS: Using two-sample Mendelian randomization (MR) analyses, we investigated the causal relationship among 16,987 blood genes, RA and ILD. Subsequently, a two-step MR technique was employed to identify significant genes that mediate the association between RA and ILD, and to quantify their proportion of mediation effect. To validate the genes as mediators, the replication MR analysis was conducted and the in vivo experiment was performed using an established animal model of RA-ILD. Furthermore, integrated bioinformatic analyses were conducted to elucidate the specific biological functions of the determined mediator in pathogenesis of RA-ILD. RESULTS: Nine genes, namely MAPK8IP2, TAF11, SLAMF1, DAB2IP, GLUL, SLC4A10, PRSS35, NFX1, and PLK3, were identified as mediators. Among them, SLAMF1 was validated as the most significant mediator, accounting for 4.693% of the mediating effect on the causal relationship between RA and ILD. Upregulated mRNA expression of SLAMF1 was observed in the animal model of RA-ILD compared to controls. Bioinformatic analyses revealed that SLAMF1 was overexpressed in patients with lung fibrosis and correlated with a poor prognosis. Specifically, SLAMF1 was found to be predominantly overexpressed in T cells in lung tissues of patients with lung fibrosis. Additionally, the functional role of SLAMF1 was associated with multiple immune cell infiltrations and the biological process of extracellular matrix synthesis in pulmonary tissues from patients with lung fibrosis. CONCLUSION: SLAMF1 may play a crucial role as a molecular mediator in the causal association between RA and ILD, and participate in multiple mechanisms underlying the pathogenesis of RA-ILD. This research provides insights into how the development of RA influences the risk of ILD and offers potential interventional targets against RA-ILD.

Exposure to air pollution might decrease bone mineral density and increase the prevalence of osteoporosis: a Mendelian randomization study.

This study, using Mendelian randomization, reveals a causal link between nitrogen oxides and PM2.5 exposure and reduced total-body bone mineral density, highlighting a potential risk factor for osteoporosis. The findings emphasize the importance of targeted interventions in populations exposed to higher air pollution. INTRODUCTION: With the aging of the population, the prevalence of osteoporosis is escalating. Observational studies suggest that air pollution might diminish bone mineral density (BMD), contributing to elevating the likelihood of developing osteoporosis. METHODS: Employing a two-sample Mendelian randomization (MR) analysis, our study aimed to explore the potential causal effect of air pollution on total-body BMD. We utilized extensive publicly available data from genome-wide association studies (GWAS) in this research. Inverse variance weighting was selected for the primary effect estimation, complemented by additional approaches such as the weighted median, MR-Egger, simple mode, and weighted mode. Sensitivity analyses were then conducted to evaluate heterogeneity, pleiotropy, and the presence of outliers. RESULTS: In the MR analysis, our findings revealed causal associations between nitrogen oxides (ß = - 0.55, 95% CI - 0.90 to - 0.21, P = 0.002) and particulate matter (PM) 2.5 (ß = - 0.33, 95% CI - 0.59 to - 0.08, P = 0.010) and a reduction in total-body BMD. No significant associations were detected between PM2.5-10, PM10, nitrogen dioxide, and total-body BMD (P > 0.05). Rigorous sensitivity analyses verified the stability of these significant results. CONCLUSIONS: Our study illustrates that exposure to nitrogen oxides and PM2.5 may lead to a decrease in total-body BMD, increasing the risk of osteoporosis. This evidence holds crucial implications for policymakers and healthcare providers, as it can provide targeted interventions for the prevention of osteoporosis.

Unraveling the causative connection between urticaria, inflammatory cytokines, and mental disorders: Perspectives from genetic evidence.

BACKGROUND: The genetic association between urticaria and mental disorders and whether inflammatory cytokines mediate this process remains unclear. MATERIALS AND METHODS: A Mendelian randomization (MR) approaches to elucidate the causal relationship between urticaria and mental disorders and to validate the mediation of inflammatory cytokines. Genome-wide association study (GWAS) databases used were obtained from Psychiatric Genomics Cooperation (PGC), GWAS Catalog, and FinnGen Consortium. Our study was conducted using inverse variance weighted (IVW) and Bayesian weighted MR (BWMR) methods for joint analysis. RESULTS: The MR results showed that urticaria increased the risk of attention deficit hyperactivity disorder (ADHD) (odds ratio [OR] = $ = $ 1.088, 95% confidence interval [CI]: 1.026-1.154, p = $ = $ 0.0051); cholinergic urticaria increased the risk of bipolar disorder (BD) (OR = $ = $ 1.012, 95% CI: 1.001-1.022, p = $ = $ 0.0274); dermatographic urticaria increased the risk of ADHD (OR = $ = $ 1.057, 95% CI: 1.005-1.112, p = $ = $ 0.0323); idiopathic urticaria increased the risk of schizophrenia (SCZ) (OR = $ = $ 1.057, 95% CI: 1.005-1.112, p = $ = $ 0.0323); other unspecified urticaria increased the risk of ADHD (OR = $ = $ 1.085, 95% CI: 1.023-1.151, p = $ = $ 0.0063). We found that eight inflammatory cytokines were negatively associated with mental disorders and seven inflammatory cytokines were positively associated with mental disorders. Finally, our results suggested that inflammatory cytokines do not act as mediators between urticaria and mental disorders. CONCLUSIONS: Our study reveals a causal relationship between urticaria and the increased risk of mental disorders. We suggest that the treatment of urticaria could incorporate psychiatric interventions and mental health assessment of patients.

Causal associations between circulating immune cells and osteoarthritis: A bidirectional mendelian randomization study.

PURPOSE: Osteoarthritis (OA) is a common degenerative joint disease, with its etiology remaining poorly understood. Our study aims to explore the causal associations between immune cells and OA, with the goal of generating a new perspective for targeted intervention strategies. METHODS: A bidirectional two-sample Mendelian randomization (MR) analysis was performed to estimate the causality between multiple circulating immune cells and different sites of OA. The immune cell traits analyzed included the counts of circulating white blood cells (WBC), lymphocytes, monocytes, neutrophils, eosinophils, and basophils, as well as certain subsets of T and B lymphocytes. The OA types included were OA at any site, knee OA, hip OA, spine OA, thumb OA, and hand OA. Inverse-variance weighted (IVW), MR-Egger, weight median and weight mode were used to evaluate causal effects, with IVW being the main analysis method. Sensitivity analyses were conducted to assess heterogeneity and pleiotropy. RESULTS: Our findings indicated that resting regulatory T cell (Treg) absolute counts (AC) were causally associated with an increased risk for spine OA [odds ratio (OR), 1.051; 95 % confidence interval (CI), 1.018-1.086; P=0.0005, PFDR=0.0350], and spine OA showed a positive causal relationship with the neutrophils count (OR, 1.104; 95 %CI, 1.032-1.181; P=0.0039, PFDR=0.0233). Besides, OA at any site was correlated with a rise in circulating eosinophils count (OR, 1.05; 95 %CI, 1.021-1.079; P=0.0007, PFDR=0.0041), while knee OA was associated with decreased total WBC (OR, 0.945; 95 %CI, 0.912-0.979; P=0.0016, PFDR=0.0048) and monocytes counts (OR, 0.958; 95 %CI, 0.934-0.982; P=0.0007, PFDR = 0.0041). No evidence of heterogeneity or horizontal pleiotropy was detected. CONCLUSIONS: Our study has demonstrated the causal associations between multiple immune cells and diverse joint OA. These results highlight the intricate interplay between immune cells and OA, suggesting potential targets for therapeutic interventions to manage disease progression and alleviate symptoms.

Causal Association of Rheumatoid Arthritis With Adverse Pregnancy Outcomes: Genetic Evidence From Mendelian Randomization.

OBJECTIVE: Although the association of rheumatoid arthritis (RA) to multiple adverse pregnancy outcomes has been well-studied, the association between serum antibody levels in patients with RA and multiple adverse pregnancy outcomes has not been conclusively demonstrated. Here, we comprehensively assessed the causal impact of RA, serologic antibody-positive RA (pRA), and serologic antibody-negative RA (nRA) on the risk of 14 adverse pregnancy outcomes. METHODS: The causal impact of RA, pRA, and nRA on 14 adverse pregnancy outcomes was comprehensively assessed using two-sample Mendelian randomization (MR). Evidence maps based on the results of these two-sample MR analyses were developed. Data from the UK Biobank and FinnGen databases were utilized for this analysis. The inverse variance weighted (IVW) test was employed as the primary method to estimate causality. "TwoSampleMR" and "MR-PRESSO" packages were used for data analysis in this study. RESULTS: Using two-sample MR analysis, we found a significant positive causal association between RA and increased risk of cesarean section (p = 0.003), gestational hypertension (p < 0.001), number of spontaneous miscarriages (p = 0.041), preeclampsia (p = 0.008), premature rupture of membranes (p = 0.030), and preterm (p = 0.010). pRA had a significant positive causal association with an increased risk of cesarean section (p = 0.012), gestational hypertension (p < 0.001), preeclampsia (p = 0.002), and preterm (p = 0.007). A significant positive causal association was also established between nRA and gestational hypertension (p = 0.010), the number of spontaneous miscarriages (p = 0.024), and placental abruption (p = 0.027). In addition, we found a causal association between nRA and birth weight (p = 0.007), but not between RA and pRA and birth weight. CONCLUSION: The results of this study have important implications for the individualized treatment of RA patients, especially those with positive serum antibody levels.

Genetic liability to higher frailty index may increase the risk of ophthalmic disease.

PURPOSE: Frailty and age-related eye diseases are common in older people; however, whether there is a causal link remains unknown. We aimed to explore the causal associations between the frailty index (FI) and ophthalmic traits and identify modifiable mediators. METHODS: Linkage disequilibrium score regression and two-sample Mendelian randomization were applied to identify genetic correlations and causal associations between FI and ophthalmic traits. Summary data for FI was obtained from a genome-wide association study that included 175,226 individuals of European ancestry. Summary-level statistics for ophthalmic traits were obtained from relative GWASs. Summary-level data for cardiovascular risk factors, inflammatory biomarkers, and the central nervous system were used to identify the possible mediators. RESULTS: FI had a significant genetic correlation with 10 ophthalmic traits. Per SD increment of FI, the odds ratio was 1.329 (95% CI, 1.123, 1.573; P = 9.5 × 10-4) for cataracts, 1.825 (95% CI, 1.115, 2.986; P = 0.016) for keratitis, 1.798 (95% CI, 1.039, 3.11; P = 0.036) for disorders of vitreous body and 1.478 (95% CI, 1.005, 2.173; P = 0.046) for disorders of sclera, cornea, iris and ciliary body. The MR effect estimates of FI on ophthalmic traits were attenuated after adjusting for mental disorders, type 2 diabetes, triglyceride, and interleukin-8 (IL-8) levels. CONCLUSION: This study reports a genetic correlation and causal association between FI and ophthalmic traits, in which mental disorders, type 2 diabetes, triglycerides, and IL-8 may play a mediating role. These findings highlight a possible method to reduce the risk of FI-related ophthalmic diseases.

The causal association between epilepsy and amyotrophic lateral sclerosis: A two-sample Mendelian randomization study.

OBJECTIVES: Epilepsy and amyotrophic lateral sclerosis (ALS) are common neurological disorders. The association between the two disorders has been raised in observational studies. However, it is uncertain to what extent they have mutual causal effects. In this study, we aimed to investigate their causal association using a two-sample Mendelian randomization (MR) method. METHODS: We performed a two-sample bidirectional MR analysis to evaluate the causal association of epilepsy with the risk of ALS. Publicly published genome-wide association study statistics for epilepsy and ALS were used in the study. The primary analysis included genetic variants with a p value of less than 1 × 10-5 as instrumental variables. We applied several alternative methods, including inverse variance weighting, weighted median, simple mode, weighted mode, MR-Egger regression and MR pleiotropy residual sum and outlier, and statistical graphs to assess the associations of epilepsy and its subtype with the risk of ALS. Reverse MR analyses were also performed to examine the association of ALS with the risk of epilepsy. RESULTS: The primary MR analysis found no causal effect of epilepsy on risk of ALS (odds ration [OR]: 1.133, 95% confidence interval [CI]: 0.964-1.332, p = .130). Among subtypes of epilepsy, it also failed to observe any causal association between general epilepsy and ALS (OR: 1.036, 95% CI: 0.969-1.108, P = .300). However, focal epilepsy contributed to an increase in the risk of ALS (OR: 1.177, 95% CI: 1.027-1.348, p = .019). Moreover, the investigation of reverse causalities did not reveal significant results. CONCLUSIONS: The current study supports a causal influence of focal epilepsy on ALS risk. Future studies are needed to explore its potential role in ALS.

Circulating levels of vitamins and risk of lymphoma: insights from a two-sample Mendelian randomization.

BACKGROUND: To explore the genetic causal association between lymphoma and the circulating levels of vitamins through Mendelian randomization (MR). RESEARCH DESIGN AND METHODS: We performed MR analysis using publicly available genome-wide association study (GWAS) summary data. Seven indicators related to the circulating levels of vitamins (vitamin D, vitamin C, vitamin B6, vitamin B12, folic acid, vitamin E, and carotene) served as exposures, while lymphoma was the outcome. The genetic causal association between these circulating levels of vitamin indicators and lymphoma was assessed using the inverse variance weighted (IVW) method. RESULTS: Based on IVW method, vitamin B12 (OR = 0.48; 95% CI: 0.28-5.19; p = 0.018) and folic acid (OR = 0.62; 95% CI: 0.40-0.96; p = 0.032) both showed substantial evidence of a relationship with lymphoma. Moreover, the Weighted median method similarly indicated potential evidence of an association between vitamin B12 (OR = 0.40; 95% CI: 0.18-0.90; p = 0.027) and lymphoma. The Simple mode, and Weighted mode methods showed no potential genetic causal association (p > 0.05 in the two analyses). CONCLUSIONS: This study suggests a potential association between folic acid and vitamin B12 and lymphoma. Further research is required to assess the reproducibility of this finding in different contexts and to gain deeper insights into the potential underlying mechanisms.

Gut microbiota, allergic rhinitis, vasomotor rhinitis, Mendelian randomization, causal association.

OBJECTIVE: Continuous research on the structure and function of intestinal microecology has confirmed the association between gut microbiota and the occurrence, development, and outcome of allergic diseases. Here, we explored the genetic causality between gut microbiota and rhinitis. METHODS: We conducted a two-sample Mendelian Randomization (MR) study to investigate the genetic causal relationship between gut microbiota and allergic rhinitis and vasomotor rhinitis. Genetic variations in the human gut microbiota were obtained from the summary statistics of the MiBioGen study. Genome-wide summary statistics of rhinitis were obtained from the FinnGen consortium. The causal effect between gut microbiota and rhinitis was assessed using the inverse variance weighted, MR-Egger regression, and weighted median methods. In addition, sensitivity analyses were conducted using different methods, including maximum likelihood, simple mode, and weighted model methods. RESULTS: The IVW approach revealed a causal association of the genus Ruminococcus gauvreauii group with an increased risk of allergic rhinitis (IVW Odds Ratio [OR = 1.26] [1.04, 1.53], p-value = 0.01645). In addition, the genus Fusicatenibacter (IVW OR = 1.20 [1.02, 1.41], p-value = 0.02868) was causally associated with an increased risk of vasomotor rhinitis. CONCLUSION: Gut microbiota belonging to different genera exert different effects on allergic rhinitis and vasomotor rhinitis, including reducing the risk of rhinitis, and increasing the risk of rhinitis. New insights into the mechanisms of underlying gut microbiota-associated rhinitis are provided. LEVEL OF EVIDENCE: Level 5.

Causal associations between COVID-19 and erectile dysfunction: a Mendelian randomization study.

OBJECTIVE: In this study, we aimed to explore the potential association between COVID-19 infection, hospitalization, severe COVID-19, and erection dysfunction (ED) using the two-sample Mendelian randomization (MR) method. METHODS: Data pertaining to COVID-19 were extracted from the latest version of the COVID-19 Host Genetics Initiative genome-wide association study (GWAS) meta-analyses (Round 7, April 2022), and outcome data were obtained from the Open GWAS database. We applied various MR analysis methods, including the inverse variance weighted method, weighted median method, and MR-Egger regression. RESULTS: Our investigation revealed a negative causal association between COVID-19 hospitalization and ED (total testosterone levels: beta = -0.026; 95% confidence interval: -0.049 to -0.001). However, no evidence supported causal relationships between COVID-19 infection, hospitalization for COVID-19, or severe COVID-19 and other ED risk factors. CONCLUSION: The results of this comprehensive MR analysis suggest a negative causal link between COVID-19 hospitalization and total testosterone levels. Nonetheless, COVID-19 (comprising infection, hospitalization, and severe illness) may not directly correlate with an increased risk of ED. These findings imply that COVID-19 may exert a distinct impact on ED through indirect pathways.

Exploring the causal association between epigenetic clocks and menopause age: insights from a bidirectional Mendelian randomization study.

Background: Evidence suggests a connection between DNA methylation (DNAm) aging and reproductive aging. However, the causal relationship between DNAm and age at menopause remains uncertain. Methods: Employing established DNAm epigenetic clocks, such as DNAm Hannum age acceleration (Hannum), Intrinsic epigenetic age acceleration (IEAA), DNAm-estimated granulocyte proportions (Gran), DNAm GrimAge acceleration (GrimAgeAccel), DNAm PhenoAge acceleration (PhenoAgeAccel), and DNAm-estimated plasminogen activator inhibitor-1 levels (DNAmPAIadjAge), a bidirectional Mendelian randomization (MR) study was carried out to explore the potential causality between DNAm and menopausal age. The primary analytical method used was the inverse variance weighted (IVW) estimation model, supplemented by various other estimation techniques. Results: DNAm aging acceleration or deceleration, as indicated by Hannum, IEAA, Gran, GrimAgeAccel, PhenoAgeAccel, and DNAmPAIadjAge, did not exhibit a statistically significant causal effect on menopausal age according to forward MR analysis. However, there was a suggestive positive causal association between age at menopause and Gran (Beta = 0.0010; 95% confidence interval (CI): 0.0004, 0.0020) in reverse MR analysis. Conclusion: The observed increase in granulocyte DNAm levels in relation to menopausal age could potentially serve as a valuable indicator for evaluating the physiological status at the onset of menopause.

Causal role of immune cells in bipolar disorder: a Mendelian randomization study.

Background: The understanding of the immunological mechanisms underlying bipolar disorder (BD) has enhanced in recent years due to the extensive use of high-density genetic markers for genotyping and advancements in genome-wide association studies (GWAS). However, studies on the relationship between immune cells and the risk of BD remain limited, necessitating further investigation. Methods: Bidirectional two-sample Mendelian Randomization (MR) analysis was employed to investigate the causal association between immune cell morphologies and bipolar disorder. Immune cell traits were collected from a research cohort in Sardinia, whereas the GWAS summary statistics for BD were obtained from the Psychiatric Genomics Consortium. Sensitivity analyses were conducted, and the combination of MR-Egger and MR-Presso was used to assess horizontal pleiotropy. Cochran's Q test was employed to evaluate heterogeneity, and the results were adjusted for false discovery rate (FDR). Results: The study identified six immune cell phenotypes significantly associated with BD incidence (P< 0.01). These phenotypes include IgD- CD27- %lymphocyte, CD33br HLA DR+ CD14- AC, CD8 on CD28+ CD45RA+ CD8br, CD33br HLA DR+ AC, CD14 on CD14+ CD16+ monocyte, and HVEM on CD45RA- CD4+. After adjusting the FDR to 0.2, two immune cell phenotypes remained statistically significant: IgD-CD27-% lymphocyte (OR=1.099, 95% CI: 1.051-1.149, P = 3.51E-05, FDR=0.026) and CD33br HLA DR+ CD14-AC (OR=0.981, 95% CI: 0.971-0.991, P = 2.17E-04, FDR=0.079). In the reverse MR analysis, BD significantly impacted the phenotypes of four monocytes (P< 0.01), including CD64 on CD14+ CD16+ monocyte, CD64 on monocyte, CX3CR1 on CD14- CD16-, CD64 on CD14+ CD16- monocyte. However, after applying the FDR correction (FDR < 0.2), no statistically significant results were observed. Conclusions: This MR investigation reveals associations between immune cell phenotypes, bipolar disorder, and genetics, providing novel perspectives on prospective therapeutic targets for bipolar disorder.

Causal association between 731 immunocyte phenotypes and liver cirrhosis: A bidirectional two-sample mendelian randomization analysis.

BACKGROUND: Liver cirrhosis is a progressive hepatic disease whose immunological basis has attracted increasing attention. However, it remains unclear whether a concrete causal association exists between immunocyte phenotypes and liver cirrhosis. AIM: To explore the concrete causal relationships between immunocyte phenotypes and liver cirrhosis through a mendelian randomization (MR) study. METHODS: Data on 731 immunocyte phenotypes were obtained from genome-wide association studies. Liver cirrhosis data were derived from the Finn Gen dataset, which included 214403 individuals of European ancestry. We used inverse variable weighting as the primary analysis method to assess the causal relationship. Sensitivity analyses were conducted to evaluate heterogeneity and horizontal pleiotropy. RESULTS: The MR analysis demonstrated that 11 immune cell phenotypes have a positive association with liver cirrhosis [P < 0.05, odds ratio (OR) > 1] and that 9 immunocyte phenotypes were negatively correlated with liver cirrhosis (P < 0.05, OR < 1). Liver cirrhosis was positively linked to 9 immune cell phenotypes (P < 0.05, OR > 1) and negatively linked to 10 immune cell phenotypes (P < 0.05; OR < 1). None of these associations showed heterogeneity or horizontally pleiotropy (P > 0.05). CONCLUSION: This bidirectional two-sample MR study demonstrated a concrete causal association between immunocyte phenotypes and liver cirrhosis. These findings offer new directions for the treatment of liver cirrhosis.

Causal association between circulating inflammatory proteins and peripheral artery disease: a bidirectional two-sample Mendelian randomization study.

Introduction: A growing body of research has shown a strong connection between circulating inflammatory proteins and Peripheral artery disease (PAD). However, the causal relationship between circulating inflammatory proteins and PAD is still not fully understood. To investigate this association, we conducted a bidirectional Mendelian randomization study. Materials and methods: Our study utilized genetic variation data obtained from genome-wide association studies (GWAS) datasets. Specifically, the GWAS dataset related to PAD (identifier: finn-b-I9_PAD) included 7,098 cases and 206,541 controls. Additionally, we extracted data on 91 inflammatory proteins from another GWAS dataset (identifiers: GCST90274758-GCST90274848), involving 14,824 participants. To assess the causal relationship between circulating inflammatory proteins and PAD development, we employed methodologies such as inverse variance weighting (IVW), MR Egger regression, and the weighted median approach. Furthermore, sensitivity analyses were conducted to ensure the reliability and robustness of our findings. Results: Two inflammatory proteins were found to be significantly associated with PAD risk: Natural killer cell receptor 2B4 levels (OR, 1.219; 95% CI,1.019~1.457; P=0.03), Fractalkine levels (OR, 0.755; 95% CI=0.591~0.965; P=0.025). PAD had statistically significant effects on 12 inflammatory proteins: C-C motif chemokine 19 levels (OR, 0.714; 95% CI, 0.585 to 0.872; P=0.001), T-cell surface glycoprotein CD5 levels (OR, 0.818; 95% CI, 0.713 to 0.938; P=0.004), CUB domain-containing protein 1 levels (OR, 0.889; 95% CI, 0.809 to 0.977; P=0.015), Fibroblast growth factor 23 levels (OR, 1.129; 95% CI, 1.009 to 1.264; P=0.034), Interferon gamma levels (OR, 1.124; 95% CI, (1.011 to 1.250); P=0.031),Interleukin-15 receptor subunit alpha levels (OR, 1.183; 95% CI,(1.005 to 1.392); P=0.044), Interleukin-17C levels (OR,1.186; 95% CI, (1.048 to 1.342); P=0.007), Interleukin-1-alpha levels (OR, 1.349; 95% CI, (1.032 to 1.765); P=0.029), Interleukin-5 levels (OR, 1.119; 95% CI,(1.003 to 1.248); P=0.043), Latency-associated peptide transforming growth factor beta 1 levels (OR,1.123; 95% CI, (1.020 to 1.236); P=0.018), Matrix metalloproteinase-10 levels (OR, 1.119; 95% CI,(1.015 to 1.233); P=0.024), Signaling lymphocytic activation molecule levels (OR, 0.823; 95% CI, (0.693 to 0.978); P=0.027). Conclusion: Our research expands on genetic studies exploring the strong association between circulating inflammatory proteins and PAD. This discovery has the potential to inform and shape future clinical and basic research endeavors in this area.

Serum uric acid and pulmonary arterial hypertension: A two-sample Mendelian randomization study.

BACKGROUND: Observational studies have suggested a correlation between hyperuricemia and pulmonary arterial hypertension (PAH), yet the causal relationship remains uncertain. We aimed to establish this link using Mendelian Randomization (MR) methods. OBJECTIVES: Based on publicly accessible data, our study employs MR to determine the causal relationship between uric acid (UA) and PAH. METHOD: MR analysis was conducted among individuals of European descent. Genetic instruments linked to UA (p-value < 5 × 10-8) were extracted from the Chronic Kidney Disease Genetic Consortium and genome-wide association study databases. PAH risk genetic associations were sourced separately. We employed four MR methods (MR-Egger, weighted median, inverse variance weighted, and weighted mode) with selected instrumental variables to assess the causal association between UA and PAH. MR-PRESSO was used to evaluate pleiotropy and outlier Single Nucleotide Polymorphisms (SNPs), while Cochran's Q test and funnel plot assessed SNP heterogeneity. Leave-one-out analysis examined SNP impacts on causal assessment. RESULT: Two-sample MR analysis revealed a positive, causal relationship between UA levels and PAH. CONCLUSION: Our MR analysis provides robust evidence of a causal link between serum UA and PAH, suggesting UA's potential as a biomarker and therapeutic target for PAH.

Causal association between mental disorders and cerebrovascular diseases: Evidence from Mendelian randomization study.

BACKGROUND AND OBJECTIVE: Observational studies have suggested that mental disorders and cerebrovascular diseases (CVDs) may be risk factors for each other, but genetic evidence of a causal relationship is still lacking. We used Mendelian randomization (MR) studies to explore the causal relationship between mental disorders and CVDs from the genetic perspective. METHODS: To investigate the causal association between major depressive disorder (MDD), anxiety, attention deficit/hyperactivity disorder (ADHD), bipolar disorder and schizophrenia five kinds of mental disorders and CVDs using two-sample two-way MR analysis based on publicly available genome-wide association study (GWAS) data. We used as instrumental variables (IVs) single-nucleotide polymorphisms (SNPs) that were strongly associated with mental disorders and CVDs. IVW method was used as the main analysis method, and MR-IVW, MR-Egger methods, MR-PRESSO test, leave-one-out analysis and funnel plot were used for sensitivity analysis. We further conducted a meta-analysis to summarize the currently available MR analyses. RESULTS: The results of forward MR study showed that there was a significant causal relationship between ADHD and AS (any stroke) (p(AS) = 0.001, OR (95%CI) =1.118 (1.047-1.195)), any ischemic stroke (AIS) (p(AIS) = 0.004, OR (95%CI) =1.118(1.035-1.206)) and large artery stroke (LAS) (p(LAS) = 0.026, OR (95%CI): 1.206(1.023-1.422)). No heterogeneity, pleiotropy and outliers were found in sensitivity analysis. The reverse MR study showed that IA (intracranial aneurysm) (p(IA) = 0.033, OR (95%CI) = 1.123(1.009-1.249)) and UIA (unruptured intracranial aneurysm) (p(UIA) = 0.015, OR (95%CI) =1.040(1.008-1.074)) were risk factors for schizophrenia. Sensitivity analysis showed no pleiotropy, but there was heterogeneity. After excluding outliers, MR analysis showed that IA and UIA were still risk factors for schizophrenia. Our meta-analyses found statistical significance in causal relationships between ADHD and LAS (OR (95%CI) =1.18 (1.06-1.32), p = 0.003), IA and schizophrenia (OR (95%CI) =1.05 (1.02-1.08), p = 0.002) and UIA and schizophrenia (OR (95%CI) =1.03 (1.01-1.06), p = 0.010). CONCLUSION: The MR study and meta-analysis suggest that genetically predicted ADHD is a risk factor for LAS, and IA and UIA increase the risk of schizophrenia. The result has implications for the development of feasible prevention strategies in the future.

The impact of tea consumption on the risk of depression: A Mendelian randomization and Bayesian weighting algorithm study.

BACKGROUND AND OBJECTIVES: The precise impact of tea consumption on the risk of depression remains unclear. This study aimed to explore the relationship between the consumption patterns of tea and the likelihood of depression onset, utilizing a two-sample Mendelian randomization (MR) methodology. METHODS AND STUDY DESIGN: We utilized available genome-wide association study (GWAS) datasets on tea intake and depressive disorders. To investigate the causal relationship between tea consumption and depression, we employed a set of two-sample Mendelian Randomization (MR) methods. These included the inverse-variance weighted (IVW) analysis, weighted median approach, and MR-Egger regression. Additionally, we utilized MR-PRESSO and the MR-Egger intercept test for the detection of pleiotropic effects. To ensure the robustness and consistency of our findings, a sensitivity analysis was carried out, applying the 'leave-one-out' strategy. The Bayesian weighted Mendelian randomization (BWMR) was employed to conduct additional testing on the obtained results. RESULTS: The study's outcomes revealed a causal association between increased tea intake and an increased risk of depression (Inverse-Variance Weighted Analysis: Odds Ratio [OR] = 1.029, 95% Confidence Interval [CI]: 1.003-1.055, p = 0.027). This was observed despite variations in instrumental variables and the nonexistence of horizontal pleiotropy. Furthermore, the robustness of our Mendelian Randomization investigation was affirmed through the implementation of the 'leave-one-out' method in our sensitivity analysis. The findings from BWMR were in line with those obtained from IVW (BWMR: OR=1.030, 95% CI: 1.003-1.057, p = 0.029). CONCLUSIONS: The results from this study indicate a substantial and positive causal link between the regularity of tea drinking and the risk of depression onset.

Unraveling the impact of irritability on esophageal diseases: Insights from multivariable Mendelian randomization analysis.

BACKGROUND: Previous studies have suggested a potential association between irritability and the risk of various diseases. However, establishing a causal relationship has remained a significant challenge. To address this issue, we employed Mendelian randomization (MR), a sophisticated approach that leverages genotype data to emulate the conditions of randomized controlled trials. This method enables us to investigate the potential causal link between irritability and the susceptibility to esophageal diseases. METHODS: We conducted an extensive multivariable MR analysis using summary-level data from genome-wide association studies (GWAS) encompassing various esophageal diseases, including gastroesophageal reflux disease (GERD), esophageal cancer (EC), and Barrett's esophagus. Both univariable and multivariable MR analyses were performed to elucidate and confirm the causal association between genetically predicted irritability and the incidence of esophageal diseases. RESULTS: Based on our primary causal effects model utilizing MR analyses with the inverse-variance weighted (IVW) method, genetically predicted irritability was identified as a risk factor for GERD (OR = 2.413; 95 % CI: 1.678-3.470; P = 2.03E-06) and Barrett's esophagus (OR = 2.306; 95 % CI: 1.042-5.101; P = 0.039). However, irritability was not found to be associated with the risk of EC, even after adjusting for BMI, smoking initiation, and alcohol consumption. CONCLUSION: The multivariable MR analysis performed in this study demonstrated a causal relationship between irritability and esophageal diseases. It is imperative to acknowledge the need for further large-scale prospective studies to validate these findings.

Causality between migraine and cardiovascular disease: a bidirectional Mendelian randomization study.

BACKGROUND: While growing evidence suggests a relationship between migraine and cardiovascular disease, the genetic evidence for a causal relationship between migraine and cardiovascular disease is still scarce. Investigating the causal association between migraine and cardiovascular disease is vital. METHODS: We carried out a bidirectional Mendelian randomization (MR) study including discovery samples and replication samples using publicly available genome-wide association study (GWAS) summary datasets and stringent screening instrumental variables. Four different MR techniques-Inverse variance weighted (IVW), MR ‒Egger, weighted median, and weighted mode-as well as various sensitivity analyses-Cochran's Q, IVW radial, leave-one-out (LOO), and MR-PRESSO-were utilized to investigate the causal relationship between cardiovascular disease and migraine. RESULTS: The protective causal effects of genetically predicted migraine on coronary artery disease (OR, 0.881; 95% CI 0.790-0.982; p = 0.023) and ischemic stroke (OR, 0.912; 95% CI 0.854-0.974; p = 0.006) were detected in forward MR analysis but not in any other cardiovascular disease. Consistently, we also discovered protective causal effects of coronary atherosclerosis (OR, 0.865; 95% CI 0.797-0.940; p = 0.001) and myocardial infarction (OR, 0.798; 95% CI 0.668-0.952; p = 0.012) on migraine in reverse MR analysis. CONCLUSION: We found a potential protective effect of migraine on coronary artery disease and ischemic stroke and a potential protective effect of coronary atherosclerosis and myocardial infarction on migraine. We emphasised epidemiological and genetic differences and the need for long-term safety monitoring of migraine medications and future research to improve cardiovascular outcomes in migraine patients.