scholarly journals Investigating Causal Relations Between Circulating Metabolites and Alzheimer’s Diseases: A Mendelian Randomization Study

Author(s):  
Shu-Yi Huang ◽  
Yu-Xiang Yang ◽  
Ya-Ru Zhang ◽  
Kevin Kuo ◽  
Hong-Qi Li ◽  
...  

Abstract BackgroundMetabolomics is a promising approach that can be used to understand pathophysiological pathways of Alzheimer disease (AD). However, the relationships between metabolism and AD are poorly understood. The aim of this study is to investigate the causal association between circulating metabolites and risk of AD by combining metabolomics with genomics through two-sample Mendelian randomization (MR) approach.MethodsGenetic associations with 123 circulating metabolic traits were utilized as exposures. A large summary statistics data from International Genomics of Alzheimer’s Project was used in primary analysis, including 21,982 AD cases and 41,944 controls. Validation was further performed using family history of AD data from UK Biobank (27,696 cases of maternal AD, 14,338 cases of paternal AD and 272,244 controls). We utilized the inverse-variance weighted method as primary analysis and four additional MR methods (MR-Egger, weighted median, weighted mode, and MR pleiotropy residual sum and outlier) for sensitivity analyses.ResultsWe found one-fold increased risk of developing AD per standard deviation increase in the levels of circulating ApoB (odd ratio (OR)=3.18; 95% confidence interval (CI): 1.52–6.66, P=0.0022) and glycoprotein acetyls (OR=1.21; 95% CI: 1.05–1.39, P=0.0093), serum total cholesterol (OR=2.73; 95% CI: 1.41-5.30, P=0.0030), and low-density lipoprotein (LDL) cholesterol (OR=2.34; 95% CI: 1.53-3.57, P=0.0001). Whereas glutamine (OR=0.81; 95% CI: 0.71-0.92, P=0.0011) were significantly associated with lower risk of AD. We also detected causal effects of several different composition of LDL fractions on increased AD risk, which has been verified in validation. However, we found no association between circulating high-density lipoprotein cholesterol and AD.ConclusionsOur findings provided robust evidence supporting causal effects of circulating glycoprotein acetyls, ApoB, LDL cholesterol, and serum total cholesterol on higher risk of AD, whereas glutamine showed the protective effect. Further research is required to decipher the biological pathways underpinning associations.

2021 ◽  
Author(s):  
Shu-Yi Huang ◽  
Yu-Xiang Yang ◽  
Ya-Ru Zhang ◽  
Kevin Kuo ◽  
Hong-Qi Li ◽  
...  

Abstract BackgroundMetabolomics is a promising approach that can be used to understand pathophysiological pathways of Alzheimer disease (AD). However, the relationships between metabolism and AD are poorly understood. The aim of this study is to investigate the causal association between circulating metabolites and risk of AD by combining metabolomics with genomics through two-sample Mendelian randomization (MR) approach. MethodGenetic associations with 123 circulating metabolic traits were utilized as exposures. A large summary statistics data from International Genomics of Alzheimer’s Project was used in primary analysis, including 21,982 AD cases and 41,944 controls. Validation was further performed using family history of AD data from UK Biobank (27,696 cases of maternal AD, 14,338 cases of paternal AD and 272,244 controls). We utilized the inverse-variance weighted method as primary analysis and four additional MR methods (MR-Egger, weighted median, weighted mode, and MR pleiotropy residual sum and outlier) for sensitivity analyses. ResultsWe found one-fold increased risk of developing AD per standard deviation increase in the levels of circulating ApoB (odd ratio (OR)=3.18; 95% confidence interval (CI): 1.52–6.66, P=0.0022) and glycoprotein acetyls (OR=1.21; 95% CI: 1.05–1.39, P=0.0093), serum total cholesterol (OR=2.73; 95% CI: 1.41-5.30, P=0.0030), and low-density lipoprotein (LDL) cholesterol (OR=2.34; 95% CI: 1.53-3.57, P=0.0001). Whereas glutamine (OR=0.81; 95% CI: 0.71-0.92, P=0.0011) were significantly associated with lower risk of AD. We also detected causal effects of several different composition of LDL fractions on increased AD risk, which has been verified in validation. However, we found no association between circulating high-density lipoprotein cholesterol and AD. ConclusionsOur findings provided robust evidence supporting causal effects of circulating glycoprotein acetyls, ApoB, LDL cholesterol, and serum total cholesterol on higher risk of AD, whereas glutamine showed the protective effect. Further research is required to decipher the biological pathways underpinning associations.


2019 ◽  
Vol 49 (4) ◽  
pp. 1117-1131 ◽  
Author(s):  
Alicia Beeghly-Fadiel ◽  
Nikhil K Khankari ◽  
Ryan J Delahanty ◽  
Xiao-Ou Shu ◽  
Yingchang Lu ◽  
...  

Abstract Background Conventional epidemiologic studies have evaluated associations between circulating lipid levels and breast cancer risk, but results have been inconsistent. As Mendelian randomization analyses may provide evidence for causal inference, we sought to evaluate potentially unbiased associations between breast cancer risk and four genetically predicted lipid traits. Methods Previous genome-wide association studies (GWAS) have identified 164 discrete variants associated with high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), triglycerides and total cholesterol. We used 162 of these unique variants to construct weighted genetic scores (wGSs) for a total of 101 424 breast cancer cases and 80 253 controls of European ancestry from the Breast Cancer Association Consortium (BCAC). Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for associations between per standard deviation increase in genetically predicted lipid traits and breast cancer risk. Additional Mendelian randomization analysis approaches and sensitivity analyses were conducted to assess pleiotropy and instrument validity. Results Corresponding to approximately 15 mg/dL, one standard deviation increase in genetically predicted HDL-C was associated with a 12% increased breast cancer risk (OR: 1.12, 95% CI: 1.08–1.16). Findings were consistent after adjustment for breast cancer risk factors and were robust in several sensitivity analyses. Associations with genetically predicted triglycerides and total cholesterol were inconsistent, and no association for genetically predicted LDL-C was observed. Conclusions This study provides strong evidence that circulating HDL-C may be associated with an increased risk of breast cancer, whereas LDL-C may not be related to breast cancer risk.


Author(s):  
Kun Zhang ◽  
Shan-Shan Dong ◽  
Yan Guo ◽  
Shi-Hao Tang ◽  
Hao Wu ◽  
...  

Objective: Coronavirus disease 2019 (COVID-19) is a global pandemic caused by the severe acute respiratory syndrome coronavirus 2. It has been reported that dyslipidemia is correlated with COVID-19, and blood lipids levels, including total cholesterol, HDL-C (high-density lipoprotein cholesterol), and LDL-C (low-density lipoprotein cholesterol) levels, were significantly associated with disease severity. However, the causalities of blood lipids on COVID-19 are not clear. Approach and Results: We performed 2-sample Mendelian randomization (MR) analyses to explore the causal effects of blood lipids on COVID-19 susceptibility and severity. Using the outcome data from the UK Biobank (1221 cases and 4117 controls), we observed potential positive causal effects of dyslipidemia (odds ratio [OR], 1.27 [95% CI, 1.08–1.49], P =3.18×10 −3 ), total cholesterol (OR, 1.19 [95% CI, 1.07–1.32], P =8.54×10 −4 ), and ApoB (apolipoprotein B; OR, 1.18 [95% CI, 1.07–1.29], P =1.01×10 −3 ) on COVID-19 susceptibility after Bonferroni correction. In addition, the effects of total cholesterol (OR, 1.01 [95% CI, 1.00–1.02], P =2.29×10 −2 ) and ApoB (OR, 1.01 [95% CI, 1.00–1.02], P =2.22×10 −2 ) on COVID-19 susceptibility were also identified using outcome data from the host genetics initiative (14 134 cases and 1 284 876 controls). Conclusions: In conclusion, we found that higher total cholesterol and ApoB levels might increase the risk of COVID-19 infection.


1999 ◽  
Vol 175 (3) ◽  
pp. 259-262 ◽  
Author(s):  
T. Partonen ◽  
J. Haukka ◽  
J. Virtamo ◽  
P. R. Taylor ◽  
J. Lönnqvist

BackgroundIt has been suggested that low serum total cholesterol is associated with an increased risk of suicide.AimsTo study the association between serum total cholesterol, depression and suicide using versatile, prospective data.MethodA total of 29 133 men aged 50–69 years were followed up for 5–8 years. Baseline blood samples were analysed for serum total and high-density lipoprotein cholesterol concentrations. Self-reported depression was recorded, data on hospital treatments due to depressive disorders were derived from the National Hospital Discharge Register and deaths from suicide were identified from death certificates.ResultsLow serum total cholesterol was associated with low mood and subsequently a heightened risk of hospital treatment due to major depressive disorder and of death from suicide.ConclusionsOur results suggest that low serum total cholesterol appears to be associated with low mood and thus to predict its serious consequences.


2005 ◽  
Vol 33 (04) ◽  
pp. 525-533 ◽  
Author(s):  
Mehmet Tuǧrul Cabıoǧlu ◽  
Neyhan Ergene

Our purpose in this study was to investigate the effect of acupuncture therapy on body weight and on levels of the serum total cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol in obese women. Fifty-five women were studied in three groups as follows: (1) control group ( n = 12; mean age = 43.3 ± 4.3, and mean body mass index { BMI } = 32.2 ± 3.4); (2) electroacupuncture (EA) ( n = 22; mean age = 39.8 ± 5.3, and BMI = 34.8 ± 3.3); and (3) diet restriction ( n = 21; mean age = 42.7 ± 3.9, and BMI = 34.9 ± 3.3). EA was performed using the ear points, Sanjiao (Hungry) and Shen Men (Stomach), and the body points, LI 4, LI 11, St 25, St 36, St 44 and Liv 3, once daily, for 30 minutes, for 20 days, whereas patients on diet restriction had a 1425 Kcal diet program, that consisted of 1425 Kcal daily for 20 days. There was a 4.8% weight reduction in patients with EA application, whereas patients on diet restriction had a 2.5% weight reduction. There were significant decreases in total cholesterol and triglyceride levels in EA and diet groups compared with the control group ( p < 0.05 in both cases). Furthermore, there was a decrease in LDL levels in the EA group compared with the control group ( p < 0.05). No significant changes could be found in HDL levels among the three groups. Our results suggest that EA application in obese women may decrease the serum total cholesterol, triglyceride, and LDL cholesterol levels by increasing the serum beta endorphin level. This lipolytic effect of EA may also reduce the morbidity of obesity by mobilizing the energy stores that result in weight reduction.


2021 ◽  
Vol 11 ◽  
Author(s):  
Zhiyong Cui ◽  
Hui Feng ◽  
Baichuan He ◽  
Yong Xing ◽  
Zhaorui Liu ◽  
...  

BackgroundIt remains unclear whether an increased risk of type 2 diabetes (T2D) affects the risk of osteoarthritis (OA).MethodsHere, we used two-sample Mendelian randomization (MR) to obtain non-confounded estimates of the effect of T2D and glycemic traits on hip and knee OA. We identified single-nucleotide polymorphisms (SNPs) strongly associated with T2D, fasting glucose (FG), and 2-h postprandial glucose (2hGlu) from genome-wide association studies (GWAS). We used the MR inverse variance weighted (IVW), the MR–Egger method, the weighted median (WM), and the Robust Adjusted Profile Score (MR.RAPS) to reveal the associations of T2D, FG, and 2hGlu with hip and knee OA risks. Sensitivity analyses were also conducted to verify whether heterogeneity and pleiotropy can bias the MR results.ResultsWe did not find statistically significant causal effects of genetically increased T2D risk, FG, and 2hGlu on hip and knee OA (e.g., T2D and hip OA, MR–Egger OR = 1.1708, 95% CI 0.9469–1.4476, p = 0.1547). It was confirmed that horizontal pleiotropy was unlikely to bias the causality (e.g., T2D and hip OA, MR–Egger, intercept = −0.0105, p = 0.1367). No evidence of heterogeneity was found between the genetic variants (e.g., T2D and hip OA, MR–Egger Q = 30.1362, I2 &lt; 0.0001, p = 0.6104).ConclusionOur MR study did not support causal effects of a genetically increased T2D risk, FG, and 2hGlu on hip and knee OA risk.


2018 ◽  
Author(s):  
Ping Zeng ◽  
Xiang Zhou

AbstractAmyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disorder that is predicted to increase across the globe by ~70% in the following decades. Understanding the disease causal mechanism underlying ALS and identifying modifiable risks factors for ALS hold the key for the development of effective preventative and treatment strategies. Here, we investigate the causal effects of four blood lipid traits that include high density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol (TC), and triglycerides (TG) on the risk of ALS. By leveraging instrument variables from multiple large-scale genome-wide association studies in both European and East Asian populations, we carry out one of the largest and most comprehensive Mendelian randomization analyses performed to date on the causal relationship between lipids and ALS. Among the four lipids, we found that only LDL is causally associated with ALS and that higher LDL level increases the risk of ALS in both the European and East Asian populations. Specifically, the odds ratio of ALS per one standard deviation (i.e. 39.0 mg/dL) increase of LDL is estimated to be 1.14 (95% CI 1.05 - 1.24, p = 1.38E-3) in the European and population and 1.06 (95% CI 1.00 - 1.12, p = 0.044) in the East Asian population. The identified causal relationship between LDL and ALS is robust with respect to the choice of statistical methods and is validated through extensive sensitivity analyses that guard against various model assumption violations. Our study provides important evidence supporting the causal role of higher LDL on increasing the risk of ALS, paving ways for the development of preventative strategies for reducing the disease burden of ALS across multiple nations.


2020 ◽  
Author(s):  
Zhiyong Cui ◽  
Hui Feng ◽  
Baichuan He ◽  
Yong Xing ◽  
Zhaorui Liu ◽  
...  

Abstract Background: It remains unclear whether an increased risk of type 2 diabetes (T2D) affects the risk of osteoarthritis (OA). Methods: Here, we used two-sample Mendelian randomization (MR) to obtain non-confounded estimates of the effect of T2D and glycemic traits on hip and knee OA. We identified single nucleotide polymorphisms (SNPs) strongly associated with T2D, fasting glucose (FG) and 2-hour postprandial glucose (2hGlu) from genome-wide association studies (GWAS) . We used MR inverse variance weighted (IVW), the MR-Egger method, the weighted median (WM) and Robust Adjusted Profile Score (MR.RAPS) to reveal the associations of T2D, FG and 2hGlu with hip and knee OA risk. Sensitivity analyses were also conducted to verify whether heterogeneity and pleiotropy can bias the MR results.Results: We did not find statistically significant causal effects of genetically increased T2D risk, FG and 2hGlu on hip and knee OA (e.g., T2D and hip OA, MR-Egger OR=0.9536, 95% CI 0.5585 to 1.6283, p=0.8629). It was confirmed that horizontal pleiotropy was unlikely to bias the causality (e.g., T2D and hip OA, MR-Egger, intercept=-0.0032, p=0.8518). No evidence of heterogeneity was found between the genetic variants (e.g., T2D and hip OA, MR-Egger Q=40.5481, I2=0.1368, p=0.2389). Conclusions: Our MR study did not support causal effects of a genetically increased T2D risk, FG and 2hGlu on hip and knee OA risk.


Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Sheila M Manemann ◽  
Suzette J Bielinski ◽  
Ethan D Moser ◽  
Jennifer L St. Sauver ◽  
Paul Y Takahashi ◽  
...  

Background: Larger within-patient variability of lipid levels has been associated with an increased risk of cardiovascular disease (CVD). However, measures of lipid variability are not currently used clinically. We investigated the feasibility of calculating lipid variability within a large electronic health record (EHR)-based population cohort and assessed associations with incident CVD. Methods: We identified all individuals ≥40 years of age who resided in Olmsted County, MN on 1/1/2006 (index date) without prior CVD. CVD was defined as myocardial infarction, coronary artery bypass graft surgery, percutaneous coronary intervention or stroke. Patients with ≥3 measurements of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and/or triglycerides during the 5 years before the index date were retained in the analyses. Lipid variability was calculated using variability independent of the mean (VIM). Patients were followed through 9/30/2017 for incident CVD (including CVD death). Cox regression was used to investigate the association between quintiles of lipid VIMs and incident CVD. Results: We identified 18,642 individuals (mean age 60; 55% female) who were free of CVD at baseline and VIM calculated for at least one lipid measurement. After adjustment, those in the highest VIM quintiles of total cholesterol had a 25% increased risk of CVD (Q5 vs. Q1 HR: 1.25, 95% CI: 1.08-1.45; Table). We observed similar results for LDL-C (Q5 vs. Q1 HR: 1.20, 95% CI: 1.04-1.39) and HDL-C (Q5 vs. Q1 HR: 1.25, 95% CI: 1.09-1.43). There was no association between triglyceride variability quintiles and CVD risk. Conclusion: In a large EHR-based population cohort, high variability in total cholesterol, HDL-C and LDL-C was associated with an increased risk of CVD, independently of traditional risk factors, suggesting it may be a target for intervention. Lipid variability can be calculated in the EHR environment but more research is needed to determine its clinical utility.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Paul Carter ◽  
Mathew Vithayathil ◽  
Siddhartha Kar ◽  
Rahul Potluri ◽  
Amy M Mason ◽  
...  

Laboratory studies have suggested oncogenic roles of lipids, as well as anticarcinogenic effects of statins. Here we assess the potential effect of statin therapy on cancer risk using evidence from human genetics. We obtained associations of lipid-related genetic variants with the risk of overall and 22 site-specific cancers for 367,703 individuals in the UK Biobank. In total, 75,037 individuals had a cancer event. Variants in the HMGCR gene region, which represent proxies for statin treatment, were associated with overall cancer risk (odds ratio [OR] per one standard deviation decrease in low-density lipoprotein [LDL] cholesterol 0.76, 95% confidence interval [CI] 0.65–0.88, p=0.0003) but variants in gene regions representing alternative lipid-lowering treatment targets (PCSK9, LDLR, NPC1L1, APOC3, LPL) were not. Genetically predicted LDL-cholesterol was not associated with overall cancer risk (OR per standard deviation increase 1.01, 95% CI 0.98–1.05, p=0.50). Our results predict that statins reduce cancer risk but other lipid-lowering treatments do not. This suggests that statins reduce cancer risk through a cholesterol independent pathway.


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