scholarly journals Association of 25 Hydroxyvitamin D Concentration with Risk of COVID-19: A Mendelian Randomization Study

2020 ◽  
Author(s):  
Di Liu ◽  
Qiuyue Tian ◽  
Jie Zhang ◽  
Haifeng Hou ◽  
Wei Wang ◽  
...  
Keyword(s):  
Causal Relationship ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Causal Association ◽  
Hydroxyvitamin D ◽  
Increased Risk ◽  
25Ohd Concentration ◽  
25 Hydroxyvitamin D

Abstract Background: Coronavirus disease 2019 (COVID-19) has caused a large global pandemic. In observational studies, 25 hydroxyvitamin D (25OHD) concentration has been associated with an increased risk of Coronavirus disease 2019 (COVID-19). However, it remains unclear whether this association is causal.Methods: We performed a two-sample Mendelian randomization (MR) to explore the causal relationship between 25OHD concentration and COVID-19, using summary data from the genome-wide association studies (GWASs) and using 25OHD concentration-related SNPs as instrumental variables (IVs). Results: MR analysis did not show any evidence of a causal association of 25OHD concentration with COVID-19 susceptibility and severity (odds ratio [OR]=1.136, 95% confidence interval [CI] 0.988-1.306, P=0.074; OR=0.889, 95% CI 0.549-1.439, P=0.632). Sensitivity analyses using different instruments and statistical models yielded similar findings, suggesting the robustness of the causal association. No obvious pleiotropy bias and heterogeneity were observed.Conclusions: The MR analysis showed that there might be no linear causal relationship of 25OHD concentration with COVID-19 susceptibility and severity.

scholarly journals Association of 25 hydroxyvitamin D concentration with risk of COVID-19: a Mendelian randomization study

2020 ◽  
Author(s):  
Di Liu ◽  
Qiuyue Tian ◽  
Jie Zhang ◽  
Haifeng Hou ◽  
Wei Wang ◽  
...  
Keyword(s):  
Causal Relationship ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Causal Association ◽  
Hydroxyvitamin D ◽  
Increased Risk ◽  
25Ohd Concentration ◽  
25 Hydroxyvitamin D

Background In observational studies, 25 hydroxyvitamin D (25OHD) concentration has been associated with an increased risk of Coronavirus disease 2019 (COVID-19). However, it remains unclear whether this association is causal. Methods We performed a two-sample Mendelian randomization (MR) to explore the causal relationship between 25OHD concentration and COVID-19, using summary data from the genome-wide association studies (GWASs) and using 25OHD concentration-related SNPs as instrumental variables (IVs). Results MR analysis did not show any evidence of a causal association of 25OHD concentration with COVID-19 susceptibility and severity (odds ratio [OR]=1.136, 95% confidence interval [CI] 0.988-1.306, P=0.074; OR=0.889, 95% CI 0.549-1.439, P=0.632). Sensitivity analyses using different instruments and statistical models yielded similar findings, suggesting the robustness of the causal association. No obvious pleiotropy bias and heterogeneity were observed. Conclusion The MR analysis showed that there might be no linear causal relationship of 25OHD concentration with COVID-19 susceptibility and severity.

scholarly journals Leukocyte telomere length and amyotrophic lateral sclerosis: a Mendelian randomization study

2021 ◽  
Author(s):  
Kailin Xia ◽  
Linjing Zhang ◽  
Gan Zhang ◽  
Yajun Wang ◽  
Tao Huang ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Telomere Length ◽  
Causal Relationship ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Leukocyte Telomere Length ◽  
Weighted Median ◽  
Lateral Sclerosis

Abstract Background Observational studies have suggested that telomere length is associated with amyotrophic lateral sclerosis (ALS). However, it remains unclear whether this association is causal. We employed a two-sample Mendelian randomization (MR) approach to explore the causal relationship between leukocyte telomere length (LTL) and ALS based on the most cited and most recent and largest LTL genome-wide association studies (GWASs) that measured LTL with the Southern blot method (n = 9190) and ALS GWAS summary data (n = 80,610). We adopted the inverse variance weighted (IVW) method to examine the effect of LTL on ALS and used the weighted median method, simple median method, MR Egger method and MR PRESSO method to perform sensitivity analyses. Results We found that genetically determined longer LTL was inversely associated with the risk of ALS (OR = 0.846, 95% CI: 0.744–0.962, P = 0.011), which was mainly driven by rs940209 in the OBFC1 gene, suggesting a potential effect of OBFC1 on ALS. In sensitivity analyses, that was confirmed in MR Egger method (OR = 0.647,95% CI = 0.447–0.936, P = 0.050), and a similar trend was shown with the weighted median method (OR = 0.893, P = 0.201) and simple median method (OR = 0.935 P = 0.535). The MR Egger analyses did not suggest directional pleiotropy, showing an intercept of 0.025 (P = 0.168). Neither the influence of instrumental outliers nor heterogeneity was found. Conclusions Our results suggest that genetically predicted longer LTL has a causal relationship with a lower risk of ALS and underscore the importance of protecting against telomere loss in ALS.

scholarly journals Childhood obesity and multiple sclerosis: A Mendelian randomization study

2021 ◽  
pp. 135245852110017
Author(s):  
Adil Harroud ◽  
Ruth E Mitchell ◽  
Tom G Richardson ◽  
John A Morris ◽  
Vincenzo Forgetta ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Childhood Obesity ◽  
Mendelian Randomization ◽  
Pubertal Timing ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Uk Biobank ◽  
Increased Risk ◽  
Age At Puberty

Background: Higher childhood body mass index (BMI) has been associated with an increased risk of multiple sclerosis (MS). Objective: To evaluate whether childhood BMI has a causal influence on MS, and whether this putative effect is independent from early adult obesity and pubertal timing. Methods: We performed Mendelian randomization (MR) using summary genetic data on 14,802 MS cases and 26,703 controls. Large-scale genome-wide association studies provided estimates for BMI in childhood ( n = 47,541) and adulthood ( n = 322,154). In multivariable MR, we examined the direct effects of each timepoint and further adjusted for age at puberty. Findings were replicated using the UK Biobank ( n = 453,169). Results: Higher genetically predicted childhood BMI was associated with increased odds of MS (odds ratio (OR) = 1.26/SD BMI increase, 95% confidence interval (CI): 1.07–1.50). However, there was little evidence of a direct effect after adjusting for adult BMI (OR = 1.03, 95% CI: 0.70–1.53). Conversely, the effect of adult BMI persisted independent of childhood BMI (OR = 1.43; 95% CI: 1.01–2.03). The addition of age at puberty did not alter the findings. UK Biobank analyses showed consistent results. Sensitivity analyses provided no evidence of pleiotropy. Conclusion: Genetic evidence supports an association between childhood obesity and MS susceptibility, mediated by persistence of obesity into early adulthood but independent of pubertal timing.

scholarly journals Causal Association of Trauma With Subsequent Psychiatric Disorder: A Mendelian Randomization Study

2021 ◽  
Author(s):  
Dongqing Gu ◽  
Shan Ou ◽  
Guodong Liu
Keyword(s):  
Psychiatric Disorder ◽  
Mood Disorder ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Causal Association ◽  
Post Traumatic Stress ◽  
Mendelian Randomization Analysis ◽  
Increased Risk ◽  
Randomization Analysis

Abstract Objective Trauma has been proposed as a risk factor for the development of psychiatric disorder. This study aimed to determine the causal association between them. Methods Two-sample Mendelian randomization analyses were performed to estimate the causal association between trauma and psychiatric disorder. We obtained summary-level data for genetic variants associated with trauma and the corresponding association with psychiatric disorder from previous genome-wide association studies, and inverse variance weighted was used as the main method in our Mendelian randomization analysis. Results Genetically predisposed trauma was associated with an increased risk of psychiatric disorder (odds ratio [OR] = 1.02, 95% confidence interval [CI], 1.01–1.02,), mood disorder (OR = 1.01, 95% CI, 1.00-1.01) and depression (OR = 1.02, 95% CI, 1.01–1.02) in UK Biobank, as well as increased risk of mood disorder (OR = 1.23, 95% CI, 1.03–1.48), depression (OR = 1.10, 95% CI, 1.04–1.17), bipolar disorder (OR = 1.24, 95% CI, 1.04–1.49) and schizophrenia (OR = 1.47, 95% CI, 1.21–1.78) in data source from MR Base. However, Mendelian randomization evidence did not support an association between trauma and risk of post-traumatic stress disorder, anxiety disorder, sleep disorder, and eating disorder. Conclusions Findings from our Mendelian randomization analysis suggested that trauma might be causally associated with an increased risk of some common psychiatric disorder such as depression.

scholarly journals Association of Thyroid Function with Blood Pressure and Cardiovascular Disease: A Mendelian Randomization

2021 ◽  
Vol 11 (12) ◽  
pp. 1306
Author(s):  
Alice Giontella ◽  
Luca A. Lotta ◽  
John D. Overton ◽  
Aris Baras ◽  
Andrea Sartorio ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Blood Pressure ◽  
Thyroid Function ◽  
Lower Risk ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Thyroid Peroxidase ◽  
Genome Wide Association Studies ◽  
Causal Association

Thyroid function has a widespread effect on the cardiometabolic system. However, the causal association between either subclinical hyper- or hypothyroidism and the thyroid hormones with blood pressure (BP) and cardiovascular diseases (CVD) is not clear. We aim to investigate this in a two-sample Mendelian randomization (MR) study. Single nucleotide polymorphisms (SNPs) associated with thyroid-stimulating hormone (TSH), free tetraiodothyronine (FT4), hyper- and hypothyroidism, and anti-thyroid peroxidase antibodies (TPOAb), from genome-wide association studies (GWAS), were selected as MR instrumental variables. SNPs–outcome (BP, CVD) associations were evaluated in a large-scale cohort, the Malmö Diet and Cancer Study (n = 29,298). Causal estimates were computed by inverse-variance weighted (IVW), weighted median, and MR-Egger approaches. Genetically increased levels of TSH were associated with decreased systolic BP and with a lower risk of atrial fibrillation. Hyperthyroidism and TPOAb were associated with a lower risk of atrial fibrillation. Our data support a causal association between genetically decreased levels of TSH and both atrial fibrillation and systolic BP. The lack of significance after Bonferroni correction and the sensitivity analyses suggesting pleiotropy, should prompt us to be cautious in their interpretation. Nevertheless, these findings offer mechanistic insight into the etiology of CVD. Further work into the genes involved in thyroid functions and their relation to cardiovascular outcomes may highlight pathways for targeted intervention.

scholarly journals Mendelian randomization analysis revealed causal effects from gut microbiota to abdominal obesity

2020 ◽  
Author(s):  
Qian Xu ◽  
Shan-Shan Zhang ◽  
Yu-Fang Pei ◽  
Jing-Jing Ni ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Causal Relationship ◽  
Abdominal Obesity ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Summary Statistics ◽  
Replication Sample ◽  
Discovery Sample ◽  
Increased Risk

ABSTRACTAlthough recent studies have revealed the association between the gut microbiota and obesity, the causality remains elusive. We performed a Mendelian Randomization (MR) analysis to determine whether there is a causal relationship between gut microbiota and abdominal obesity. We used a two-sample MR approach to assess the causal effect from gut microbiota to obesity based on genome-wide association studies (GWAS) summary statistics. The GWAS summary statistics of gut microbiota obtained from UK-twins cohort (N=1,126) were used as discovery sample exposure, and the GWAS summary statistics from the Genetic Environmental Microbial (GEM) project (N=1,098) were used as replication sample exposure. Trunk fat mass (TFM) summary statistics from the UK Biobank (UKB) cohort (N=330,762) were used as outcome. Bacteria were grouped into taxa features at family level. A total of 16 families were analyzed in the discovery sample. Family Barnesiellaceae was associated with TFM at the nominal significance level (b=-3.81×10−4, P=1.96×10−3). The causal association was successfully replicated in the replication sample (b=-7.34×10−3, P =2.77×10−2). Our findings provided evidence of causal relationship from microbiota to fat development, and may be helpful in selecting potential causal bacteria for manipulating candidate gut microbiota to therapy obesity.IMPORTANCEObesity, as a global public health problem, is one of the most important risk factors contributing to the overall global burden of disease, and is associated with an increased risk of cardiovascular disease, type 2 diabetes, and certain cancers. Recent studies have shown that gut microbiota is closely related to the development of obesity, but the causal relationship is unclear. Therefore, it is necessary to identify the causality between gut microbiota and obesity. The significance of our research is in identifying the causal relationship from specific bacteria to fat development, which will provide the new insights into the microbiota mediated the fat development mechanism.

scholarly journals Genetic Evidence That Carbohydrate-Stimulated Insulin Secretion Leads to Obesity

2018 ◽  
Vol 64 (1) ◽  
pp. 192-200 ◽  
Author(s):  
Christina M Astley ◽  
Jennifer N Todd ◽  
Rany M Salem ◽  
Sailaja Vedantam ◽  
Cara B Ebbeling ◽  
...  
Keyword(s):  
Body Weight ◽  
Insulin Secretion ◽  
Causal Relationship ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
European Ancestry ◽  
Oral Glucose ◽  
Genome Wide Association Studies ◽  
Genetically Determined

Abstract BACKGROUND A fundamental precept of the carbohydrate–insulin model of obesity is that insulin secretion drives weight gain. However, fasting hyperinsulinemia can also be driven by obesity-induced insulin resistance. We used genetic variation to isolate and estimate the potentially causal effect of insulin secretion on body weight. METHODS Genetic instruments of variation of insulin secretion [assessed as insulin concentration 30 min after oral glucose (insulin-30)] were used to estimate the causal relationship between increased insulin secretion and body mass index (BMI), using bidirectional Mendelian randomization analysis of genome-wide association studies. Data sources included summary results from the largest published metaanalyses of predominantly European ancestry for insulin secretion (n = 26037) and BMI (n = 322154), as well as individual-level data from the UK Biobank (n = 138541). Data from the Cardiology and Metabolic Patient Cohort study at Massachusetts General Hospital (n = 1675) were used to validate genetic associations with insulin secretion and to test the observational association of insulin secretion and BMI. RESULTS Higher genetically determined insulin-30 was strongly associated with higher BMI (β = 0.098, P = 2.2 × 10−21), consistent with a causal role in obesity. Similar positive associations were noted in sensitivity analyses using other genetic variants as instrumental variables. By contrast, higher genetically determined BMI was not associated with insulin-30. CONCLUSIONS Mendelian randomization analyses provide evidence for a causal relationship of glucose-stimulated insulin secretion on body weight, consistent with the carbohydrate–insulin model of obesity.

scholarly journals Sleep, major depressive disorder, and Alzheimer disease

Neurology ◽  
2020 ◽  
Vol 95 (14) ◽  
pp. e1963-e1970 ◽  
Author(s):  
Jian Huang ◽  
Verena Zuber ◽  
Paul M. Matthews ◽  
Paul Elliott ◽  
Joanna Tzoulaki ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Alzheimer Disease ◽  
Depressive Disorder ◽  
Causal Relationship ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Sleep Patterns ◽  
Major Depressive

ObjectiveTo explore the causal relationships between sleep, major depressive disorder (MDD), and Alzheimer disease (AD).MethodsWe conducted bidirectional 2-sample Mendelian randomization analyses. Genetic associations were obtained from the largest genome-wide association studies currently available in UK Biobank (n = 446,118), Psychiatric Genomics Consortium (n = 18,759), and International Genomics of Alzheimer's Project (n = 63,926). We used the inverse variance–weighted Mendelian randomization method to estimate causal effects and weighted median and Mendelian randomization–Egger for sensitivity analyses to test for pleiotropic effects.ResultsWe found that higher risk of AD was significantly associated with being a “morning person” (odds ratio [OR] 1.01, p = 0.001), shorter sleep duration (self-reported: β = −0.006, p = 1.9 × 10−4; accelerometer based: β = −0.015, p = 6.9 × 10−5), less likely to report long sleep (β = −0.003, p = 7.3 × 10−7), earlier timing of the least active 5 hours (β = −0.024, p = 1.7 × 10−13), and a smaller number of sleep episodes (β = −0.025, p = 5.7 × 10−14) after adjustment for multiple comparisons. We also found that higher risk of AD was associated with lower risk of insomnia (OR 0.99, p = 7 × 10−13). However, we did not find evidence that these abnormal sleep patterns were causally related to AD or for a significant causal relationship between MDD and risk of AD.ConclusionWe found that AD may causally influence sleep patterns. However, we did not find evidence supporting a causal role of disturbed sleep patterns for AD or evidence for a causal relationship between MDD and AD.

scholarly journals Mendelian randomization highlights insomnia as a risk factor for pain diagnoses

SLEEP ◽  
2021 ◽  
Author(s):  
Martin Broberg ◽  
Juha Karjalainen ◽  
Hanna M Ollila ◽  
Keyword(s):  
Mendelian Randomization ◽  
Clinical Investigation ◽  
Association Studies ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Study Objective ◽  
Increased Risk ◽  
Icd 10 ◽  
Chronic Pain Conditions ◽  
Insomnia Symptoms

Abstract Study objective Insomnia has been linked to acute and chronic pain conditions; however, it is unclear whether such relationships are causal. Recently, a large number of genetic variants have been discovered for both insomnia and pain through genome-wide association studies (GWAS) providing a unique opportunity to examine evidence for causal relationships through the use of the Mendelian randomization paradigm. Methods To elucidate the causality between insomnia and pain we performed bidirectional Mendelian randomization analysis in FinnGen, where clinically diagnosed ICD-10 categories of pain had been evaluated. In addition, we used measures of self-reported insomnia symptoms. We used endpoints for pain in the FinnGen Release 5 (R5) (N=218,379), and a non-overlapping sample for insomnia (UK Biobank (UKBB) and 23andMe, N=1,331,010 or UKBB alone N=453,379). We assessed robustness of results through conventional MR sensitivity analyses. Results Genetic liability to insomnia symptoms increased the odds of reporting pain (odds ratio (OR) [95% confidence interval (CI)] = 1.47 [1.38–1.58], P = 4.12x10 -28). Manifested pain had a small effect on increased risk for insomnia (OR [95% CI] = 1.04 [1.01–1.07], P < 0.05). Results were consistent in sensitivity analyses. Conclusions Our findings support a bidirectional causal relationship between insomnia and pain. These data support further clinical investigation into the utility of insomnia treatment as a strategy for pain management and vice versa.

scholarly journals Circulating Vitamin D Levels and Risk of Vitiligo: Evidence From Meta-Analysis and Two-Sample Mendelian Randomization

2021 ◽  
Vol 8 ◽  
Author(s):  
Jie Song ◽  
Ke Liu ◽  
Weiwei Chen ◽  
Bin Liu ◽  
Hong Yang ◽  
...  
Keyword(s):  
Vitamin D ◽  
Observational Studies ◽  
Mendelian Randomization ◽  
Meta Analysis ◽  
Sensitivity Analyses ◽  
Genome Wide Association Studies ◽  
Hydroxyvitamin D ◽  
Vitamin D Levels ◽  
Significant Difference ◽  
25 Hydroxyvitamin D

Background: The association between circulating vitamin D levels and risk of vitiligo was inconsistent among observational studies, and whether these observed associations were causal remained unclear. Therefore, we aimed to evaluate the effect of vitamin D on the risk of vitiigo using meta-analysis and Mendelian randomization (MR).Methods: At the meta-analysis stage, literature search was performed in PubMed and Web of Science to identify eligible observational studies examining the association of circulating 25-hydroxyvitamin D [25(OH)D] or 25-hydroxyvitamin D3 [25(OH)D3] levels with risk of vitiligo up to April 30, 2021. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) of 25(OH)D and 25(OH)D3 in patients with vitiligo relative to controls were pooled. Then at the MR stage, genetic instruments for circulating 25(OH)D (N = 120,618) and 25(OH)D3 (N = 40,562) levels were selected from a meta-analysis of genome-wide association studies (GWAS) of European descent, and summary statistics of vitiligo were obtained from a meta-analysis of three GWASs including 4,680 cases and 39,586 controls. We used inverse-variance weighted (IVW) as main method, followed by weighted-median and likelihood-based methods. Pleiotropic and outlier variants were assessed by MR-Egger regression and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test.Results: In the meta-analysis, patients with vitiligo had a lower level of circulating 25(OH)D compared with controls [SMD = −1.40; 95% confidence interval (CI): −1.91, −0.89; P < 0.001], while no statistically significant difference of 25(OH)D3 between vitiligo cases and controls was found (SMD = −0.63; 95% CI: −1.29, 0.04; P = 0.064). However, in the MR analyses, genetically predicted 25(OH)D [odds ratio (OR) = 0.93, 95% CI = 0.66–1.31, P = 0.66] and 25(OH)D3 levels (OR = 0.95, 95% CI = 0.80–1.14, P = 0.60) had null associations with risk of vitiligo using the IVW method. Sensitivity analyses using alternative MR methods and instrumental variables (IV) sets obtained consistent results, and no evidence of pleiotropy or outliers was observed.Conclusion: Our study provided no convincing evidence for a causal effect of 25(OH)D or 25(OH)D3 levels on the risk of vitiligo. Further longitudinal and experimental studies, as well as functional studies are warranted to elucidate the role of vitamin D in the development of vitiligo.

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