Publications
261 results found
Zhang Z, Wang M, Gill D, et al., 2023, Genetically Predicted Sleep Traits and Functional Outcome After Ischemic Stroke: A Mendelian Randomization Study., Neurology, Vol: 100, Pages: e1159-e1165
BACKGROUND AND OBJECTIVES: Sleep traits can have implications for ischemic stroke recovery in observational studies. The purpose of our present study was to explore the relationship between genetically predicted sleep traits and poststroke functional outcomes with Mendelian randomization (MR) method. METHODS: Instrumental variables for insomnia and sleep duration were adopted from genome-wide association studies data of European ancestry individuals. Summary data for functional outcome after ischemic stroke were retrieved from the Genetics of Ischemic Stroke Functional Outcome network. Inverse-variance weighted approach was adopted as the main analyses. Alternative MR approaches were used in sensitivity analyses. I2 and Q value statistics were used to appraise the heterogeneity among genetic variants. RESULTS: In univariable analysis, genetic liability to insomnia was significantly associated with worse functional outcome (modified Rankin Scale ≥3) after ischemic stroke (odds ratio [OR] = 1.30; 95% CI: 1.10-1.54, p = 0.002). Genetic liability to short sleep, long sleep, and continuous sleep duration were not associated with poststroke functional outcome (all p > 0.05). Sensitivity analyses without adjustment for stroke severity also supported that insomnia was causally associated with poor functional outcome (OR = 1.25; 95% CI: 1.08-1.44, p = 0.003). In the multivariable MR analysis adjusting for potentially confounding traits including body mass index, depression, type 2 diabetes, smoking, and alcohol consumption, the overall patterns between genetic liability to insomnia and poststroke outcome remained (all p < 0.05). DISCUSSION: This MR study supports potential adverse effects of liability to insomnia on functional outcome after ischemic stroke. Interventions that address insomnia may offer a therapeutic target to improve recovery after ischemic stroke and warrant exploration in a clinical context.
Chalitsios CV, Georgiou A, Bouras E, et al., 2023, Investigating modifiable pathways in psoriasis: A Mendelian randomization study., J Am Acad Dermatol, Vol: 88, Pages: 593-601
BACKGROUND: Potentially modifiable risk factors have previously been investigated only in conventional observational studies. OBJECTIVE: To assess whether genetically predicted exposures to modifiable factors are associated with the risk of psoriasis. METHODS: Two-sample Mendelian randomization (MR) analysis. RESULTS: An increased risk of psoriasis was noted for genetically predicted lifetime smoking index (odds ratio [OR]MR-IVW = 2.11; 95% confidence interval [CI], 1.28-3.51), childhood (OR MR-IVW = 1.40; 95% CI, 1.14-1.71) and adult body mass index (OR MR-IVW = 1.63; 95% CI, 1.32-2), waist (OR IVW = 1.86; 95% CI, 1.31-2.64), and hip circumference (OR MR-IVW = 1.55; 95% CI, 1.15-2.07). Protective association was also reported between genetically predicted longer sleep duration (OR MR-IVW = 0.56; 95% CI 0.37-0.84) and increased years of education (OR MR-IVW = 0.78; 95% CI, 0.62-0.98). This effect of education persisted in multivariable MR after adjusting for genetic predictors of smoking and adult body mass index (ORMVMR-IVW = 0.72; 95% CI, 0.56-0.92). LIMITATIONS: It was not possible to stratify for psoriasis severity. CONCLUSION: Smoking cessation and prevention of obesity are important strategies for decreasing the incidence of psoriasis. Similarly, targeting education inequality is expected to lead further to reductions in cases of psoriasis.
Yuan S, Wang L, Zhang H, et al., 2023, Mendelian randomization and clinical trial evidence supports TYK2 inhibition as a therapeutic target for autoimmune diseases., EBioMedicine, Vol: 89
BACKGROUND: To explore the associations of genetically proxied TYK2 inhibition with a wide range of disease outcomes and biomarkers to identify therapeutic repurposing opportunities, adverse effects, and biomarkers of efficacy. METHODS: The loss-of-function missense variant rs34536443 in TYK2 gene was used as a genetic instrument to proxy the effect of TYK2 inhibition. A phenome-wide Mendelian randomization (MR) study was conducted to explore the associations of genetically-proxied TYK2 inhibition with 1473 disease outcomes in UK Biobank (N = 339,197). Identified associations were examined for replication in FinnGen (N = 260,405). We further performed tissue-specific gene expression MR, colocalization analyses, and MR with 247 blood biomarkers. A systematic review of randomized controlled trials (RCTs) on TYK2 inhibitor was performed to complement the genetic evidence. FINDINGS: PheWAS-MR found that genetically-proxied TYK2 inhibition was associated with lower risk of a wide range of autoimmune diseases. The associations with hypothyroidism and psoriasis were confirmed in MR analysis of tissue-specific TYK2 gene expression and the associations with systemic lupus erythematosus, psoriasis, and rheumatoid arthritis were observed in colocalization analysis. There were nominal associations of genetically-proxied TYK2 inhibition with increased risk of prostate and breast cancer but not in tissue-specific expression MR or colocalization analyses. Thirty-seven blood biomarkers were associated with the TYK2 loss-of-function mutation. Evidence from RCTs confirmed the effectiveness of TYK2 inhibitors on plaque psoriasis and reported several adverse effects. INTERPRETATION: This study supports TYK2 inhibitor as a potential treatment for psoriasis and several other autoimmune diseases. Increased pharmacovigilance is warranted in relation to the potential adverse effects. FUNDING: None.
Huang J, Gill D, Zuber V, et al., 2023, Circulatory proteins relate cardiovascular disease to cognitive performance: a Mendelian randomisation study, Frontiers in Genetics, Vol: 14, Pages: 1-11, ISSN: 1664-8021
Background and objectives: Mechanistic research suggests synergistic effects of cardiovascular disease (CVD) and dementia pathologies on cognitive decline. Interventions targeting proteins relevant to shared mechanisms underlying CVD and dementia could also be used for the prevention of cognitive impairment.Methods: We applied Mendelian randomisation (MR) and colocalization analysis to investigate the causal relationships of 90 CVD-related proteins measured by the Olink CVD I panel with cognitive traits. Genetic instruments for circulatory protein concentrations were obtained using a meta-analysis of genome-wide association studies (GWAS) from the SCALLOP consortium (N = 17,747) based on three sets of criteria: 1) protein quantitative trait loci (pQTL); 2) cis-pQTL (pQTL within ±500 kb from the coding gene); and 3) brain-specific cis-expression QTL (cis-eQTL) which accounts for coding gene expression based on GTEx8. Genetic associations of cognitive performance were obtained from GWAS for either: 1) general cognitive function constructed using Principal Component Analysis (N = 300,486); or, 2) g Factor constructed using genomic structural equation modelling (N = 11,263–331,679). Findings for candidate causal proteins were replicated using a separate protein GWAS in Icelanders (N = 35,559).Results: A higher concentration of genetically predicted circulatory myeloperoxidase (MPO) was nominally associated with better cognitive performance (p < 0.05) using different selection criteria for genetic instruments. Particularly, brain-specific cis-eQTL predicted MPO, which accounts for protein-coding gene expression in brain tissues, was associated with general cognitive function (βWald = 0.22, PWald = 2.4 × 10−4). The posterior probability for colocalization (PP.H4) of MPO pQTL with the g Factor was 0.577. Findings for MPO were replicated using the Icelandic GWAS. Although we did not find evidence for colocalization, we found that higher gene
Chen J, Yuan S, Fu T, et al., 2023, Gastrointestinal Consequences of Type 2 Diabetes Mellitus and Impaired Glycemic Homeostasis: A Mendelian Randomization Study., Diabetes Care
OBJECTIVE: We conducted a Mendelian randomization (MR) study to examine the associations of type 2 diabetes and glycemic traits with gastrointestinal diseases (GDs). RESEARCH DESIGN AND METHODS: Uncorrelated genetic variants associated with type 2 diabetes (n = 231), fasting insulin (n = 38), fasting glucose (n = 71), and hemoglobin A1c (n = 75) at the genome-wide significance were selected as instrument variables. Genetic associations with 23 common GDs were obtained from the FinnGen and UK Biobank studies and other large consortia. RESULTS: Genetic liability to type 2 diabetes was associated with the risk of 12 GDs. Per 1-unit increase in the log-transformed odds ratio (OR) of type 2 diabetes, the OR was 1.06 (95% CI, 1.03-1.09) for gastroesophageal reflux disease, 1.12 (95% CI, 1.07-1.17) for gastric ulcer, 1.11 (95% CI, 1.03-1.20) for acute gastritis, 1.07 (95% CI, 1.01-1.13) for chronic gastritis, 1.08 (95% CI, 1.03-1.12) for irritable bowel syndrome, 1.04 (95% CI, 1.01-1.07) for diverticular disease, 1.08 (95% CI, 1.02-1.14) for acute pancreatitis, 1.09 (95% CI, 1.05-1.12) for cholelithiasis, 1.09 (95% CI, 1.05-1.13) for cholelithiasis with cholecystitis, 1.29 (95% CI, 1.17-1.43) for nonalcoholic fatty liver disease, 1.12 (95% CI, 1.03-1.21) for liver cirrhosis, and 0.93 (95% CI, 0.89-0.97) for ulcerative colitis. Genetically predicted higher levels of fasting insulin and glucose were associated with six and one GDs, respectively. CONCLUSIONS: Associations were found between genetic liability to type 2 diabetes and an increased risk of a broad range of GDs, highlighting the importance of GD prevention in patients with type 2 diabetes.
Cao L, Liu D, Karhunen V, et al., 2023, Circulating macrophage colony-stimulating factor levels and stroke: A Mendelian randomization study., J Stroke Cerebrovasc Dis, Vol: 32
OBJECTIVES: Colony-stimulating factor 1 (CSF1), also known as macrophage colony-stimulating factor, has been shown to be associated with risk of ischemic stroke in conventional epidemiological study. We performed a Mendelian randomization analysis to evaluate the effects of genetically predicted circulating CSF1 levels on stroke and carotid intima-media thickness (cIMT). METHODS: Genetic variants robustly associated with CSF1 levels, located in the vicinity of the CSF1 gene (cis), were used as instruments for CSF1 levels. Genetic association estimates for ischemic stroke and its subtypes, intra-cerebral hemorrhage (ICH), and cIMT were obtained from MEGASTROKE (60,341 cases and 454,450 controls), ISGC (1,545 cases and 1,481 controls), and UK Biobank (22,179 individuals), respectively. RESULTS: Genetically predicted higher CSF1 levels was significantly associated with a higher risk of any ischemic stroke, large artery stroke (LAS) and cardioembolic stroke (CES), but not with small vessel stroke (SVS) and ICH. The odds ratios (ORs) per genetically predicted one standard deviation (SD) increase in circulating CSF1 levels were 1.11 (95% CI 1.04-1.17) for any ischemic stroke, 1.23 (95% CI 1.07-1.42) for LAS, 1.18 (95% CI 1.05-1.33) for CES, 1.07 (95% CI 0.94-1.21) for SVS, and 1.15 (95% CI 0.73-1.83) for ICH. Similarly, we also found that genetically predicted higher CSF1 levels were associated with higher cIMT, as a measure of subclinical atherosclerosis (cIMT, β 0.016, 95% CI, 0.004-0.029). CONCLUSIONS: This study provides evidence that genetically predicted higher CSF1 levels was associated with higher risk of any ischemic stroke, LAS, and CES. Whether targeting CSF1 or its receptors can reduce the risk of ischemic stroke needs further study.
Huang J, Su B, Karhunen V, et al., 2023, Inflammatory diseases, inflammatory biomarkers, and Alzheimer disease: an observational analysis and mendelian randomization, Neurology, Vol: 100, Pages: e568-e581, ISSN: 0028-3878
OBJECTIVES: Whether chronic autoimmune inflammatory diseases causally affect the risk of AD is controversial. We characterised the relationship between inflammatory diseases and the risk of AD and explore the role of circulating inflammatory biomarkers in the relationships between inflammatory diseases and AD. METHODS: We performed observational analyses for chronic autoimmune inflammatory diseases and risk of AD using data from 2,047,513 participants identified in the UK Clinical Practice Research Datalink (CPRD). Using data of a total of more than 1,100,000 individuals from 15 large scale genome-wide association study (GWAS) datasets, we performed two-sample Mendelian randomisation (MR) to investigate the relationships between chronic autoimmune inflammatory diseases, circulating inflammatory biomarker levels, and risk of AD. RESULTS: Cox regression models using CPRD data showed that overall incidence of AD was higher among patients with inflammatory bowel disease (IBD) (hazard ratio (HR)=1.17; 95%CI 1.15 to 1.19; P-value=2.1×10-4), other inflammatory polyarthropathies & systematic connective tissue disorders (OID) (HR=1.13; 95%CI 1.12 to 1.14; P-value=8.6×10-5), psoriasis (HR=1.13; 95%CI 1.10 to 1.16; P-value=2.6×10-4), rheumatoid arthritis (RA) (HR=1.08; 95%CI 1.06 to 1.11; P-value=4.0×10-4), and multiple sclerosis (MS) (HR=1.06; 95%CI 1.04 to 1.07; P-value=2.8×10-4) compared to the age (± 5 years) and sex-matched comparison groups free from all inflammatory diseases under investigation. Bidirectional MR analysis identified relationships between chronic autoimmune inflammatory diseases and circulating inflammatory biomarkers. Particularly, circulating monokine induced by gamma interferon (MIG) level was suggestively associated with a higher risk of AD (odds ratio from inverse variance weighted (ORIVW)=1.23; 95%CI 1.06 to 1.42; PIVW=0.007), and lower risk of Crohn's disease (ORIVW=0.73; 95%CI -0.62, 0.86; PIVW=1.3×10
Yuan S, Chen J, Ruan X, et al., 2023, Smoking, alcohol consumption, and 24 gastrointestinal diseases: Mendelian randomization analysis., Elife, Vol: 12
BACKGROUND: Whether the positive associations of smoking and alcohol consumption with gastrointestinal diseases are causal is uncertain. We conducted this Mendelian randomization (MR) to comprehensively examine associations of smoking and alcohol consumption with common gastrointestinal diseases. METHODS: Genetic variants associated with smoking initiation and alcohol consumption at the genome-wide significance level were selected as instrumental variables. Genetic associations with 24 gastrointestinal diseases were obtained from the UK Biobank, FinnGen study, and other large consortia. Univariable and multivariable MR analyses were conducted to estimate the overall and independent MR associations after mutual adjustment for genetic liability to smoking and alcohol consumption. RESULTS: Genetic predisposition to smoking initiation was associated with increased risk of 20 of 24 gastrointestinal diseases, including 7 upper gastrointestinal diseases (gastroesophageal reflux, esophageal cancer, gastric ulcer, duodenal ulcer, acute gastritis, chronic gastritis, and gastric cancer), 4 lower gastrointestinal diseases (irritable bowel syndrome, diverticular disease, Crohn's disease, and ulcerative colitis), 8 hepatobiliary and pancreatic diseases (non-alcoholic fatty liver disease, alcoholic liver disease, cirrhosis, liver cancer, cholecystitis, cholelithiasis, and acute and chronic pancreatitis), and acute appendicitis. Fifteen out of 20 associations persisted after adjusting for genetically predicted alcohol consumption. Genetically predicted higher alcohol consumption was associated with increased risk of duodenal ulcer, alcoholic liver disease, cirrhosis, and chronic pancreatitis; however, the association for duodenal ulcer did not remain statistically significant after adjustment for genetic predisposition to smoking initiation. CONCLUSIONS: This study provides MR evidence supporting causal associations of smoking with a broad range of gastrointestinal diseases, wherea
Burgess S, Mason AM, Grant AJ, et al., 2023, Using genetic association data to guide drug discovery and development: review of methods and applications, American Journal of Human Genetics, Vol: 110, Pages: 195-214, ISSN: 0002-9297
Evidence on the validity of drug targets from randomized trials is reliable but typically expensive and slow to obtain. In contrast, evidence from conventional observational epidemiological studies is less reliable because of the potential for bias from confounding and reverse causation. Mendelian randomization is a quasi-experimental approach analogous to a randomized trial that exploits naturally occurring randomization in the transmission of genetic variants. In Mendelian randomization, genetic variants that can be regarded as proxies for an intervention on the proposed drug target are leveraged as instrumental variables to investigate potential effects on biomarkers and disease outcomes in large-scale observational datasets. This approach can be implemented rapidly for a range of drug targets to provide evidence on their effects and thus inform on their priority for further investigation. In this review, we present statistical methods and their applications to showcase the diverse opportunities for applying Mendelian randomization in guiding clinical development efforts, thus enabling interventions to target the right mechanism in the right population group at the right time. These methods can inform investigators on the mechanisms underlying drug effects, their related biomarkers, implications for the timing of interventions, and the population subgroups that stand to gain the most benefit. Most methods can be implemented with publicly available data on summarized genetic associations with traits and diseases, meaning that the only major limitations to their usage are the availability of appropriately powered studies for the exposure and outcome and the existence of a suitable genetic proxy for the proposed intervention.
DePaolo J, Levin MG, Tcheandjieu C, et al., 2023, Relationship Between Ascending Thoracic Aortic Diameter and Blood Pressure: A Mendelian Randomization Study, ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY, Vol: 43, Pages: 359-366, ISSN: 1079-5642
Ryan D, Karhunen V, Su B, et al., 2023, Genetic evidence for protective effects of angiotensin converting enzyme against Alzheimer's disease but not other neurodegenerative diseases, Pharmacology Annual Meeting, Publisher: WILEY, Pages: 565-567, ISSN: 0007-1188
Bakker MK, van Straten T, Chong M, et al., 2023, Anti-Epileptic Drug Target Perturbation and Intracranial Aneurysm Risk: Mendelian Randomization and Colocalization Study, STROKE, Vol: 54, Pages: 208-216, ISSN: 0039-2499
Fang S, Yarmolinsky J, Gill D, et al., 2023, Association between genetically proxied PCSK9 inhibition and prostate cancer risk: A Mendelian randomisation study., PLoS Med, Vol: 20
BACKGROUND: Prostate cancer (PrCa) is the second most prevalent malignancy in men worldwide. Observational studies have linked the use of low-density lipoprotein cholesterol (LDL-c) lowering therapies with reduced risk of PrCa, which may potentially be attributable to confounding factors. In this study, we performed a drug target Mendelian randomisation (MR) analysis to evaluate the association of genetically proxied inhibition of LDL-c-lowering drug targets on risk of PrCa. METHODS AND FINDINGS: Single-nucleotide polymorphisms (SNPs) associated with LDL-c (P < 5 × 10-8) from the Global Lipids Genetics Consortium genome-wide association study (GWAS) (N = 1,320,016) and located in and around the HMGCR, NPC1L1, and PCSK9 genes were used to proxy the therapeutic inhibition of these targets. Summary-level data regarding the risk of total, advanced, and early-onset PrCa were obtained from the PRACTICAL consortium. Validation analyses were performed using genetic instruments from an LDL-c GWAS conducted on male UK Biobank participants of European ancestry (N = 201,678), as well as instruments selected based on liver-derived gene expression and circulation plasma levels of targets. We also investigated whether putative mediators may play a role in findings for traits previously implicated in PrCa risk (i.e., lipoprotein a (Lp(a)), body mass index (BMI), and testosterone). Applying two-sample MR using the inverse-variance weighted approach provided strong evidence supporting an effect of genetically proxied inhibition of PCSK9 (equivalent to a standard deviation (SD) reduction in LDL-c) on lower risk of total PrCa (odds ratio (OR) = 0.85, 95% confidence interval (CI) = 0.76 to 0.96, P = 9.15 × 10-3) and early-onset PrCa (OR = 0.70, 95% CI = 0.52 to 0.95, P = 0.023). Genetically proxied HMGCR inhibition provided a similar central effect estimate on PrCa risk, although with a wider 95% CI (OR = 0.83, 95% CI = 0.62 to 1.13, P = 0.244), whereas genetically proxie
Karhunen V, Gill D, Huang J, et al., 2023, The interplay between inflammatory cytokines and cardiometabolic disease: bi-directional mendelian randomisation study., BMJ Med, Vol: 2
OBJECTIVE: To leverage large scale genetic association data to investigate the interplay between circulating cytokines and cardiometabolic traits, and thus identifying potential therapeutic targets. DESIGN: Bi-directional Mendelian randomisation study. SETTING: Genome-wide association studies from three Finnish cohorts (Northern Finland Birth Cohort 1966, Young Finns Study, or FINRISK study), and genetic association summary statistics pooled from observational studies for expression quantitative trait loci and cardiometabolic traits. PARTICIPANTS: Data for 47 circulating cytokines in 13 365 individuals from genome-wide association studies, summary statistic data for up to 21 735 individuals on circulating cytokines, summary statistic gene expression data across 49 tissues in 838 individuals, and summary statistic data for up to 1 320 016 individuals on cardiometabolic traits. INTERVENTIONS: Relations between circulating cytokines and cardiovascular, anthropometric, lipid, or glycaemic traits (coronary artery disease, stroke, type 2 diabetes mellitus, body mass index, waist circumference, waist to hip ratio, systolic blood pressure, glycated haemoglobin, high density lipoprotein cholesterol, low density lipoprotein cholesterol, total cholesterol, triglycerides, C reactive protein, glucose, fasting insulin, and lifetime smoking). MAIN OUTCOME METHODS: Genetic instrumental variables that are biologically plausible for the circulating cytokines were generated. The effects of cardiometabolic risk factors on concentrations of circulating cytokines, circulating cytokines on other circulating cytokines, and circulating cytokines on cardiometabolic outcomes were investigated. RESULTS: Genetic evidence (mendelian randomisation P<0.0011) suggests that higher body mass index, waist circumference, smoking, higher concentrations of lipids, and systolic blood pressure increase circulating concentrations of several inflammatory cytokines and C reactive protein. Evi
Larsson SC, Woolf B, Gill D, 2023, Appraisal of the causal effect of plasma caffeine on adiposity, type 2 diabetes, and cardiovascular disease: two sample mendelian randomisation study., BMJ Med, Vol: 2, Pages: 1-8
OBJECTIVE: To investigate the potential causal effects of long term plasma caffeine concentrations on adiposity, type 2 diabetes, and major cardiovascular diseases. DESIGN: Two sample mendelian randomisation study. SETTING: Genome-wide association study summary data for associations of two single nucleotide polymorphisms associated with plasma caffeine at the genome-wide significance threshold (rs2472297 near the CYP1A2 gene and rs4410790 near the AHR gene) and their association with the outcomes. PARTICIPANTS: Primarily individuals of European ancestry participating in cohorts contributing to genome-wide association study consortia. MAIN OUTCOME MEASURES: Outcomes studied were body mass index, whole body fat mass, whole body fat-free mass, type 2 diabetes, ischaemic heart disease, atrial fibrillation, heart failure, and stroke. RESULTS: Higher genetically predicted plasma caffeine concentrations were associated with lower body mass index (beta -0.08 standard deviation (SD) (95% confidence interval -0.10 to -0.06), where 1 SD equals about 4.8 kg/m2 in body mass index, for every standard deviation increase in plasma caffeine) and whole body fat mass (beta -0.06 SD (-0.08 to -0.04), 1 SD equals about 9.5 kg; P<0.001) but not fat-free mass (beta -0.01 SD (-0.02 to -0.00), 1 SD equals about 11.5 kg; P=0.17). Higher genetically predicted plasma caffeine concentrations were associated with a lower risk of type 2 diabetes in two consortia (FinnGen and DIAMANTE), with a combined odds ratio of 0.81 ((95% confidence interval 0.74 to 0.89); P<0.001). Approximately half (43%; 95% confidence interval 30% to 61%) of the effect of caffeine on type 2 diabetes was estimated to be mediated through body mass index reduction. No strong associations were reported between genetically predicted plasma caffeine concentrations and a risk of any of the studied cardiovascular diseases. CONCLUSIONS: Higher plasma caffeine concentrations might reduce adiposity and risk of type 2 diabetes.
Zagkos L, Dib M-J, Pinto R, et al., 2022, Associations of genetically predicted fatty acid levels across the phenome: a mendelian randomisation study, PLoS Medicine, Vol: 19, ISSN: 1549-1277
BACKGROUND: Fatty acids are important dietary factors that have been extensively studied for their implication in health and disease. Evidence from epidemiological studies and randomised controlled trials on their role in cardiovascular, inflammatory, and other diseases remains inconsistent. The objective of this study was to assess whether genetically predicted fatty acid concentrations affect the risk of disease across a wide variety of clinical health outcomes. METHODS AND FINDINGS: The UK Biobank (UKB) is a large study involving over 500,000 participants aged 40 to 69 years at recruitment from 2006 to 2010. We used summary-level data for 117,143 UKB samples (base dataset), to extract genetic associations of fatty acids, and individual-level data for 322,232 UKB participants (target dataset) to conduct our discovery analysis. We studied potentially causal relationships of circulating fatty acids with 845 clinical diagnoses, using mendelian randomisation (MR) approach, within a phenome-wide association study (PheWAS) framework. Regression models in PheWAS were adjusted for sex, age, and the first 10 genetic principal components. External summary statistics were used for replication. When several fatty acids were associated with a health outcome, multivariable MR and MR-Bayesian method averaging (MR-BMA) was applied to disentangle their causal role. Genetic predisposition to higher docosahexaenoic acid (DHA) was associated with cholelithiasis and cholecystitis (odds ratio per mmol/L: 0.76, 95% confidence interval: 0.66 to 0.87). This was supported in replication analysis (FinnGen study) and by the genetically predicted omega-3 fatty acids analyses. Genetically predicted linoleic acid (LA), omega-6, polyunsaturated fatty acids (PUFAs), and total fatty acids (total FAs) showed positive associations with cardiovascular outcomes with support from replication analysis. Finally, higher genetically predicted levels of DHA (0.83, 0.73 to 0.95) and omega-3 (0.83, 0.75 to 0.
Jiang T, Gill D, Butterworth AS, et al., 2022, An empirical investigation into the impact of winner's curse on estimates from Mendelian randomization, INTERNATIONAL JOURNAL OF EPIDEMIOLOGY, ISSN: 0300-5771
Yuan S, Chen J, Vujkovic M, et al., 2022, The effects of metabolic traits, lifestyle factors and pharmacological interventions on liver fat: a mendelian randomisation study, BMJ Medicine, Vol: 1, ISSN: 2754-0413
Objective: To investigate the effects of metabolic traits, lifestyle factors, and drug interventions on liver fat using the mendelian randomisation paradigm.Design: Mendelian randomisation study.Setting: Publicly available summary level data from genome-wide association studies.Participants: Genome-wide association studies of 32 974 to 1 407 282 individuals who were predominantly of European descent.Exposures: Genetic variants predicting nine metabolic traits, six lifestyle factors, four lipid lowering drug targets, three antihypertensive drug targets, and genetic association estimates formagnetic resonance imaging measured liver fat.Main outcome measures: Mendelian randomisation analysis was used to investigate the effects of these exposures on liver fat, incorporating sensitivity analyses that relaxed the requisite modelling assumptions.Results: Genetically predicted liability to obesity, type 2 diabetes, elevated blood pressure, elevated triglyceride levels, cigarette smoking, and sedentary time watching television were associated with higher levels of liver fat. Genetically predicted lipid lowering drug effects were not associated with liver fat; however, β blocker and calcium channel blocker antihypertensive drug effects were associated with lower levels of liver fat.Conclusion: These analyses provide evidence of a causal effect of various metabolic traits, lifestyle factors, and drug targets on liver fat. The findings complement existing epidemiological associations, further provide mechanistic insight, and potentially supports a role for drug interventions in reducing the burden of hepatic steatosis and related disease. Further clinical study is now warranted to investigate the relevance of these genetic analyses for patient care.
Zhang Z, Wang M, Gill D, et al., 2022, Genetically Predicted Smoking and Alcohol Consumption and Functional Outcome After Ischemic Stroke, NEUROLOGY, Vol: 99, Pages: E2693-E2698, ISSN: 0028-3878
Soremekun O, Slob EAW, Burgess S, et al., 2022, Genetically Predicted Lipid Traits, Diabetes Liability, and Carotid Intima-Media Thickness in African Ancestry Individuals: A Mendelian Randomization Study, CIRCULATION-GENOMIC AND PRECISION MEDICINE, Vol: 15, Pages: 608-610, ISSN: 2574-8300
Gill D, Pan Y, Lash JP, et al., 2022, Revisiting the Effects of Blood Pressure on Kidney Function: New Insights From a Mendelian Randomization Analysis, HYPERTENSION, Vol: 79, Pages: 2682-2684, ISSN: 0194-911X
Dib M-J, Ahmadi KR, Zagkos L, et al., 2022, Associations of genetically predicted vitamin B12 status across the pohenome, Nutrients, Vol: 14, ISSN: 2072-6643
Variation in vitamin B12 levels has been associated with a range of diseases across the life-course, the causal nature of which remains elusive. We aimed to interrogate genetically predicted vitamin B12 status in relation to a plethora of clinical outcomes available in the UK Biobank. Genome-wide association study (GWAS) summary data obtained from a Danish and Icelandic cohort of 45,576 individuals were used to identify 8 genetic variants associated with vitamin B12 levels, serving as genetic instruments for vitamin B12 status in subsequent analyses. We conducted a Mendelian randomisation (MR)-phenome-wide association study (PheWAS) of vitamin B12 status with 945 distinct phenotypes in 439,738 individuals from the UK Biobank using these 8 genetic instruments to proxy alterations in vitamin B12 status. We used external GWAS summary statistics for replication of significant findings. Correction for multiple testing was taken into consideration using a 5% false discovery rate (FDR) threshold. MR analysis identified an association between higher genetically predicted vitamin B12 status and lower risk of vitamin B deficiency (including all B vitamin deficiencies), serving as a positive control outcome. We further identified associations between higher genetically predicted vitamin B12 status and a reduced risk of megaloblastic anaemia (OR = 0.35, 95% CI: 0.20–0.50) and pernicious anaemia (0.29, 0.19–0.45), which was supported in replication analyses. Our study highlights that higher genetically predicted vitamin B12 status is potentially protective of risk of vitamin B12 deficiency associated with pernicious anaemia diagnosis, and reduces risk of megaloblastic anaemia. The potential use of genetically predicted vitamin B12 status in disease diagnosis, progression and management remains to be investigated.
Xie J, Prats-Uribe A, Maranon MG, et al., 2022, Genetic risk and incident venous thromboembolism in middle-aged and older adults following COVID-19 vaccination, JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Vol: 20, Pages: 2887-2895, ISSN: 1538-7933
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Ryan DK, Karhunen V, Su B, et al., 2022, Genetic evidence for protective effects of angiotensin converting enzyme against Alzheimer's disease but not other neurodegenerative diseases in European populations, Neurology Genetics, Vol: 8, ISSN: 2376-7839
Background and Objectives: Angiotensin-converting enzyme (ACE) inhibitors are a commonly prescribed class of medication used to treat heart failure, hypertension, and chronic kidney disease. However, previous observational studies have shown conflicting directions of associations between ACE inhibitors and risk of Alzheimer disease. Genetic evidence has supported a protective effect of cerebral ACE against Alzheimer disease (AD). However, it is unclear whether this effect is mediated through blood pressure and extends to other neurodegenerative diseases.Methods: We performed genetic colocalization investigating an effect of cortical ACE expression on AD risk in people of European ancestry. We further investigated whether any effect of ACE expression on AD risk is mediated through changes in blood pressure and whether effects extend to Parkinson disease, small-vessel disease, or cognitive function in a Mendelian randomization paradigm.Results: There was genetic evidence supporting a protective effect of cortical ACE expression on AD risk in people of European ancestry. Although higher cortical ACE expression was associated with higher blood pressure, there was no strong evidence to support that its association with AD was mediated through blood pressure nor that ACE expression affected risk of other neurodegenerative traits.Discussion: Genetic evidence supports protective effects of cerebral ACE expression on AD, but not other neurodegenerative outcomes in people of European ancestry. Further work is required to investigate whether therapeutic inhibition of ACE increases risk of Alzheimer disease.
Yuan S, Karhunen V, Larsson S, et al., 2022, Anthropometric Traits and Risk of Mitral Valve Prolapse: A Mendelian Randomization Study, CIRCULATION-GENOMIC AND PRECISION MEDICINE, Vol: 15, Pages: 473-475, ISSN: 2574-8300
Ardissino M, Rajasundaram S, Reddy R, et al., 2022, Safety of beta-blocker and calcium channel blocker antihypertensive drugs in pregnancy: a Mendelian randomization study, BMC Medicine, Vol: 20, ISSN: 1741-7015
Background: Beta-blocker (BB) and calcium channel blocker (CCB)antihypertensive drugs are commonly used in pregnancy. However, data on theirrelative impact on maternal and fetal outcomes are limited. We leveraged geneticvariants mimicking BB and CCB antihypertensive drugs to investigate their effects onrisk of pre-eclampsia, gestational diabetes and birthweight using the Mendelianrandomization paradigm.Methods: Genetic association estimates for systolic blood pressure (SBP) wereextracted from summary data of a genome-wide association study (GWAS) on757,601 participants. Uncorrelated single-nucleotide polymorphisms (SNPs)associated with SBP (p<5x10-8) in BB and CCB drug target gene regions wereselected as proxies for drug target perturbation. Genetic association estimates forthe outcomes were extracted from GWASs on 4,743 cases and 136,325 controls(women without a hypertensive disorder in pregnancy) for pre-eclampsia oreclampsia, 7,676 cases and 130,424 controls (women without any pregnancy-relatedmorbidity) for gestational diabetes, and 155,202 women (who have given birth atleast once) for birthweight of the first child. All studies were in European ancestrypopulations. Mendelian randomization estimates were generated using the twosample inverse-variance weighted model.Results: Although not reaching the conventional threshold for statistical significance,genetically-proxied BB was associated with reduced risk of pre-eclampsia (OR per10mmHg SBP reduction 0.27, 95%CI 0.06-1.19, p=0.08) and increased risk ofgestational diabetes (OR per 10mmHg SBP reduction 2.01, 95%CI 0.91-4.42,p=0.08), and significantly associated with lower birthweight of first child (beta per 10mmHg SBP reduction -0.27, 95%CI -0.39 to -0.15, p=1.90x10-5). Geneticallyproxied CCB was associated with reduced risk of pre-eclampsia and eclampsia (OR0.62, 95%CI 0.43-0.89, p=9.33x10-3), and was not associated with gestationaldiabetes (OR 1.05, 95% CI 0.76-1.45, p=0.76) or changes in birthweight of first
Giontella A, Lotta LA, Baras A, et al., 2022, Calcium, Its Regulatory Hormones, and Their Causal Role on Blood Pressure: A Two-Sample Mendelian Randomization study, JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM, Vol: 107, Pages: 3080-3085, ISSN: 0021-972X
Cohen JB, Mitchell GF, Gill D, et al., 2022, Arterial Stiffness and Diabetes Risk in Framingham Heart Study and UK Biobank, CIRCULATION RESEARCH, Vol: 131, Pages: 545-554, ISSN: 0009-7330
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Woolf B, Zagkos L, Gill D, 2022, TwoStepCisMR: A Novel Method and R Package for Attenuating Bias in cis-Mendelian Randomization Analyses, GENES, Vol: 13
Xie J, Strauss VY, Prats-Uribe A, et al., 2022, Genetic risk and incident venous thromboembolism in middle-aged and older adults following COVID-19 vaccination, PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Vol: 31, Pages: 118-118, ISSN: 1053-8569
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