Mendelian Randomization Pleiotropy Residual Sum Research Articles

Exploring causal correlations between inflammatory cytokines and intervertebral disc degeneration: A Mendelian randomization.

Inflammatory cytokines have been reported to be related to intervertebral disc degeneration (IVDD) in several previous studies. However, it remains unclear about the causal relationship between inflammatory cytokines and IVDD. This study employs Mendelian randomization (MR) to analyze the causal link between inflammatory cytokines and the risk of IVDD. We used genetic variants associated with inflammatory cytokines from a meta-analysis of genome-wide association study (GWAS) in 8293 Finns as instrumental variables and IVDD data were sourced from the FinnGen consortium. The main analytical approach utilized Inverse-Variance Weighting (IVW) with random effects to assess the causal relationship. Additionally, complementary methods such as MR-Egger, weighted median, simple mode, weighted mode, and MR pleiotropy residual sum and outlier were employed to enhance the robustness of the final results. We found interferon-gamma (IFN-γ, p = 2.14 × 10-6, OR = 0.870, 95% CI = 0.821-0.921), interleukin-1 beta (IL-1b, p = 0.012, OR = 0.951, 95% CI = 0.914-0.989), interleukin-4 (IL-4, p = 0.034, OR = 0.946, 95% CI = 0.899-0.996), interleukin-18 (IL-18, p = 0.028, OR = 0.964, 95% CI = 0.934-0.996), granulocyte colony-stimulating factor (GCSF, p = 0.010, OR = 0.919, 95% CI = 0.861-0.980), and Stromal cell-derived factor 1a (SDF1a, p = 0.014, OR = 1.072, 95% CI = 1.014-1.134) were causally associated with risk of IVDD. Our MR analyses found a potential causal relationship between six inflammation cytokines (IFN-γ, IL-1b, IL-4, IL-18, SDF1a, and GCSF) and altered IVDD risk.

Female genital prolapse and risk of psychiatric disorders: A two-sample Mendelian randomization analysis.

There is a growing body of evidence suggests a strong link between female genital prolapse (FGP) and mental health. However, the causal relationship between FGP and psychological disorders remains unclear. Bidirectional Mendelian Randomization (MR) analysis has been applied to investigate the potential impact of FGP on the risk of seven common psychiatric disorders. The two-sample MR analysis was conducted using genetic instruments such as Inverse variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode from the genome-wide association study (GWAS) summary data in European populations. In addition, the Cochrane's Q test, MR-Egger intercept test, MR pleiotropy residual sum and outliers (MR-PRESSO) test and leave-one-out analysis were employed to assess the sensitivity and heterogeneity. The MR results revealed that FGP exhibited a potential marginal protective effect on bipolar disorder (BD) (odds ratio(OR) = 0.92, 95%confidence interval (95%CI: 0.85-0.99, P = 0.03) as well as schizophrenia(OR = 0.91, 95%CI:0.85-0.98, P = 0.01). Nevertheless, there was no causal correlation between genetically predicted FGP and obsessive compulsive disorder (OCD) (OR = 0.98, 95%CI:0.80-1.20, P = 0.84),depression (broad) (OR = 1.00, 95%CI:0.99-1.01, P = 0.76), major depression(OR = 0.98, 95%CI:0.94-1.03, P = 0.43), anxiety disorders (OR = 1.00, 95%CI:0.94-1.07,P = 0.97) and post-traumatic stress disorder(PTSD) (OR = 1.18, 95%CI:0.88-1.57,P = 0.27),respectively. In addition, BD was found to have a potential significant influence on FGP in the inverse MR analysis (OR = 0.83, 95%CI:0.72-0.97, P = 0.02). No significant heterogeneity or horizontal pleiotropy detected, and the results were deemed stable based on sensitivity analysis and leave-one-out test . There are shortcomings such as data limitations, population bias, potential pleiotropy, and stratified analysis. While there is potential causal relationship between FGP and BD or schizophrenia, it does not exhibit any correction with OCD, depression (broad), major depression, anxiety disorders and PTSD among European populations.

Causal associations between insulin and Lp(a) levels in Caucasian population:a Mendelian randomization study.

Numerous observational studies have demonstrated that circulating lipoprotein(a) [Lp(a)] might be inversely related to the risk of type 2 diabetes (T2D). However, recent Mendelian randomization (MR) studies do not consistently support this association. The results of in vitro research suggest that high insulin concentrations can suppress Lp(a) levels by affecting apolipoprotein(a) [apo(a)] synthesis. This study aimed to identify the relationship between genetically predicted insulin concentrations and Lp(a) levels, which may partly explain the associations between low Lp(a) levels and increased risk of T2D. Independent genetic variants strongly associated with fasting insulin levels were identified from meta-analyses of genome-wide association studies in European populations (GWASs) (N = 151,013). Summary level data for Lp(a) in the population of European ancestry were acquired from a GWAS in the UK Biobank (N = 361,194). The inverse-variance weighted (IVW) method approach was applied to perform two-sample summary-level MR. Robust methods for sensitivity analysis were utilized, such as MR‒Egger, the weighted median (WME) method, MR pleiotropy residual sum and outlier (MR-PRESSO), leave-one-out analysis, and MR Steiger. Genetically predicted fasting insulin levels were negatively associated with Lp(a) levels (β = -0.15, SE = 0.05, P = 0.003). The sensitivity analysis revealed that WME (β = -0.26, SE = 0.07, P = 0.0002), but not MR‒Egger (β = -0.22, SE = 0.13, P = 0.11), supported a causal relationship between genetically predisposed insulin levels and Lp(a). Our MR study provides robust evidence supporting the association between genetically predicted increased insulin concentrations and decreased concentrations of Lp(a). These findings suggest that hyperinsulinaemia, which typically accompanies T2D, can partially explain the inverse relationship between low Lp(a) concentrations and an increased risk of T2D.

Genetic Susceptibility of Thrombin Measurement Levels and the Risk of Colon Adenocarcinoma: A Mendelian Randomization Study.

Aims/Background: This investigation sought to establish a possible correlation between thrombin measurement levels and the risk of developing colon adenocarcinoma (COAD). Methods: Thrombin measurement levels were sourced from a study by Pietzner M (2020, PMID: 33328453) and integrated into the IEU database. Data on COAD were obtained from the FinnGen database (2021, C3_COLON_ADENO). Various analytical methods were used to assess the relationship, including inverse variance weighting (IVW), mendelian randomization-Egger (MR-Egger) regression, as well as weighted median and mode techniques. Sensitivity analyses were performed, including Cochran's Q test, MR-Egger intercept test, mendelian randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO), along with leave-one-out analysis, to ensure the robustness of the results. Results: The IVW analysis indicated a significant inverse association between elevated thrombin levels and the risk of COAD (odds ratio (OR) = 0.76, 95% CI = 0.66-0.88, p = 0.0003). These findings were supported by the weighted median analysis (OR = 0.78, 95% CI = 0.68-0.90, p = 0.0006) and the weighted mode analysis (OR = 0.78, 95% CI = 0.68-0.88, p = 0.0017). Conclusion: This research identified an inverse causal relationship between thrombin measurement levels and the incidence of COAD, suggesting that higher thrombin levels are associated with a reduced risk of developing COAD.

Association of serum uric acid with male sexual hormones and erectile dysfunction: a bidirectional 2-sample Mendelian randomization analysis.

Observational studies indicated that serum uric acid (SUA) was associated with male sexual hormones and erectile dysfunction (ED). However, their relationship was still heterogeneous. This study conducted 2-sample univariate mendelian randomization (UVMR) and multivariate mendelian randomization (MVMR) to explore the causal relationship between SUA and sexual hormones as well as ED. Genetic variants associated with SUA were derived from the UK Biobank database (N = 437 354). Outcomes from the IEU Open GWAS and summary data sets were sexual hormones (sex hormone-binding globulin [SHBG], testosterone, estradiol [E2], follicle-stimulating hormone, luteinizing hormone) and ED, with 3301 to 625 650 participants. UVMR analysis primarily utilized the inverse variance weighted method, complemented by MVMR analysis. Thorough sensitivity analyses were carried out to ensure the reliability of results. Moreover, mediation analysis was conducted to estimate the mediated effect between SUA and outcomes. The primary outcomes included results of UVMR and MVMR analysis and mediation analysis, along with sensitivity analyses involving the Cochran Q test, the MR Egger intercept test, leave-1-out analysis, and the MR-PRESSO method (mendelian randomization pleiotropy residual sum and outlier). UVMR analysis revealed that an elevated SUA level could decrease levels of SHBG (β = -0.10, P = 1.70 × 10-7) and testosterone (β = -0.10, P = 5.94 × 10-3) and had a positive causal effect on ED (odds ratio,1.10; P = .018). According to reverse mendelian randomization results, increased levels of SHBG (β = -0.06, P = 4.82 × 10-4) and E2 (β = -0.04, P = .037) could also reduce SUA levels. As shown by MVMR analysis, SUA had a negative effect on SHBG and testosterone levels (P <.05), while the significant causal relationship between SUA and ED disappeared. Furthermore, SHBG mediated 98.1% of the effect of SUA on testosterone levels. Results of other mendelian randomization analyses were not statistically significant. No pleiotropy was found by sensitivity analysis in this study. Given the causal relationship between SUA and sexual hormones, we must focus on SUA and E2 levels in men, especially patients with hypogonadism and ED. This study evaluated the causal effect of SUA on male sexual hormones and ED genetically for the first time, clarifying the common biases in observational studies and confirming the negative relationship between SUA and testosterone level. Limitations include a population based on European ancestry, some crossover of the samples, and unobserved confounding factors. Genetic studies provide evidence for the causal relationship between SUA and male sexual hormones (SHBG, testosterone, E2), while the relationship between SUA and ED should be further evaluated.

Causal Effects of Asthma on Upper Airway Diseases and Allergic Diseases: A Two-Sample Mendelian Randomization

Introduction: Asthma is associated with upper airway diseases and allergic diseases; however, the causal effects need to be investigated further. Thus, we performed this two-sample Mendelian randomization (MR) analysis to explore and measure the causal effects of asthma on allergic rhinitis (AR), vasomotor rhinitis (VMR), allergic conjunctivitis (AC), atopic dermatitis (AD), and allergic urticaria (AU). Methods: The data for asthma, AR, VMR, AC, AD, and AU were obtained from large-scale genome-wide association studies summarized recently. We defined single-nucleotide polymorphisms satisfying the MR assumptions as instrumental variables. Inverse-variance weighted (IVW) approach under random-effects was applied as the dominant method for causal estimation. The weighted median approach, MR-Egger regression analysis, MR pleiotropy residual sum and outlier test, and leave-one-out sensitivity analysis were performed as sensitivity analysis. Horizontal pleiotropy was measured using MR-Egger regression analysis. Significant causal effects were attempted for replication and meta-analysis. Results: We revealed that asthma had causal effects on AR (IVW, odds ratio [OR] = 1.93; 95% confidence interval [CI], 1.74−2.14; p < 0.001), VMR (IVW, OR = 1.40; 95% CI, 1.15−1.71; p < 0.001), AC (IVW, OR = 1.65; 95% CI, 1.49−1.82; p < 0.001), and AD (IVW, OR = 2.13; 95% CI, 1.82−2.49; p < 0.001). No causal effect of asthma on AU was observed. Sensitivity analysis further assured the robustness of these results. The evaluation of the replication stage and meta-analysis further confirmed the causal effect of asthma on AR (IVW OR = 1.81, 95% CI 1.62–2.02, p < 0.001), AC (IVW OR = 1.44, 95% CI 1.11–1.87, p < 0.001), and AD (IVW OR = 1.85, 95% CI 1.42–2.41, p < 0.001). Conclusions: We revealed and quantified the causal effects of asthma on AR, VMR, AC, and AD. These findings can provide powerful causal evidence of asthma on upper airway diseases and allergic diseases, suggesting that the treatment of asthma should be a preventive and therapeutic strategy for AR, VMR, AC, and AD.

A Mendelian randomization study on the relationship between insomnia and osteoporosis

Objective: To explore the relationship between insomnia and osteoporosis. Methods: Mendelian randomization (MR) analysis were used in this study. The single nucleotide polymorphisms (SNPs) related to insomnia from genome-wide association analysis research data were selected as the instrumental variables by using inverse variance weighted (IVW), MR-Egger regression, weighted median method, maximum likelihood, penalized weighted median estimator, and Mendelian randomization robust adjusted profile score (MR-RAPS) to determine the causal relationship between insomnia and osteoporosis. Odds ratio (OR) and 95% confidence interval (CI) values were used to evaluate the association between insomnia and osteoporosis. Cochran's Q-test was used to detect heterogeneity of SNPs, MR-Egger regression was used to test for level pleiotropy, and the leave-one-out method was used to test sensitivity, MR pleiotropy residual sum and outlier (MR-PRESSO) method and radial MR were used to detect erroneous outliers. Results: The screening criteria were set based on the three major assumptions of MR; finally, 31 SNPs were included in the MR analysis. The results of MR causal effect analysis using the IVW method showed that insomnia increased the risk of osteoporosis by about 0.7% (OR=1.007, 95%CI 1.001-1.014, P=0.044); heterogeneity testing showed heterogeneity between SNPs (Q=57.91, P<0.001); and the MR- Egger intercept test did not indicate horizontal pleiotropy in this study (intercept value=3.807×10-5, P=0.888). Leave-one-out method showed that no single SNP had a significant impact on the overall results. No abnormal SNP was detected according to the MR-PRESSO results (P=0.059), and radial MR did not detect any outliers. Conclusion: Mendelian randomization analysis showed that insomnia can increase the risk of osteoporosis.

Associations between Type 2 Diabetes Mellitus, Metabolic Traits, and Abdominal Aortic Aneurysm: A Cross-Ethnic Mendelian Randomization Analysis

Evidence suggests that type 2 diabetes mellitus (T2DM) may protect from abdominal aortic aneurysm (AAA). However, it is unclear whether a causal relationship exists between these 2 conditions and, if so, whether it remains consistent among racial groups. Cross-ethnic Mendelian randomization (MR) was used to examine the causal relationships between T2DM, metabolic traits, and AAA. Inverse variance weighted (IVW) was the primary analysis tool, supplemented by MR-Egger, weighted median, and MR Pleiotropy RESidual Sum and Outlier. Heterogeneity and horizontal pleiotropy were assessed using the Cochran's Q test and MR-Egger intercept, respectively. According to IVW, an inverse correlation between T2DM and AAA was detected in Europeans (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.84-0.99; P=0.034) and East Asians (OR 0.87, 95% CI 0.77-0.99; P=0.038). Fasting glucose was inversely associated with AAA in Europeans (OR 0.56, 95% CI 0.33-0.96; P=0.034) but not in East Asians. In Europeans, fasting insulin was a risk factor for AAA (OR 3.03, 95% CI 1.53-6.01; P=0.001), while 2-hour glucose was protective (OR 0.67, 95% CI 0.49-0.91; P=0.011). Glycated hemoglobin (HbA1c) had no effect. Insufficient instrumental variables prevented the evaluation of the relationships of fasting insulin, HbA1c, and 2-hour glucose with AAA in East Asians. T2DM protects against AAA in Europeans and East Asians. The effects of different glucose metabolism characteristics on AAA may inform AAA treatment.

Exploring causal correlations between blood inflammatory cytokines and low back pain: a Mendelian randomization

PurposeLow back pain (LBP) is a common and recurring public health problem that affects sufferers both physically and mentally and warrants further research. A succession of studies have suggested a plausible role for inflammatory cytokines in the pathogenesis of LBP. To date, there is no conclusive mechanism explaining how inflammatory cytokines affects LBP.MethodsA bidirectional two-sample Mendelian randomization (MR) investigation was undertaken in two stages. The initial phase encompassed 41 inflammatory cytokines as the exposure, with LBP as the outcome, and the subsequent phase adopted the inverse approach. A total of 41 blood inflammatory cytokines were extracted from the genome-wide association study meta-analysis database, encompassing 8,293 individuals. Data pertaining to LBP were acquired from the Finnish biobank. Primary findings were computed using inverse-variance weighting (IVW), while sensitivity analyses accounting for pleiotropy and invalid instruments were conducted utilizing the weighted-median estimator, MR-Egger, and MR Pleiotropy RESidual Sum and Outlier.ResultsOur results suggest that higher levels of Macrophage migration inhibitory factor (MIF) as well as lower levels of C-C motif chemokine ligand 3 (CCL3) are associated with an increased risk of LBP (odds ratio [OR] = 1.134, 95% confidence interval [CI ]= 1.032–1.245, P = 0.009; OR = 0.887, 95% CI = 0.803–0.980, P = 0.018). Moreover, there was no heterogeneity and horizontal pleiotropy observed in the sensitivity analysis. In contrast, in studies of the effect of LBP on inflammatory cytokines, genetically determined LBP had no causal effect on 41 inflammatory cytokines (IVW P > 0.05).ConclusionsOur study confirms that the levels of circulating MIF and CCL3 may be regarded as valuable circulating inflammatory biomarkers for the management of LBP in clinical practice and as potential molecules for future mechanistic investigation and drug target identification.

Absence of Causal Relationship Between Levels of Unsaturated Fatty Acids and ADHD: Evidence From Mendelian Randomization Study.

Previous research suggests a potential link between unsaturated fatty acids (UFAs) and ADHD, but the causal relationship remains uncertain. This study aims to investigate the causal association between ADHD and UFAs using Mendelian randomization (MR) analysis. Summary data from genome-wide association studies were used to estimate the concentration of circulating UFAs, including Monounsaturated Fatty Acids (MUFAs), Polyunsaturated Fatty Acids (PUFAs), Omega-3 PUFAs, Omega-6 PUFAs, Linoleic Acid (LA), and Docosahexaenoic Acid (DHA). Data from the Psychiatric Genomics Consortium, including both childhood and adult ADHD, were respectively used to examine the relationship between genetically predicted UFAs levels and ADHD. Various MR methods, including Inverse-variance weighted (IVW), MR Pleiotropy RESidual Sum and Outlier, MR-Egger, weighted median, and weighted mode, were employed to assess heterogeneity and pleiotropy. The IVW revealed only nominal evidence suggesting a potential causal relationship between genetically predicted PUFAs (OR = 0.92, 95% CI [0.85, 0.99], p = .031), Omega-6 PUFAs (OR = 0.90, 95% CI [0.83, 0.98], p = .020), and LA levels (OR = 0.90, 95% CI [0.82, 0.98], p = .021) with childhood ADHD risk. However, after false discovery rate correction, the p-values for PUFAs, Omega-6 PUFAs, and LA levels all exceeded the threshold for significance. For adult ADHD, we did not find any significant associations between the six circulating UFA levels and adult ADHD. Our findings do not support a causal relationship between UFAs levels and ADHD. This suggests that UFAs supplements may not be effective in improving ADHD symptoms and importantly, it appears that UFAs levels may not have a long-term effect on ADHD.

Rheumatoid arthritis and adverse pregnancy outcomes: a bidirectional two-sample mendelian randomization study

BackgroundThere is growing evidence of bidirectional associations between rheumatoid arthritis and adverse pregnancy outcomes (APOs) in observational studies, but little is known about the causal direction of these associations. Therefore, we explored the potential causal relationships between rheumatoid arthritis and APOs using a bidirectional two-sample Mendelian randomization (MR) in European and Asian populations.MethodsWe conducted a bidirectional two-sample Mendelian randomization analysis using available summary statistics from released genome-wide association studies. Summary statistics for instrument–outcome associations were retrieved from two separate databases for rheumatoid arthritis and adverse pregnancy outcomes, respectively. The inverse-variance weighted method was used as the primary MR analysis, and cML-MA-BIC was used as the supplementary analysis. MR-Egger, MR pleiotropy residual sum and outlier (MR-PRESSO), and Cochran Q statistic method were implemented as sensitivity analyses approach to ensure the robustness of the results.ResultsOur study showed that a higher risk of rheumatoid arthritis in the European population was associated with gestational hypertension (OR: 1.04, 95%CI: 1.02–1.06), pre-eclampsia (OR: 1.06, 95%CI: 1.01–1.11), fetal growth restriction (OR: 1.08, 95%CI: 1.04–1.12), preterm delivery (OR:1.04, 95%CI: 1.01–1.07). Furthermore, we found no evidence that APOs had causal effects on rheumatoid arthritis in the reverse MR analysis. No association between rheumatoid arthritis and APOs was found in East Asian population. There was no heterogeneity or horizontal pleiotropy.ConclusionsThis MR analysis provides the positive causal association from rheumatoid arthritis to gestational hypertension, pre-eclampsia, fetal growth restriction and preterm delivery genetically. It highlights the importance of more intensive prenatal care and early intervention among pregnant women with rheumatoid arthritis to prevent potential adverse obstetric outcomes.

Causal association between Neuroticism and risk of aortic aneurysm: A bidirectional two-sample Mendelian randomization study

BackgroundThe objective of this study was to analyze the causal relationship between Neuroticism and aortic aneurysm using Mendelian randomization (MR). The study aimed to establish a foundation for the development of effective prevention and treatment strategies. MethodsGenetic association data for Neuroticism were obtained from the UK Biobank, which included 393,411 individuals and 11,968,760 single nucleotide polymorphisms (SNPs). Genetic association data for aortic aneurysm were obtained from a genome-wide association study (GWAS), which included 479,194 individuals and 24,191,825 SNPs. Heterogeneity was assessed using the Cochran's Q statistic test. The study also utilized the MR Pleiotropy RESidual Sum and Outlier (Mr-PRESSO) test, as well as the MR-Egger regression method, to examine horizontal pleiotropy and determine the reliability of the findings through the leave-one-out method. ResultsForward MR analysis showed that the risk of aortic aneurysm was elevated in individuals with genetically predicted Neuroticism compared to those without Neuroticism (OR = 1.1315, 95 % CI: 1.0269–1.2468; P = 0.0126). The Cochran's Q test showed no heterogeneity (P > 0.05), and the MR-PRESSO test did not identify instrumental variables of horizontal pleiotropy (P > 0.05). The MR analysis remained robust after removing SNPs one by one. Inverse MR analysis did not observe an association between aortic aneurysm and having Neuroticism OR = 1.030, 95 % CI: 0.9459–1.118, P = 0.488). ConclusionOur study has established a clear causal relationship between genetically determined Neuroticism and the development of aortic aneurysms. It is therefore important to intensify screening and prevention efforts for aortic aneurysms in neurotic patients. It also opens new avenues for exploring the disease's pathogenesis.

Effect of caffeine intake on self-reported and genetic prediction of osteoarthritis: an epidemiological study and Mendelian randomization analysis.

Osteoarthritis (OA) holds the distinction of being the most widespread musculoskeletal disorder. Any disruptions in the integrity of the articular cartilage can result in joint malfunction, discomfort, and impaired physical functioning. Increasing evidence indicates the negative impacts of caffeine intake on hyaline cartilage. The primary objective of this study was to delve deeper into understanding the potential link between the consumption of caffeine and the risk of developing OA. In this study, we constructed logistic regression models to evaluate the correlation between caffeine consumption and the risk of osteoarthritis using data from the National Health and Nutrition Examination Survey. Following that, we utilized genome-wide association studies to conduct a Mendelian randomization (MR) analysis investigating the association between coffee consumption and the likelihood of developing knee OA. We employed various statistical methods, including inverse variance weighting (IVW), weighted median, weighted mode, simple mode, and MR-Egger regression, to ensure comprehensive analysis and robust conclusions. To evaluate heterogeneity and the potential impact of pleiotropy, we conducted several statistical tests, including Cochran's Q test, MR-Egger intercept test, MR Pleiotropy RESidual Sum and Outlier test (MR-PRESSO), and MR Steiger test. The weighted multivariate logistic regression analysis showed that the relationship between high caffeine intake (95-206 and ≥206 mg/day) and OA prevalence remained significantly high even after adjusting for covariates using the lowest caffeine intake (< 11 mg/day) as reference: Model 1-OR (95% Cl) = 1.365 (1.18-1.58) and 1.59 (1.38-1.83); Model 2-OR (95% Cl) = 1.21 (1.04-1.42) and 1.44 (1.23-1.68); and Model 3-OR (95% Cl) = 1.19 (1.01-1.40) and 1.30 (1.10-1.52), respectively (p < 0.05). The findings from the fixed effects inverse variance weighted (IVW) analysis revealed a statistically significant link between coffee intake and the likelihood of developing knee osteoarthritis: OR = 1.94; 95% confidence interval (Cl) =1.471-2.517; (p < 0.001). Consistent findings were obtained across various other methods, including MR-Egger regression, weighted median, weighted mode, and simple mode analyses. Our study showed a positive correlation between OA prevalence and high caffeine intake (≥95 mg/day).

The genetic relationship between hypotension and delirium: a Mendelian randomization study.

Observational research suggests that hypotension is a potential hazard factor of delirium. Nevertheless, previous observational articles are limited in their ability to establish causality between hypotension and delirium. The present study was sought to explore the genetic causal relationship between these two conditions using two-sample Mendelian randomization (MR). Genome-wide association study (GWAS) summarized data for hypotension and delirium were obtained from the FinnGen Consortium. The researchers utilized several statistical methods, such as inverse-variance weighted (IVW), weighted median, MR Egger, weighted mode, and simple mode in conducting the MR statistical analysis. In order to identify heterogeneity among the MR outcomes, we employed the Cochrane's Q test. Furthermore, we used the MR-Egger intercept test and MR pleiotropy residual sum and outliers (MR-PRESSO) test to examine horizontal pleiotropy. The findings revealed that hypotension was identified as an independent hazard variable for delirium (p = 0.010, odds ratio [OR] [95% confidence interval (CI)] = 1.302 [1.066-1.592]) using the IVW method. The presence of horizontal pleiotropy was found to have minimal impact on establishing causal relationship (p = 0.999), and there was no evidence to suggest heterogeneity between genetic variations (p = 0.379). Additionally, the leave-one-out method demonstrated the stability and robustness of this association. We performed two-sample MR analyses and found evidence of a genetic causal relationship between hypotension and delirium. Our findings suggest that individuals with a genetic predisposition for hypotension may have a higher risk of developing delirium. This suggests that interventions aimed at improving perioperative hypotension could aid in limiting the incidence of delirium.

Diet affects inflammatory arthritis: a Mendelian randomization study of 30 dietary patterns causally associated with inflammatory arthritis.

The causal associations between dietary intake and the risk and severity of Inflammatory Arthritis (IA) are currently unknown. In this study, we aimed to investigate the causal relationship between nine dietary categories (30 types of diet) and IA using Mendelian randomization (MR). We analyzed data from 30 diets and IA in a genome-wide association study (GWAS). Single nucleotide polymorphisms (SNPs) that could influence the results of MR analyses were screened out through the Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test. SNPs were analyzed through two-sample bidirectional MR using inverse variance weighting, MR-Egger regression, and weighted median method. The multiplicity and heterogeneity of SNPs were assessed using MR-Egger intercept term tests and Cochran's Q tests. FDR correction was used to correct the p-values. IVW results showed that Beef intake [Odds ratio (OR) = 2.862; 95% confidence interval (CI), 1.360-6.021, p = 0.006, p_fdr < 0.05] was positively associated with rheumatoid arthritis(RA); Dried fruit intake (OR = 0.522; 95% CI, 0.349-0.781, p = 0.002, p_fdr < 0.05), and Iron intake (OR = 0.864; 95%CI, 0.777-0.960, p = 0.007, p_fdr < 0.05) were negatively associated with RA, all of which were evidence of significance. Fresh fruit intake (OR = 2.528. 95% CI, 1.063-6.011, p = 0.036, p_fdr > 0.05) was positively associated with psoriatic arthritis (PsA); Cheese intake (OR = 0.579; 95% CI, 0.367-0.914, p = 0.019, p_fdr > 0.05) was negatively associated with PsA; both were suggestive evidence. Processed meat intake (OR = 0.238; 95% CI, 0.100-0.565, p = 0.001, p_fdr < 0.05) was negatively associated with reactive arthritis (ReA), a protective factor, and significant evidence. All exposure data passed the heterogeneity check (Cochrane's Q test p > 0.05) and no directional pleiotropy was detected. Leave-one-out analyses demonstrated the robustness of the causal relationship in the positive results. Our study presents genetic evidence supporting a causal relationship between diet and an increased risk of IA. It also identifies a causal relationship between various dietary modalities and different types of IA. These findings have significant implications for the prevention and management of IA through dietary modifications.

Causal relationship between inflammatory markers and left ventricle geometry and function: A 2-sample Mendelian randomization study.

Studies have shown that some inflammatory markers can predict the risk of cardiovascular disease (CVD) and affect the structure and function of the heart. However, a causal relationship between inflammatory markers and the cardiac structure and function has not yet been established. Thus, we conducted a 2-sample Mendelian randomization (MR) study to explore the potential causal relationship between inflammatory markers and prognostically-related left ventricular (LV) parameters. Instrumental variables (IVs) for C-reactive protein (CRP), interleukin-6 (IL-6), and myeloperoxidase (MPO) levels were selected from the databases of large genome-wide association studies (GWAS). Summary statistics for LV parameters, including LV mass, ejection fraction, end-diastolic and systolic volumes, and the ratio of LV mass to end-diastolic volume, were obtained from cardiovascular magnetic resonance studies of the UK Biobank (n = 16923). The inverse-variance weighted (IVW) method was the primary analytical method used, and was complemented with the MR-Egger, weighted median, simple mode, weighted mode, and MR pleiotropy residual sum and outlier (MR-PRESSO) methods. Sensitivity analysis was performed to evaluate the robustness of the results. CRP was significantly associated with the LV mass in the IVW method (β = -0.13 g [95% confidence interval [CI], 0.78 g-1.00 g], P = .046). A higher standard deviation of genetically-predicted CRP levels was associated with a 0.13 ± 0.06 g lower LV mass. No causal relationships of IL-6 and MPO with LV parameters were found. No evidence of heterogeneity and pleiotropy was detected. Sensitivity analyses confirmed the robustness of the results. Two-sample MR analysis revealed a causal association between increased CRP level and decreased LV mass, whereas IL-6 and MPO levels did not influence the LV parameters. However, further research is required to validate our findings.

Genetic evidence for causal association between migraine and dementia: a mendelian randomization study

BackgroundThere is an association between migraine and dementia, however, their causal relationship remains unclear. This study employed bidirectional two-sample Mendelian randomization (MR) to investigate the potential causal relationship between migraine and dementia and its subtypes: Alzheimer’s disease (AD), vascular dementia (VaD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB).MethodsSummary-level statistics data were obtained from publicly available genome-wide association studies (GWAS) for both migraine and five types of dementia. Single nucleotide polymorphisms (SNPs) associated with migraine and each dementia subtype were selected. MR analysis was conducted using inverse variance weighting (IVW) and weighted median (WM) methods. Sensitivity analyses included Cochran’s Q test, MR pleiotropy residual sum and outlier (MR-PRESSO) analysis, the intercept of MR-Egger, and leave-one-out analysis.ResultsMigraine showed a significant causal relationship with AD and VaD, whereas no causal relationship was observed with all-cause dementia, FTD, or DLB. Migraine may be a potential risk factor for AD (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 0.02–0.14; P = 0.007), while VaD may be a potential risk factor for migraine (OR: 1.04; 95% CI: 0.02–0.06; P = 7.760E-5). Sensitivity analyses demonstrated the robustness of our findings.ConclusionOur study suggest that migraine may have potential causal relationships with AD and VaD. Migraine may be a risk factor for AD, and VaD may be a risk factor for migraine. Our study contributes to unraveling the comprehensive genetic associations between migraine and various types of dementia, and our findings will enhance the academic understanding of the comorbidity between migraine and dementia.

Causal relationship between bone mineral density and intervertebral disc degeneration: a univariate and multivariable mendelian randomization study

BackgroundAlthough previous studies have suggested a possible association between bone mineral density (BMD) and intervertebral disc degeneration (IDD), the causal relationship between them remains unclear. Evidence from accumulating studies indicates that they might mutually influence one another. However, observational studies may be affected by potential confounders. Meanwhile, Mendelian randomization (MR) study can overcome these confounders to assess causality.ObjectivesThis Mendelian randomization (MR) study aimed to explore the causal effect of bone mineral density (BMD) on intervertebral disc degeneration (IDD).MethodsSummary data from genome-wide association studies of bone mineral density (BMD) and IDD (the FinnGen biobank) have been acquired. The inverse variance weighted (IVW) method was utilized as the primary MR analysis approach. Weighted median, MR-Egger regression, weighted mode, and simple mode were used as supplements. The Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) and MR-Egger regression were performed to assess horizontal pleiotropy. Cochran’s Q test evaluated heterogeneity. Leave-one-out sensitivity analysis was further conducted to determine the reliability of the causal relationship. Multivariate MR (MVMR) analyses used multivariable inverse variance-weighted methods to individually and jointly adjust for four potential confounders, body mass index (BMI), Type2 diabetes, hyperthyroidism and smoking. A reverse MR analysis was conducted to assess potential reverse causation.ResultsIn the univariate MR analysis, femoral neck bone mineral density (FNBMD), heel bone mineral density (eBMD), lumbar spine bone mineral density (LSBMD), and total body bone mineral density (TB BMD) had a direct causal effect on intervertebral disc degeneration (IDD) [FNBMD-related analysis: OR(95%CI) = 1.17 (1.04 to 1.31), p = 0.008, eBMD-related analysis: OR(95%CI) = 1.06 (1.01 to 1.12), p = 0.028, LSBMD-related analysis: OR(95%CI) = 1.20 (1.10 to 1.31), p = 3.38E-7,TB BMD-related analysis: OR(95%CI) = 1.20 (1.12 to 1.29), p = 1.0E-8]. In the MVMR analysis, it was revealed that, even after controlling for confounding factors, heel bone mineral density (eBMD), lumbar spine bone mineral density (LSBMD), and total body bone mineral density (TB BMD) still maintained an independent and significant causal association with IDD(Adjusting for heel bone mineral density: beta = 0.073, OR95% CI = 1.08(1.02 to 1.14), P = 0.013; Adjusting for lumbar spine bone mineral density: beta = 0.11, OR(95%CI) = 1.12(1.02 to 1.23), P = 0.03; Adjusting for total body bone mineral density: beta = 0.139, OR95% CI = 1.15(1.06 to 1.24), P = 5.53E − 5). In the reverse analysis, no evidence was found to suggest that IDD has an impact on BMD.ConclusionsThe findings from our univariate and multivariable Mendelian randomization analysis establish a substantial positive causal association between BMD and IDD, indicating that higher bone mineral density may be a significant risk factor for intervertebral disc degeneration. Notably, no causal effect of IDD on these four measures of bone mineral density was observed. Further research is required to elucidate the underlying mechanisms governing this causal relationship.

Exploring the bidirectional causal associations between pain and circulating inflammatory proteins: A Mendelian randomization study.

Multisite chronic pain (MCP) and site-specific chronic pain (SSCP) may be influenced by circulating inflammatory proteins, but the causal relationship remains unknown. To overcome this limitation, two-sample bidirectional Mendelian randomization (MR) analysis was used to analyse data for 91 circulating inflammatory proteins, MCP and SSCP encompassing headache, back pain, shoulder pain, hip pain, knee pain, stomach abdominal pain and facial pain. The primary MR method used was inverse variance weighting, sensitivity analyses included weighted median, MR pleiotropy residual sum and outlier and the Egger intercept method. Heterogeneity was also detected using Cochrane's Q test and leave-one-out analyses. Finally, a causal relationship between 29 circulating inflammatory proteins and chronic pain was identified. Among these proteins, 14 exhibited a protective effect, including MCP (T-cell surface glycoprotein cluster of differentiation 5), headache (4E-binding protein 1 [4EBP1], cluster of differentiation 40, cluster of differentiation 6 and C-X-C motif chemokine [CXCL] 11), back pain (leukaemia inhibitory factor), shoulder pain (fibroblast growth factor [FGF]-5 and interleukin [IL]-18R1), stomach abdominal pain (tumour necrosis factor [TNF]-α), hip pain (CXCL1, IL-20 and signalling lymphocytic activation molecule 1) and knee pain (IL-7 and TNF-β). Additionally, 15 proteins were identified as risk factors for MCP and SSCP: MCP (colony-stimulating factor 1, human glial cell line-derived neurotrophic factor and IL-17C), headache (fms-related tyrosine kinase 3 ligand, IL-20 receptor subunit α [IL-20RA], neurotrophin-3 and tumour necrosis factor receptor superfamily member 9), facial pain (CXCL1), back pain (TNF), shoulder pain (IL-17C and matrix metalloproteinase-10), stomach abdominal pain (IL-20RA), hip pain (C-C motif chemokine 11/eotaxin-1 and tumour necrosis factor ligand superfamily member 12) and knee pain (4EBP1). Importantly, in the opposite direction, MCP and SSCP did not exhibit a significant causal impact on circulating inflammatory proteins. Our study identified potential causal influences of various circulating inflammatory proteins on MCP and SSCP and provided promising treatments for the clinical management of MCP and SSCP.

The causal relationship between immune cells mediating FIT3L, CCL4, OSM, and skin-derived deteriorated tumors.

Observational studies have identified a dual effect of circulating inflammatory proteins and immune cells on cancer progression. However, the specific mechanisms of action have not been clarified in the exacerbation of cutaneous-origin tumors. Therefore, this study aims to investigate whether the causal relationship between circulating inflammatory factors and basal cell carcinoma (BCC), cutaneous malignant melanoma (SKCM), and cutaneous squamous cell carcinoma (cSCC) is regulated by immune cells. This study employed the Two-Sample Mendelian Randomization (TSMR) approach to investigate the causal relationships between 91 circulating inflammatory factors and three prevalent types of skin cancer from a genetic perspective. Bayesian Weighted Mendelian Randomization (BWMR) was also used to validate correlation and reverse MR to assess inverse relationships. Subsequent sensitivity analyses were conducted to limit the impact of heterogeneity and pleiotropy. Finally, the two-step Mendelian Randomization (two-step MR) method was utilized to ascertain the mediating effects of specific immune cell traits in the causal pathways linking circulating inflammatory factors with BCC, SKCM, and cSCC. The Inverse Variance Weighted (IVW) method and the Bayesian Weighted Algorithm collectively identified nine inflammatory factors causally associated with BCC, SKCM, and cSCC. The results from Cochran's Q test, mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO), and MR-Egger intercept were not statistically significant (p<0.05). Additionally, the proportions mediated by CD4+ CD8dim T cell %leukocyte, CD4-CD8-Natural Killer T %T cell, and CD20 on IgD-CD38-B cell for FIt3L, CCL4, and OSM were 9.26%, 8.96%, and 10.16%, respectively. Immune cell levels potentially play a role in the modulation process between circulating inflammatory proteins and cutaneous-origin exacerbated tumors. This finding offers a new perspective for the in-depth exploration of cutaneous malignancies.