scholarly journals Reverse causal effect of atrial fibrillation on 17 site-specific cancer risk: A Mendelian randomization study

Author(s):  
Sehoon Park ◽  
Soojin Lee ◽  
Yaerim Kim ◽  
Semin Cho ◽  
Kwangsoo Kim ◽  
...  

AbstractBackgroundBidirectional association between atrial fibrillation (AF) and cancer was reported by observational investigations. Additional study is warranted to investigate the causal effects of AF on risk of cancer.MethodsThis study was a summary-level Mendelian randomization (MR) analysis. Genetic instrument for AF was developed from a genome-wide association study (GWAS) meta-analysis for AF including 537,409 European ancestry individuals including 55,144 AF cases. The outcome data for risk of 17 site-specific cancer from a previous GWAS meta-analysis of the UK Biobank (48,961/359,825 case/controls) and Genetic Epidemiology Research on Adult Health and Aging (16,001/50,525 case/controls) cohorts including European ancestry individuals was investigated. Inverse variance weighted method was the main MR method, supported by pleiotropy-robust sensitivity analysis including MR-Egger regression and penalized weighted median method.ResultsThe causal estimates indicated that AF was causally linked to higher risk of cancers of lung, breast, cervix, endometrium, and melanoma. MR-Egger test for directional pleiotropy indicated absence of a pleiotropy in the identified causal estimates and MR-Egger regression and median-based methods provided similarly significant findings. On the other hand, the genetic predisposition of AF was significantly associated with lower risk of esophagus/gastric cancer, but possibility of a directional pleiotropy remained in the association.ConclusionsAF is a causal factor for certain types of cancer. Appropriate cancer screening should be suggested in clinical guidelines for AF patients. Future trial is necessary to confirm whether appropriate management of AF may reduce the risk of cancer which is a major cause of deaths in AF patients.

2022 ◽  
Vol 12 ◽  
Author(s):  
Yalan Li ◽  
Jun Lu ◽  
Jie Wang ◽  
Peizhi Deng ◽  
Changjiang Meng ◽  
...  

Background: Observational studies have revealed the association between some inflammatory cytokines and the occurrence of ischemic stroke, but the causal relationships remain unclear.Methods: We conducted a two-sample Mendelian randomization (MR) analysis to assess the causal effects of thirty inflammatory cytokines and the risk of ischemic stroke. For exposure data, we collected genetic variants associated with inflammatory cytokines as instrumental variables (IVs) from a genome-wide association study (GWAS) meta-analysis from Finland (sample size up to 8,293). For the outcome data, we collected summary data of ischemic stroke from a large-scale GWAS meta-analysis involved 17 studies (34,217 cases and 406,111 controls). We further performed a series of sensitivity analyses as validation of primary MR results.Results: According to the primary MR estimations and further sensitivity analyses, we established one robust association after Bonferroni correction: the odds ratio (95% CI) per unit change in genetically increased IL-4 was 0.84 (0.89–0.95) for ischemic stroke. The chemokine MCP3 showed a nominally significant association with ischemic stroke risk (OR: 0.93, 95% CI: 0.88–0.99, unadjusted p < 0.05). There was no evidence of a causal effect of other inflammatory cytokines and the risk of ischemic stroke.Conclusions: Our study suggested that genetically increased IL-4 levels showed a protective effect on the risk of ischemic stroke, which provides important new insights into the potential therapeutic target for preventing ischemic stroke.


Nutrients ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 233
Author(s):  
Maria K. Sobczyk ◽  
Tom R. Gaunt

Background & Aims: Previous results from observational, interventional studies and in vitro experiments suggest that certain micronutrients possess anti-viral and immunomodulatory activities. In particular, it has been hypothesized that zinc, selenium, copper and vitamin K1 have strong potential for prophylaxis and treatment of COVID-19. We aimed to test whether genetically predicted Zn, Se, Cu or vitamin K1 levels have a causal effect on COVID-19 related outcomes, including risk of infection, hospitalization and critical illness. Methods: We employed a two-sample Mendelian Randomization (MR) analysis. Our genetic variants derived from European-ancestry GWAS reflected circulating levels of Zn, Cu, Se in red blood cells as well as Se and vitamin K1 in serum/plasma. For the COVID-19 outcome GWAS, we used infection, hospitalization or critical illness. Our inverse-variance weighted (IVW) MR analysis was complemented by sensitivity analyses including a more liberal selection of variants at a genome-wide sub-significant threshold, MR-Egger and weighted median/mode tests. Results: Circulating micronutrient levels show limited evidence of association with COVID-19 infection, with the odds ratio [OR] ranging from 0.97 (95% CI: 0.87–1.08, p-value = 0.55) for zinc to 1.07 (95% CI: 1.00–1.14, p-value = 0.06)—i.e., no beneficial effect for copper was observed per 1 SD increase in exposure. Similarly minimal evidence was obtained for the hospitalization and critical illness outcomes with OR from 0.98 (95% CI: 0.87–1.09, p-value = 0.66) for vitamin K1 to 1.07 (95% CI: 0.88–1.29, p-value = 0.49) for copper, and from 0.93 (95% CI: 0.72–1.19, p-value = 0.55) for vitamin K1 to 1.21 (95% CI: 0.79–1.86, p-value = 0.39) for zinc, respectively. Conclusions: This study does not provide evidence that supplementation with zinc, selenium, copper or vitamin K1 can prevent SARS-CoV-2 infection, critical illness or hospitalization for COVID-19.


2020 ◽  
Author(s):  
Songzan Chen ◽  
Fangkun Yan ◽  
Tian Xu ◽  
Yao Wang ◽  
Kaijie Zhang ◽  
...  

Abstract Background Although several observational studies have shown an association between birth weight (BW) and atrial fibrillation (AF), controversy remains. In this study, we aimed to explore the role of elevated BW on the etiology of AF. Methods A two-sample Mendelian randomization (MR) study was designed to infer the causality. The genetic data on the associations of single nucleotide polymorphisms (SNPs) with BW and AF were separately obtained from two large-scale genome-wide association study with up to 321,223 and 1,030,836 individuals respectively. SNPs were identified at a genome-wide significant level (p-value < 5 × 10− 8). The inverse variance-weighted (IVW) with fixed effects method was performed to obtain causal estimates as our primary analysis. MR-Egger regression was conducted to assess the pleiotropy and sensitivity analyses with various statistical methods were applied to evaluate the robustness of the results. Results In total, 122 SNPs were identified as the genetic instrumental variables. MR analysis revealed a causal effect of elevated BW on AF (OR = 1.21, 95% CI = 1.13–1.29, p-value = 2.39 × 10− 8). The MR-Egger regression suggested no evidence of directional pleiotropy (intercept = 0.00, p-value = 0.62). All the results in sensitivity analyses were consistent with the primary result, which confirmed the causal association between BW and AF. Conclusions The findings from the two-sample MR study indicate a causal effect of elevated BW on AF. This suggests a convenient and effective method to ease the burden of AF by reducing the number of newborns with elevated BW.


Author(s):  
Bin He ◽  
Qiong Lyu ◽  
Lifeng Yin ◽  
Muzi Zhang ◽  
Zhengxue Quan ◽  
...  

AbstractObservational studies suggest a link between depression and osteoporosis, but these may be subject to confounding and reverse causality. In this two-sample Mendelian randomization analysis, we included the large meta-analysis of genome-wide association studies for depression among 807,553 individuals (246,363 cases and 561,190 controls) of European descent, the large meta-analysis to identify genetic variants associated with femoral neck bone mineral density (FN-BMD), forearm BMD (FA-BMD) and lumbar spine BMD (LS-BMD) among 53,236 individuals of European ancestry, and the GWAS summary data of heel BMD (HE-BMD) and fracture among 426,824 individuals of European ancestry. The results revealed that genetic predisposition towards depression showed no causal effect on FA-BMD (beta-estimate: 0.091, 95% confidence interval [CI] − 0.088 to 0.269, SE:0.091, P value = 0.320), FN-BMD (beta-estimate: 0.066, 95% CI − 0.016 to 0.148, SE:0.042, P value = 0.113), LS-BMD (beta-estimate: 0.074, 95% CI − 0.029 to 0.177, SE:0.052, P value = 0.159), HE-BMD (beta-estimate: 0.009, 95% CI − 0.043 to 0.061, SE:0.027, P value = 0.727), or fracture (beta-estimate: 0.008, 95% CI − 0.071 to 0.087, SE:0.041, P value = 0.844). These results were also confirmed by multiple sensitivity analyses. Contrary to the findings of observational studies, our results do not reveal a causal role of depression in osteoporosis or fracture.


PLoS Medicine ◽  
2021 ◽  
Vol 18 (6) ◽  
pp. e1003605
Author(s):  
Guillaume Butler-Laporte ◽  
Tomoko Nakanishi ◽  
Vincent Mooser ◽  
David R. Morrison ◽  
Tala Abdullah ◽  
...  

Background Increased vitamin D levels, as reflected by 25-hydroxy vitamin D (25OHD) measurements, have been proposed to protect against COVID-19 based on in vitro, observational, and ecological studies. However, vitamin D levels are associated with many confounding variables, and thus associations described to date may not be causal. Vitamin D Mendelian randomization (MR) studies have provided results that are concordant with large-scale vitamin D randomized trials. Here, we used 2-sample MR to assess evidence supporting a causal effect of circulating 25OHD levels on COVID-19 susceptibility and severity. Methods and findings Genetic variants strongly associated with 25OHD levels in a genome-wide association study (GWAS) of 443,734 participants of European ancestry (including 401,460 from the UK Biobank) were used as instrumental variables. GWASs of COVID-19 susceptibility, hospitalization, and severe disease from the COVID-19 Host Genetics Initiative were used as outcome GWASs. These included up to 14,134 individuals with COVID-19, and up to 1,284,876 without COVID-19, from up to 11 countries. SARS-CoV-2 positivity was determined by laboratory testing or medical chart review. Population controls without COVID-19 were also included in the control groups for all outcomes, including hospitalization and severe disease. Analyses were restricted to individuals of European descent when possible. Using inverse-weighted MR, genetically increased 25OHD levels by 1 standard deviation on the logarithmic scale had no significant association with COVID-19 susceptibility (odds ratio [OR] = 0.95; 95% CI 0.84, 1.08; p = 0.44), hospitalization (OR = 1.09; 95% CI: 0.89, 1.33; p = 0.41), and severe disease (OR = 0.97; 95% CI: 0.77, 1.22; p = 0.77). We used an additional 6 meta-analytic methods, as well as conducting sensitivity analyses after removal of variants at risk of horizontal pleiotropy, and obtained similar results. These results may be limited by weak instrument bias in some analyses. Further, our results do not apply to individuals with vitamin D deficiency. Conclusions In this 2-sample MR study, we did not observe evidence to support an association between 25OHD levels and COVID-19 susceptibility, severity, or hospitalization. Hence, vitamin D supplementation as a means of protecting against worsened COVID-19 outcomes is not supported by genetic evidence. Other therapeutic or preventative avenues should be given higher priority for COVID-19 randomized controlled trials.


2022 ◽  
Vol 12 ◽  
Author(s):  
Yong-Bo Wang ◽  
Si-Yu Yan ◽  
Xu-Hui Li ◽  
Qiao Huang ◽  
Li-Sha Luo ◽  
...  

Background: Previous observational studies have reported a bidirectional association between periodontitis and type 2 diabetes, but the causality of these relationships remains unestablished. We clarified the bidirectional causal association through two-sample Mendelian randomization (MR).Methods: We obtained summary-level data for periodontitis and type 2 diabetes from several published large-scale genome-wide association studies (GWAS) of individuals of European ancestry. For the casual effect of periodontitis on type 2 diabetes, we used five independent single-nucleotide polymorphisms (SNPs) specific to periodontitis from three GWAS. The summary statistics for the associations of exposure-related SNPs with type 2 diabetes were drawn from the GWAS in the Diabetes Genetics Replication and Meta-analysis (DIAGRAM) consortium and the FinnGen consortium R5 release, respectively. For the reversed causal inference, 132 and 49 SNPs associated with type 2 diabetes from the DIAGRAM consortium and the FinnGen consortium R5 release were included, and the summary-level statistics were obtained from the Gene-Lifestyle Interactions in Dental Endpoints consortium. Multiple approaches of MR were carried out.Results: Periodontitis was not causally related with the risk of type 2 diabetes (all p &gt; 0.05). No causal effect of type 2 diabetes on periodontitis was found (all p &gt; 0.05). Estimates were consistent across multiple MR analyses.Conclusion: This study based on genetic data does not support a bidirectional causal association between periodontitis and type 2 diabetes.


2020 ◽  
Vol 8 (1) ◽  
pp. e920
Author(s):  
Adil Harroud ◽  
J. Brent Richards ◽  
Sergio E. Baranzini

ObjectiveTo examine whether lifelong genetically increased serum urate levels, a potent antioxidant, contribute to MS susceptibility using Mendelian randomization (MR).MethodsThis 2-sample MR study included 25 independent genetic variants strongly associated with serum urate levels in a genome-wide association study meta-analysis of 140,949 individuals. Effects on the risk of MS were assessed with summary statistics from 3 large-scale MS genetic data sets totaling 61,667 MS cases and 86,806 controls from the International MS Genetic Consortium. Multiple sensitivity analyses were performed to evaluate the assumptions of MR and remove potentially pleiotropic variants.ResultsUsing inverse-variance weighted MR, we found no evidence for a causal effect of serum urate level on the risk of MS in any of the cohorts (MS1: OR 0.99 per each mg/dL unit increase in urate, 95% CI 0.89–1.08, p = 0.76; MS2: OR = 0.99, 95% CI 0.89–1.11, p = 0.90; MS3: OR = 1.00, 95% CI 0.98–1.2, p = 0.91). Pleiotropy robust MR methods yielded consistent estimates.ConclusionThis MR study does not support a clinically relevant causal effect of serum urate levels on the risk of MS.


2021 ◽  
Author(s):  
Huachen Wang ◽  
Zheng Guo ◽  
Yulu Zheng ◽  
Bing Chen

Abstract Background: Current research observing inconsistent associations of Corona Virus Disease 2019 (COVID-19) with heart failure (HF) are prone to bias based on reverse causality and residual confounding factors. Our aim was to apply a two-sample Mendelian randomization method to investigate whether COVID-19 has a causal effect on HF. Methods: Twenty-nine single nucleotide polymorphisms (SNPs) were proposed as candidate instrumental variables (IVs). A total of 3,523 patients with COVID-19 and 36,634 control participants were included in the genome-wide meta-analysis. We analyzed the largest genome-wide association studies (GWAS) meta-analysis of heart failure in individuals of European ancestry consisting of 47,309 patients with HF and 930,014 controls. The inverse variance weighted (IVW), the Mendelian randomization-Egger (MR-Egger) regression, the simple mode (SM), weighted median, and weighted mode were utilized for the MR analysis to test the stability and a causal effect. Results: The IVW, MR-Egger regression, SM, weighted median and weighted mode demonstrated there was no association between the genetically predicted COVID-19 infection and HF risk (OR, 1.004; 95%CI, 0.994-1.014; P=0.467; OR, 1.008; 95%CI, 0.996-1.019; P=0.218; OR, 0.968; 95%CI, 0.924-1.015; P=0.186; OR, 1.001; 95%CI, 0.988-1.014; P=0.881; OR, 1.001; 95%CI, 0.989-1.014; P=0.836; respectively). Conclusion: This two-sample Mendelian randomization analysis provided no evidence to sustain the causality of COVID-19 on HF.


2021 ◽  
Author(s):  
Tianyi Wang ◽  
Jun Cheng ◽  
Yanggan Wang

Background Atrial fibrillation is the most common arrhythmia disease.Animal and observational studies have found a link between iron status and atrial fibrillation. However, the causal relationship between iron status and the risk of atrial fibrillation may be biased by confounding and reverse causality.The purpose of this investigation was to use Mendelian randomization (MR) analysis, which has been widely appied to estimate the causal effect,to reveal whether systemic iron status was causally related to atrial fibrillation. Methods Single nucleotide polymorphisms (SNPs) strongly associated (P< 5.10-8) with four biomarkers of systemic iron status were obtained from a genome-wide association study involving 48,972 subjects conducted by the Genetics of Iron Status consortium. Summary-level data for the genetic associations with atrial fibrillation were acquired from AFGen (Atrial Fibrillation Genetics) consortium study( including 65,446 atrial fibrillation cases and 522,744 controls) .We used a two-sample MR analysis to obtain a causal estimate, and further verified credibility through sensitivity analysis. Results Genetically instrumented serum iron [OR:1.09;95%; confidence interval (CI)1.02-1.16; p=0.01], ferritin [OR:1.16;95%CI:1.02-1.33; p=0.02], and transferrin saturation [OR:1.05;95%CI:1.01-1.11; p=0.01] had positive effects on atrial fibrillation. Genetically instrumented transferrin levels [OR:0.90;95%CI:0.86-0.97; p=0.006] was an inverse correlation with atrial fibrillation. Conclusion In conclusion,our results strongly elucidated a causal link between genetically determined higher iron status and increased the risk of atrial fibrillation.This provided new ideas for clinical prevention and treatment of atrial fibrillation.


Author(s):  
Shuai Yuan ◽  
Maria Bruzelius ◽  
Susanna C. Larsson

AbstractWhether renal function is causally associated with venous thromboembolism (VTE) is not yet fully elucidated. We conducted a two-sample Mendelian randomization (MR) study to determine the causal effect of renal function, measured as estimated glomerular filtration rate (eGFR), on VTE. Single-nucleotide polymorphisms associated with eGFR were selected as instrumental variables at the genome-wide significance level (p < 5 × 10−8) from a meta-analysis of 122 genome-wide association studies including up to 1,046,070 individuals. Summary-level data for VTE were obtained from the FinnGen consortium (6913 VTE cases and 169,986 non-cases) and UK Biobank study (4620 VTE cases and 356,574 non-cases). MR estimates were calculated using the random-effects inverse-variance weighted method and combined using fixed-effects meta-analysis. Genetically predicted decreased eGFR was significantly associated with an increased risk of VTE in both FinnGen and UK Biobank. For one-unit decrease in log-transformed eGFR, the odds ratios of VTE were 2.93 (95% confidence interval (CI) 1.25, 6.84) and 4.46 (95% CI 1.59, 12.5) when using data from FinnGen and UK Biobank, respectively. The combined odds ratio was 3.47 (95% CI 1.80, 6.68). Results were consistent in all sensitivity analyses and no horizontal pleiotropy was detected. This MR-study supported a casual role of impaired renal function in VTE.


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