scholarly journals Cannabis use and risk of schizophrenia: a Mendelian randomization study

2016 ◽  
Author(s):  
Julien Vaucher ◽  
Brendan J. Keating ◽  
Aurélie M. Lasserre ◽  
Wei Gan ◽  
Donald M. Lyall ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Mendelian Randomization ◽  
Cannabis Use ◽  
Sensitivity Analyses ◽  
P Value ◽  
Tobacco Exposure ◽  
Increased Risk ◽  
Show Evidence ◽  
Public Health Message ◽  
Genetically Determined

ABSTRACTCannabis use is observationally associated with an increased risk of schizophrenia, however whether the relationship is causal is not known. To determine the nature of the association between cannabis use on risk of schizophrenia using Mendelian randomization (MR) analysis, we used ten genetic variants previously identified to associate with cannabis use in 32,330 individuals. Genetic variants were used in a MR analyses of the association of genetically determined cannabis on risk of schizophrenia in 34,241 cases and 45,604 controls from predominantly European descent. Estimates from MR were compared to a metaanalysis of observational studies reporting effect estimates for ever use of cannabis and risk of schizophrenia or related disorders. Genetically determined use of cannabis was associated with increased risk of schizophrenia (OR of schizophrenia for users vs. non-users of cannabis: 1.37; 95%CI, 1.09 to 1.67; P-value=0.007). The corresponding estimate from observational analysis was 1.50 (95% CI, 1.10 to 2.00; P-value for heterogeneity = 0.88). The genetic instrument did not show evidence of pleiotropy on MR-Egger (Egger test, P-value=0.292) nor on multivariable MR accounting for tobacco exposure (OR of schizophrenia for users vs. nonusers of cannabis, adjusted for ever vs. never smoker: 1.41; 95% CI, 1.09-1.83). Furthermore, the causal estimate remained robust to sensitivity analyses. These findings strongly support a causal association between genetically determined use of cannabis and risk of schizophrenia. Such robust evidence may inform public health message about the risks of cannabis use, especially regarding its potential mental health consequences.

scholarly journals Genetically Determined Physical Activity and Its Association with Circulating Blood Cells

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 908 ◽  
Author(s):  
Femke M. Prins ◽  
M. Abdullah Said ◽  
Yordi J. van de Vegte ◽  
Niek Verweij ◽  
Hilde E. Groot ◽  
...  
Keyword(s):  
Physical Activity ◽  
Blood Cells ◽  
Fixed Effects ◽  
Mendelian Randomization ◽  
P Value ◽  
Nucleotide Polymorphisms ◽  
Increased Risk ◽  
Inflammatory State ◽  
The Uk ◽  
Genetically Determined

Lower levels of physical activity (PA) have been associated with increased risk of cardiovascular disease. Worldwide, there is a shift towards a lifestyle with less PA, posing a serious threat to public health. One of the suggested mechanisms behind the association between PA and disease development is through systemic inflammation, in which circulating blood cells play a pivotal role. In this study we investigated the relationship between genetically determined PA and circulating blood cells. We used 68 single nucleotide polymorphisms associated with objectively measured PA levels to perform a Mendelian randomization analysis on circulating blood cells in 222,645 participants of the UK Biobank. For inverse variance fixed effects Mendelian randomization analyses, p < 1.85 × 10−3 (Bonferroni-adjusted p-value of 0.05/27 tests) was considered statistically significant. Genetically determined increased PA was associated with decreased lymphocytes (β = –0.03, SE = 0.008, p = 1.35 × 10−3) and decreased eosinophils (β = –0.008, SE = 0.002, p = 1.36 × 10−3). Although further mechanistic studies are warranted, these findings suggest increased physical activity is associated with an improved inflammatory state with fewer lymphocytes and eosinophils.

scholarly journals Cannabis Use and the Risk of Cardiovascular Diseases: A Mendelian Randomization Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Jianqiang Zhao ◽  
Heng Chen ◽  
Chengui Zhuo ◽  
Shudong Xia
Keyword(s):  
Body Mass Index ◽  
Cardiovascular Diseases ◽  
Body Mass ◽  
Tobacco Use ◽  
Mendelian Randomization ◽  
Causal Effect ◽  
Cannabis Use ◽  
Sensitivity Analyses ◽  
Nucleotide Polymorphisms ◽  
Genetically Determined

Several observational studies have shown that cannabis use has negative effects on the cardiovascular system, but the causality of this relationship has not been confirmed. The aim of the current study was to estimate the effects of genetically determined cannabis use on risk of cardiovascular diseases. Ten single-nucleotide polymorphisms related to cannabis use were employed as instruments to estimate the association between genetically determined cannabis use and risk of cardiovascular diseases using a two-sample Mendelian randomization (MR) method. Summary statistics data on exposure and outcomes were obtained from different genome-wide association meta-analysis studies. The results of this MR analysis showed no causal effects of cannabis use on the risk of several common cardiovascular diseases, including coronary artery disease, myocardial infarction, stroke and ischemic stroke subtypes, atrial fibrillation (AF), and heart failure. Various sensitivity analyses yielded similar results, and no heterogeneity and directional pleiotropy were observed. After adjusting for tobacco use and body mass index, multivariable MR analysis suggested a causal effect of cannabis use on small vessel stroke (SVS) [odds ratio (OR) 1.17; 95% CI 1.02–1.35; p = 0.03] and AF (OR 1.06; 95% CI 1.01–1.10; p = 0.01), respectively. This two-sample MR study did not demonstrate a causal effect of genetic predisposition to cannabis use on several common cardiovascular outcomes. After adjusting for tobacco use and body mass index, the multivariable MR analysis suggested a detrimental effect of cannabis use on the risk of SVS and AF, respectively.

scholarly journals Investigating causal pathways between liability to ADHD and substance use, and liability to substance use and ADHD risk, using Mendelian randomization

2019 ◽  
Author(s):  
Jorien L Treur ◽  
Ditte Demontis ◽  
George Davey Smith ◽  
Hannah Sallis ◽  
Tom G Richardson ◽  
...  
Keyword(s):  
Substance Use ◽  
Alcohol Use ◽  
Genetic Variants ◽  
Mendelian Randomization ◽  
Smoking Initiation ◽  
Cannabis Use ◽  
Causal Effects ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Causal Pathways

ABSTRACTBackgroundAttention-deficit hyperactivity disorder (ADHD) has consistently been associated with substance (ab)use, but the nature of this association is not fully understood. In view of preventive efforts, a vital question is whether there are causal effects, from ADHD to substance use and/or from substance use to ADHD.MethodsWe applied bidirectional Mendelian randomization using summary-level data from the largest available genome-wide association studies (GWASs) on ADHD, smoking (initiation, cigarettes/day, cessation, and a compound measure of lifetime smoking), alcohol use (drinks/week and alcohol use disorder), cannabis use (initiation and cannabis use disorder (CUD)) and coffee consumption (cups/day). Genetic variants robustly associated with the ‘exposure’ were selected as instruments and then identified in the ‘outcome’ GWAS. Effect estimates from individual genetic variants were combined with inverse-variance weighted regression and five sensitivity analyses were applied (weighted median, weighted mode, MR-Egger, generalized summary-data-based MR, and Steiger filtering).ResultsWe found strong evidence that liability to ADHD increases likelihood of smoking initiation and also cigarettes per day among smokers, decreases likelihood of smoking cessation, and increases likelihood of cannabis initiation and CUD. In the other direction, there was evidence that liability to smoking initiation and CUD increase ADHD risk. There was no clear evidence of causal effects between liability to ADHD and alcohol or caffeine consumption.ConclusionsWe find evidence for causal effects of liability to ADHD on smoking and cannabis use, and of liability to smoking and cannabis use on ADHD risk, indicating bidirectional pathways. Further work is needed to explore causal mechanisms.

scholarly journals Association of leukocyte telomere length with chronic kidney disease in East Asians with type 2 diabetes: A Mendelian randomization study

2021 ◽  
Author(s):  
Resham L Gurung ◽  
Rajkumar Dorajoo ◽  
Yiamunaa M ◽  
Ling Wang ◽  
Sylvia Liu ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Telomere Length ◽  
Mendelian Randomization ◽  
Random Effect ◽  
Leukocyte Telomere Length ◽  
Increased Risk ◽  
Genetically Determined

Abstract Background Chronic kidney disease (CKD) is common among type 2 diabetes (T2D) and increases the risk of kidney failure and cardiovascular diseases. Shorter leukocyte telomere length is associated with CKD in patients with T2D. We previously reported single nucleotide polymorphisms (SNPs) associated with leukocyte telomere length in Asian population. In this study, we elucidated the association of these SNPs with CKD in patients with T2D using Mendelian randomization (MR) approach. Methods The cross-sectional association of 16 leukocyte telomere length SNPs with CKD, defined as an estimated glomerular filtration rate of less than 60 ml/min/1.73m2 was assessed among 4,768 (1,628 cases, 3,140 controls) participants in the Singapore Study of Macro-angiopathy and Micro-vascular Reactivity in Type 2 Diabetes and Diabetic Nephropathy cohorts. MR analysis was performed using the random-effect inverse-variance weighted (IVW) method, the weighted median, MR-Egger and Radial MR adjusted for age and sex-stratified by cohorts and ethnicity (Chinese and Malays), then meta-analysed. Results Genetically determined shorter leukocyte telomere length was associated with increased risk of CKD in patients with T2D (meta-IVW adjusted odds ratio = 1.51 [95% confidence interval, 1.12 - 2.12; P = 0.007; Phet= 0.547]). Similar results were obtained following sensitivity analysis. MR-Egger analysis (intercept) suggested no evidence of horizontal pleiotropy (β  =  0.010, P = 0.751). Conclusions Our findings suggest that genetically determined leukocyte telomere length is associated with CKD in patients with T2D. Further studies are warranted to elucidate the causal role of telomere length in CKD progression.

scholarly journals Bias in two-sample Mendelian randomization when using heritable covariable-adjusted summary associations

2021 ◽  
Author(s):  
Fernando Pires Hartwig ◽  
Kate Tilling ◽  
George Davey Smith ◽  
Deborah A Lawlor ◽  
Maria Carolina Borges
Keyword(s):  
Waist Circumference ◽  
Genetic Variants ◽  
Mendelian Randomization ◽  
Causal Effect ◽  
Association Studies ◽  
Real Data ◽  
Sensitivity Analyses ◽  
Effect Estimate ◽  
Genome Wide Association Studies ◽  
Residual Confounding

Abstract Background Two-sample Mendelian randomization (MR) allows the use of freely accessible summary association results from genome-wide association studies (GWAS) to estimate causal effects of modifiable exposures on outcomes. Some GWAS adjust for heritable covariables in an attempt to estimate direct effects of genetic variants on the trait of interest. One, both or neither of the exposure GWAS and outcome GWAS may have been adjusted for covariables. Methods We performed a simulation study comprising different scenarios that could motivate covariable adjustment in a GWAS and analysed real data to assess the influence of using covariable-adjusted summary association results in two-sample MR. Results In the absence of residual confounding between exposure and covariable, between exposure and outcome, and between covariable and outcome, using covariable-adjusted summary associations for two-sample MR eliminated bias due to horizontal pleiotropy. However, covariable adjustment led to bias in the presence of residual confounding (especially between the covariable and the outcome), even in the absence of horizontal pleiotropy (when the genetic variants would be valid instruments without covariable adjustment). In an analysis using real data from the Genetic Investigation of ANthropometric Traits (GIANT) consortium and UK Biobank, the causal effect estimate of waist circumference on blood pressure changed direction upon adjustment of waist circumference for body mass index. Conclusions Our findings indicate that using covariable-adjusted summary associations in MR should generally be avoided. When that is not possible, careful consideration of the causal relationships underlying the data (including potentially unmeasured confounders) is required to direct sensitivity analyses and interpret results with appropriate caution.

scholarly journals Guidelines for performing Mendelian randomization investigations

2020 ◽  
Vol 4 ◽  
pp. 186 ◽  
Author(s):  
Stephen Burgess ◽  
George Davey Smith ◽  
Neil M. Davies ◽  
Frank Dudbridge ◽  
Dipender Gill ◽  
...  
Keyword(s):  
Statistical Methods ◽  
Genetic Variants ◽  
Mendelian Randomization ◽  
Data Sources ◽  
Sensitivity Analyses ◽  
Primary Analysis ◽  
Data Presentation ◽  
Journal Editors ◽  
Robust Statistical Methods

This paper provides guidelines for performing Mendelian randomization investigations. It is aimed at practitioners seeking to undertake analyses and write up their findings, and at journal editors and reviewers seeking to assess Mendelian randomization manuscripts. The guidelines are divided into nine sections: motivation and scope, data sources, choice of genetic variants, variant harmonization, primary analysis, supplementary and sensitivity analyses (one section on robust statistical methods and one on other approaches), data presentation, and interpretation. These guidelines will be updated based on feedback from the community and advances in the field. Updates will be made periodically as needed, and at least every 18 months.

scholarly journals Genetic Association of ERAP1 and ERAP2 With Eclampsia and Preeclampsia in Northeastern Brazilian Women

2021 ◽  
Author(s):  
LEONARDO CAPISTRANO FERREIRA ◽  
CARLOS EDUARDO MAIA GOMES ◽  
PRIYA DUGGAL ◽  
INGRID DE PAULA HOLANDA ◽  
AMANDA SAMARA DE LIMA ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Genetic Variants ◽  
Antigen Processing ◽  
P Value ◽  
Chronic Hypertension ◽  
Ang Ii ◽  
Small Peptides ◽  
Increased Risk ◽  
Genotype C ◽  
Risk Of Preeclampsia

Abstract The clinical spectrum of hypertensive disorders of pregnancy (HDP) is determined by the interplay between environmental and genetic factors, most of which remains unknown. ERAP1, ERAP2 and LNPEP genes code for multifunctional aminopeptidases involved with antigen processing and degradation of small peptides such as angiotensin II (Ang II), vasopressin and oxytocin. We aimed to test for associations between genetic variants in aminopeptidases and HDP. A total of 1282 pregnant women (normotensive controls, n=693; preeclampsia, n=342; chronic hypertension with superimposed preeclampsia, n=61; eclampsia, n=74; and HELLP syndrome, n=112) were genotyped for variants in LNPEP (rs27300, rs38034, rs2303138), ERAP1 (rs27044, rs30187) and ERAP2 (rs2549796 rs2927609 rs11135484). We also evaluated the effect of ERAP1 rs30187 on plasma Ang II levels in an additional cohort of 65 pregnant women. The genotype C/C, in ERAP1 rs30187 variant (c.1583T>C, p.Lys528Arg), was associated with increased risk of eclampsia (OR=1.85, p=0.019) whereas ERAP2 haplotype rs2549796(C)-rs2927609(C)-rs11135484(G) was associated with preeclampsia (OR=1.96, corrected p-value=0.01). Ang II plasma levels did not differ across rs30187 genotypic groups (p=0.895). In conclusion, ERAP1 gene is associated with eclampsia whereas ERAP2 is associated with preeclampsia, although the mechanism by which genetic variants in ERAPs influence the risk of preeclampsia and eclampsia remain to be elucidated.

scholarly journals Dietary Protein and Fat Intake Affects Diabetes Risk with CDKAL1 Genetic Variants in Korean Adults

2020 ◽  
Vol 21 (16) ◽  
pp. 5607
Author(s):  
Woo Jeong Choi ◽  
Hyun-Seok Jin ◽  
Sung-Soo Kim ◽  
Dayeon Shin
Keyword(s):  
Dietary Protein ◽  
Genetic Variants ◽  
Diabetes Risk ◽  
Dietary Factors ◽  
Regulatory Subunit ◽  
P Value ◽  
Fat Intake ◽  
Korean Adults ◽  
A Genome ◽  
Increased Risk

Cyclin-dependent kinase 5 regulatory subunit-associated protein 1-like 1 (CDKAL1) is one of the strongest diabetes loci identified to date; evidence suggests that it plays an important role in insulin secretion. Dietary factors that affect insulin demand might enhance the risk of diabetes associated with CDKAL1 variants. Our aim was to examine the interactions between dietary protein and fat intake and CDKAL1 genetic variants in relation to the risk of diabetes in Korean adults. Single nucleotide polymorphisms (SNPs) were selected with a genome-wide association study (GWAS) for diabetes after adjustment for age, gender, and examination site. Using data from the Health Examinees (HEXA) Study of the Korean Genome and Epidemiology Study (KoGES), 3988 middle-aged Korean adults between 40–76 years of age (2034 men and 1954 women) were included in the study. Finally, rs7756992 located within the CDKAL1 gene region was selected from GWAS (p-value < 5 × 10−8). Multivariable logistic regression models were used to evaluate the interactions between genotypes and dietary protein and fat intake in relation to diabetes risk after adjustment for age, gender, BMI, waist circumference, physical activity, smoking status, drinking habits, and examination site. Significant interactions between CDKAL1 rs7756992 and dietary protein and fat intake for the risk of diabetes were observed in men (p-value < 0.05). In women, significant interactions between dietary protein and fat intake and CDKAL1 variants (rs7756992) were associated with increased risk of diabetes (p-value < 0.05). Dietary protein and fat intake interacted differently with CDKAL1 variants in relation to the risk of diabetes in Korean adults of both genders. These findings indicate that CDKAL1 variants play a significant role in diabetes and that dietary protein and fat intake could affect these associations.

scholarly journals 3442 Among Hospitalized Patients, Cannabis use is Associated with Reduced risk of Clostridium Difficile infection

2019 ◽  
Vol 3 (s1) ◽  
pp. 33-34
Author(s):  
Adeyinka Charles Adejumo ◽  
Terence Ndonyi Bukong
Keyword(s):  
Clostridium Difficile ◽  
Clostridium Difficile Infection ◽  
Hospitalized Patients ◽  
Cannabis Use ◽  
Care Utilization ◽  
P Value ◽  
Adjusted Relative Risk ◽  
Increased Risk ◽  
The Impact ◽  
Reduced Risk

OBJECTIVES/SPECIFIC AIMS: Clostridium Difficile Infection (CDI), a prevalent cause of diarrhea, is the most notorious hospital-acquired infection, resulting in an alarming mortality and health care utilization rates. Herein, we investigate the impact of cannabis use, which is gaining significant legalization for recreational use, on the risk of CDI. METHODS/STUDY POPULATION: We selected adult records (age ≥ 18 years) from the Nationwide Inpatient Sample 2014, and identified cannabis users and other clinical conditions using ICD-9-CM codes. With multivariate logistic modeling, we generated propensity scores for cannabis users and matched them to non-users in a 1:1 ratio (104,936:104,936). We then estimated the adjusted relative risk (aRR) for having CDI using conditional Possion regression models with generalized estimating equations [SAS 9.4]. RESULTS/ANTICIPATED RESULTS: Among the matched hospitalizations (n=209,872), cannabis usage was associated with a reduced incidence of CDI (505.8[464.7-550.6] vs. 694.9[645.8-747.70] per 100,000 hospitalizations), resulting in a 27% reduced risk of CDI (aRR:0.73[0.65-0.81]; p-value:<0.0001). Non-dependent and dependent cannabis users respectively had 22% and 78% reduced likelihood of CDI when compared to non-cannabis users (0.78[0.69-0.90] & 0.22[0.12-0.40]). Furthermore, dependent users had less risk of CDI compared to non-dependent users (0.28[0.16-0.51]). Comparatively, abusive use of other substances like alcohol and tobacco was associated with increased risk for CDI (1.30[1.13-1.49] & 1.24[1.10-1.40]) DISCUSSION/SIGNIFICANCE OF IMPACT: Unlike alcohol and tobacco abuse which are associated with elevated risk for CDI, cannabis use, is related to a decreased risk of CDI amongst hospitalized patients. Further prospective and molecular mechanistic studies are required to elucidate how cannabis impacts CDI.

scholarly journals Association of 25-hydroxyvitamin D with cardiometabolic risk factors and metabolic syndrome: a mendelian randomization study

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Chi Chen ◽  
Yi Chen ◽  
Pan Weng ◽  
Fangzhen Xia ◽  
Qin Li ◽  
...  
Keyword(s):  
Risk Factors ◽  
Metabolic Syndrome ◽  
Vitamin D ◽  
Cardiometabolic Risk ◽  
Mendelian Randomization ◽  
Cardiometabolic Risk Factors ◽  
Metabolic Traits ◽  
Increased Risk ◽  
Vitamin D Levels ◽  
Genetically Determined

Abstract Background Low circulating vitamin D levels have been associated with increased risk of metabolic syndrome (MS) and cardiometabolic risk factors in multiple epidemiology studies. However, whether this association is causal is still unclear. We aimed to test whether genetically lowered vitamin D levels were associated with MS and its metabolic traits, using mendelian randomization (MR) methodology. Methods Ten thousand six hundred fifty-five participants were enrolled from the SPECT-China study, which was performed in 23 sites in East China during 2014 to 2016. Using four single-nucleotide polymorphisms (SNPs) in the DHCR7, CYP2R1, GC and CYP24A1 genes with known effects on 25(OH) D concentrations, we created a genetic risk score (GRS) as instrumental variable (IV) to estimate the effect of genetically lowered 25(OH) D on MS and cardiometabolic risk factors. MS was defined according to the International Diabetes Federation criteria. Results Lower measured 25(OH)D levels were associated with MS (OR 0.921, 95% CI 0.888, 0.954) after multivariable adjustment. However, the MR-derived odds ratio of genetically determined 25(OH) D for risk of MS was 0.977 (95% CI 0.966, 1.030). The MR-derived estimates for raised fasting plasma glucose was 0.578 (95% CI 0.321, 0.980) per 10 nmol/L GRSsynthesis determined increase of 25(OH) D levels. Conclusions We found no evidence that genetically determined reduction in 25(OH)D conferred an increased risk of MS and its metabolic traits. However, we created our GRS only on the basis of common variants, which represent limited amount of variance in 25(OH)D. MR studies using rare variants, and large-scale well-designed RCTs about the effect of vitamin D supplementation on MS are warranted to further validate the findings.

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