Associations of genetically predicted fatty acid levels across the phenome: A mendelian randomisation study

Causal relationship and mediating role between depression and cognitive performance

BACKGROUND

Recent studies have increasingly emphasized the robust correlation between depression and cognitive function. However, it remains unclear whether this relationship is causal or merely coincidental. To address this uncertainty, we conducted two-sample bidirectional Mendelian randomization (MR) analyses to investigate the connection between depression and cognitive performance.

METHODS

We sourced genome-wide association study (GWAS) data for depression (NSNPs=21,306,230) from the FinnGen (R10) and for cognitive performance (NSNPs=10,049,954) from the IEU GWAS database. Causal effects employed methodologies such as Inverse variance weighted (IVW), weighted median, MR Egger, simple mode and weighted mode. Two-step analysis determined the contribution of the mediator variable to the outcomes. To determine stability and reliability, sensitivity analyses were performed that included an assessment of heterogeneity, horizontal pleiotropy, and the leave-one-out techniques.

RESULTS

This MR analysis identified 8 independent significant SNPs associated with depression and 81 SNPs linked to cognitive performance. Our findings revealed that depression increases the risk of developing deteriorating cognitive performance (IVW β, -0.11; 95 % confidence interval (CI), -0.18 - -0.05; PIVW value= 5.97E-04). Conversely, cognitive performance decline could also predispose individuals to depression [odds ratio (OR)IVW, 0.85; 95 % CI, 0.76 - 0.95; PIVW value=0.004]. Multivariate MR analysis confirmed the robustness of this bidirectional association. A two-step MR mediation analysis indicated that the pathway from depression to cognitive performance is mediated by pain, with a mediation effect size of -0.022 and a mediation ratio of 28.95 %. The pathway from cognitive performance to depression is mediated by frailty, with a mediation effect value of -0.028, representing 22.40 % of the mediation proportion.

CONCLUSION

A two-way causal relationship between depression and cognitive performance, with pain and frailty being mediating factors, respectively. Future research should prioritize mechanistic studies, targeted interventions, and personalized approaches to disentangle and mitigate the bidirectional effects of depression and cognitive performance.

Circulating polyunsaturated fatty acids percentages and coronary artery disease incidence and mortality: Observational and Mendelian randomization analyses

BACKGROUND

The roles of polyunsaturated fatty acids (PUFAs) in preventing coronary artery disease (CAD) remain controversial. This study aimed to investigate the relationships between circulating PUFA percentages and CAD outcomes using observational and Mendelian randomization (MR) approaches.

METHODS

We analyzed data from 203,373 UK Biobank participants without CAD at baseline. Four PUFA percentages (docosahexaenoic acid [DHA]%, omega-3%, linoleic acid [LA]%, and omega-6%) were examined in relation to incident CAD and CAD mortality. MR analyses included one-sample linear and nonlinear approaches, as well as two-sample univariable and multivariable methods. Observational and one-sample MR analyses were conducted overall and stratified by age and sex.

RESULTS

During a median follow-up of 13.2 years, 16,098 incident CAD cases and 1243 CAD deaths occurred. Observationally, all PUFA percentages were inversely associated with both CAD outcomes. In one-sample MR, genetically predicted DHA% was strongly associated with decreased risk of CAD mortality (hazard ratio [HR] 0.31, 95 % confidence interval [CI] 0.15-0.62, P = 9.71 × 10-4), with a pronounced effect in individuals aged ≥58 years (HR 0.20, 95 % CI 0.09-0.43, P = 4.75 × 10-5). Genetically predicted omega-6% was associated with a decreased risk of incident CAD (HR 0.84, 95 % CI 0.76-0.92, P = 1.26 × 10-4), with a significant effect in females but not in males. Two-sample MR confirmed these findings, suggesting partial mediation through lipid pathways. Nonlinear MR analyses validated these linear associations without threshold effects.

CONCLUSIONS

Observational and genetically predicted high DHA% protects against CAD mortality, particularly in older adults. Omega-6% and incident CAD exhibited sex-specific inverse associations. These findings underscore the importance of considering age and sex in PUFA-based strategies for CAD prevention.

The role of preeclampsia in breast cancer risk: insights from Mendelian randomization study

BACKGROUND

The relationship between preeclampsia and breast cancer risk is still debated, with observational studies yielding inconsistent results. This research aims to clarify the causal link between preeclampsia and breast cancer using Mendelian randomization (MR) methods.

METHODS

We utilized genome-wide association study (GWAS) data to identify single nucleotide polymorphisms (SNPs) that are significantly associated with preeclampsia, which served as genetic instruments. A two-sample Mendelian randomization (TSMR) approach was applied, primarily using inverse variance weighting (IVW) to assess the causal impact of preeclampsia on breast cancer risk. To strengthen our findings, a meta-analysis of IVW estimates from both discovery and validation cohorts was performed, complemented by sensitivity analyses to investigate heterogeneity and potential horizontal pleiotropy.

RESULTS

In the discovery cohort, IVW analysis revealed a potential inverse relationship between preeclampsia and breast cancer risk (OR, 0.971; 95% CI, 0.947-0.996; P = 0.022). However, the validation cohort did not demonstrate a significant causal association (OR, 0.992; 95% CI, 0.975-1.008; P = 0.327). The combined meta-analysis indicated that preeclampsia might be linked to a lower risk of breast cancer (OR, 0.986; 95% CI, 0.972-0.999; P = 0.041). In subgroup analysis, preeclampsia was found to have a potential association only with estrogen receptor (ER)-negative breast cancer (OR, 0.956; 95% CI, 0.916-0.999; P = 0.043), while no significant link was observed with estrogen receptor (ER)-positive breast cancer (OR, 0.972; 95% CI, 0.945-1.000; P = 0.051). Sensitivity analyses indicated no significant heterogeneity or evidence of horizontal pleiotropy (P > 0.05).

CONCLUSION

This MR study, supported by a robust meta-analysis, suggests that preeclampsia may have a protective effect against breast cancer, especially ER-negative breast cancer. However, to firmly establish this relationship, additional prospective studies with larger populations are warranted. Moreover, further exploration of the biological mechanisms underlying this potential association is needed through both in vitro and in vivo research.

Development of a non-targeted metabolomics-based screening method for elucidating the metabolic characteristics and potential applications of Lacticaseibacillus paracasei

The increasing demand for healthy foods has led to widespread interest in lactic acid bacteria due to their potential health benefits. We propose the hypothesis that Lacticaseibacillus paracasei (L. paracasei) can produce beneficial metabolites under specific conditions, which offers potential applications in functional foods. In this study, we analyzed the fermentation supernatants and brown fermented milk metabolites of L. paracasei to identify those with possible applications in functional foods, which have great potential. We found that L. paracasei IMAU32642 produced unique metabolites, including docosahexaenoic acid (DHA), leucyl phenylalanine, and oleic acid in its fermentation supernatant. Meanwhile, L. paracasei IMAU60048 exhibited unique application prospects in brown fermented milk, with higher yields of arachidonic acid and caprylic acid compared to other strains. This study offers a new and effective method for screening L. paracasei. The study can promote the development of functional foods and enhance their health value.

Relationship of urate-lowering drugs with cognition and dementia: A Mendelian randomization and observational study

Prior studies have presented paradoxical results regarding the association of uric acid-lowering drugs (ULDs) therapy with cognition and dementia. We aimed to explore this correlation. In this observational study, we extracted and analyzed the data from the National Health and Nutrition Examination Survey (NHANES) database and the FDA Adverse Event Reporting System (FAERS) database to investigate the association of ULDs with cognitive function and dementia. Two-simple Mendelian randomization (MR) and multivariable MR (MVMR) analyses were conducted to evaluate the causal associations of ULDs for all common types of dementia, including Alzheimer's disease (AD), vascular dementia (VD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB). In the NHANES database, regardless of whether ULDs were included only or adjusted for covariates, the linear regression models did not find a correlation between ULDs and three cognitive tests (all p > 0.05). In the FAERS database, the dementia signal in ULDs lost significance after stepwise constraints (the lower limit of proportional reporting ratio lower than 1). In the two-sample MR analysis, allopurinol was associated with an increased risk of VD (OR = 123.747, p = 0.002), and a positive causal relationship was found between uricosuric drugs and AD (OR = 1.003, p = 0.003). However, the significance disappeared after adjusting for risk factors of dementia (p > 0.05). This study indicates that ULDs may not be related to an increase or decrease risk of cognition function and dementia, including all common types of dementia (AD, VD, FTD, and DLB).

Metabolomics profiling of Type D personality traits

OBJECTIVE

Type D (Distressed) personality combines negative affectivity (NA) and social inhibition (SI) and is associated with an increased risk of cardiometabolic diseases. Here, we examined the association of Type D traits with 230 (predominantly) lipid metabolites and metabolite ratios.

METHODS

Four Dutch cohorts were included, comprising 10,834 individuals. Type D personality traits were measured by self-report questionnaires. A proton nuclear magnetic resonance (NMR) metabolomics platform provided 149 absolute measures (98 belonging to lipoprotein subclasses) and 81 derived ratios. For all, linear regression analyses were performed within each cohort, followed by random-effects meta-analyses. A per-measure FDR q-value<0.05 was set as a study-wise significant association.

RESULTS

SI was significantly associated with a lower omega-3 fatty acids to total fatty acids (FAw3.FA%) ratio, and a lower free cholesterol to total lipids ratio in very small VLDL (XS.VLDL.FC%). FAw3.FA% was also associated to NA (no study-wise significance though). NA showed a suggestive replication (p-value<.05) of the previous reported associations with depression for 5 out of 18 metabolites from the same metabolomics platform: triglycerides in HDL, serum total triglycerides, VLDL cholesterol, mean diameter for VLDL particles and VLDL triglycerides.

CONCLUSIONS

In this large meta-analysis, SI was associated with omega-3 fatty acids to total fatty acids ratio, which is suggestive of lower omega-3 fatty acid intake. Only some metabolite biomarkers showed tentative links to Type D and NA. In sum, it seems that there are no major alterations in lipid metabolism associated with Type D traits.

Effect of erythropoiesis-stimulating agents on malignant neoplasms: FAERS database and Mendelian randomization

BACKGROUND

The relationship between erythropoiesis-stimulating agents (ESAs) and malignant neoplasms (MNs) has been controversial in previous studies. Our study aimed to explore the correlation between ESAs and MNs.

RESEARCH DESIGN AND METHODS

Drug-target Mendelian randomization (MR) analyses were conducted to evaluate the causal associations of ESAs for 12 classifications of MNs. Meanwhile, a pharmacovigilance study was performed by extracting adverse events (AEs) from the FDA Adverse Event Reporting System (FAERS) database to validate and complement our findings. MR analysis revealed negative association of ESAs with MN of ovary (p = 0.047), liposarcoma (p = 0.001), small cell lung cancer (p = 0.017), colorectal cancer (p = 0.004), and brain meningioma (p = 0.004) and revealed positive association of ESAs with MN of bladder (p = 0.001), eye and adnexa (p = 0.012), heart, mediastinum, and pleura (p = 0.032), lip (p = 0.041), larynx (p = 0.015), non-small cell lung cancer (p = 0.009), and malignant melanoma (p = 0.001). Positive signals were found in MN of hematological system, digestive organs, central nervous system, eye and adnexa, head and neck cancer, lung cancer, and mucinous and mucinous cystic tumor in FAERS database (all reporting odds ratio and proportional reporting ratio >1).

CONCLUSION

ESAs were causally correlated with many types of MNs. The use of ESAs in these tumors needs more attention.

Investigation of the causal relationship between breast cancer and thyroid cancer: a set of two-sample bidirectional Mendelian randomization study

PURPOSE

A potential association between breast (BC) and thyroid cancer (TC) has been observed. We investigated if the relationship between BC and TC is causal using bidirectional Mendelian randomization (MR) in Asian and European populations.

METHODS

BC-linked single nucleotide polymorphisms (SNPs) were acquired from a genome-wide association study (GWAS) conducted by the Breast Cancer Association Consortium and Biobank Japan. The most recent TC GWAS data were obtained from the FinnGen Project and National Biobank of Korea. We assessed the potential causal relationship between BC and TC using various MR methods, including inverse-variance-weighting (IVW). Sensitivity, heterogeneity, and pleiotropic tests were performed to assess reliability.

RESULTS

We found a bidirectional causal association between BC and TC within Europeans (IVW, TC on BC: odds ratio [OR] 1.090, 95% confidence interval [CI]: 1.012-1.173, P = 0.023; BC on TC: OR 1.265, 95% CI: 1.158-1.381, P < 0.001). A one-way causal relationship between BC susceptibility and TC risk was found in Asians (IVW BC on TC: OR 2.274, 95% CI: 2.089-2.475, P < 0.001). Subsequently, we identified a noteworthy bidirectional causal relationship between estrogen receptor (ER)-positive BC and TC (IVW, TC on ER-positive BC: OR 1.104, 95% CI: 1.001-1.212, P = 0.038; ER-positive BC on TC: OR 1.223, 95%CI: 1.072-1.395, P = 0.003), but not ER-negative BC and TC in Europeans.

CONCLUSION

We revealed a reciprocal causal association between ER-positive BC and TC. These findings establish a theoretical framework for the simultaneous surveillance and treatment of BC and TC.

Causal effects between gut microbiota and endometriosis: a two-sample Mendelian randomisation study

BACKGROUND

Previous observational evidence has indicated the potential involvement of the gut microbiota (GM) in the development of endometriosis. However, the causal relationship of the association remains to be investigated.

METHOD

Genome-wide association study (GWAS) data of GM was obtained from the MiBioGen consortium, and GWAS for endometriosis data was from the FinnGen consortium. Initially, a two-sample Mendelian randomisation (MR) analysis was performed to identify specific bacteria associated with endometriosis. Inverse variance-weighted (IVW) was used as the main MR analysis to infer causal relationships. The other four popular MR methods including MR-Egger regression, weighted mode, weighted median, and simple mode were used for secondary confirmation. Subsequently, these selected bacteria were employed as exposure to investigate their causal effects on six sub-types of endometriosis. Furthermore, reverse MR analysis was implemented to evaluate the reverse causal effects. Cochran's Q statistics was used to test the heterogeneity of instrumental variables (IVs); MR-Egger regression was used to test horizontal pleiotropy; MR-PRESSO and leave-one-out sensitivity analysis were applied to find significant outliers.

RESULT

A total of 1131 single nucleotide polymorphisms (SNPs) were collected as IVs for 196 GM taxa with endometriosis as the outcome. We identified 12 causal relationships between endometriosis and GM taxa including 1 phylum, 3 families, 2 orders, and 6 genera (Rikenellaceae RC9 gut group, Eubacterium ruminantium group, Faecalibacterium, Peptococcus, Clostridium sensu stricto 1, and Ruminococcaceae UCG005). Utilizing the Bonferroni method, we identified phylum Cyanobacteria as the strongest associated GM taxa. Subsequently, 6 significant causal effects were uncovered between the 12 selected specific GM and 6 sub-types of endometriosis. Meanwhile, no reverse causal relationship was found. Further, no horizontal pleiotropy and no significant outliers were detected in the sensitive analysis.

CONCLUSIONS

This MR analysis revealed significant causal effects between GM and endometriosis and phylum Cyanobacteria had the strongest association.

The association between inflammatory cytokines and sarcopenia-related traits: a bi-directional Mendelian randomization study

BACKGROUND

Sarcopenia is among the most common musculoskeletal illnesses, yet its underlying biochemical mechanisms remain incompletely understood. Identifying the relationship of inflammatory cytokines with sarcopenia components would help understand the etiology of sarcopenia. We performed a bi-directional Mendelian randomization study to explore the causal relationship between 41 inflammatory cytokines and sarcopenia-related traits.

METHODS

The study was performed in two stages using bidirectional dual-sample Mendelian randomization. We obtained aggregated statistical data on inflammatory factors, low grip strength, and ALM from genome-wide association studies. To explore the causal association between exposure and outcomes, we primarily utilized the inverse variance weighted strategy. Furthermore, we conducted sensitivity analyses through the use of Mendelian randomization (MR) Egger, weighted median and simple mode methods. To evaluate robustness of the results and to identify and adjust for horizontal pleiotropy, we performed the MR Pleiotropy RESidual Sum and Outlier test, the MR Egger intercept test, and a leave-one-out analysis.

RESULTS

The results displayed a potential association between interleukin-10 (OR: 1.046, 95% CI: 1.002-1.093, p = 0.042) and vascular endothelial growth factor (OR: 1.024, 95% CI: 1.001-1.047, p = 0.038) and the risk of low hand-grip strength. Moreover, interferon gamma-induced protein 10 (OR: 1.010, 95% CI: 1.000-1.019, p = 0.042) and macrophage colony-stimulating factor (OR: 1.010, 95% CI: 1.003-1.017, p = 0.003) were significantly linked to a higher risk of ALM.

CONCLUSION

We identified a causal relationship between multiple inflammatory factors and sarcopenia-related traits. Our study offers valuable insights into innovative methods for the sarcopenia prevention and treatment by regulating inflammatory factors.

Causal linkage of Graves' disease with aging: Mendelian randomization analysis of telomere length and age-related phenotypes

BACKGROUND

Aging is an irreversible progressive decline in physical function. Graves' disease (GD) is a common cause of hyperthyroidism and is characterized by elevated levels of the thyroid hormone (TH). High TH levels are associated with aging and a shortened lifespan. The causal relationship between GD and aging has yet to be investigated.

METHODS

We used genome-wide association study (GWAS) datasets and Mendelian randomization (MR) analysis to explore the causal link between GD and aging. To assess the statistical power of instrumental variables (IVs), F-statistics and R2 were used. MR analysis was conducted using inverse-variance weighting (IVW), MR-Egger, weighted median, and weighted mode. The odds ratio (OR) and 95% CI were calculated to estimate the relative risk of GD to the outcomes. The Cochran Q test, I2, MR-PRESSO test, and MR-Egger regression intercept were calculated using statistical and leave-one-out analyses to test the heterogeneity, horizontal pleiotropy, and stability of the IVs on the outcomes.

RESULTS

F-statistics of the five IVs were greater than 10, and the R2 values ranged from 0.033 to 0.156 (R2 > 0.01). According to the results of the IVW analysis, GD had no causal effect on facial aging (p = 0.189), age-related macular degeneration (p = 0.346), and Alzheimer's disease (p = 0.479). There was a causal effect of GD on the remaining outcomes: telomere length (TL) (OR = 0.982; 95%CI:0.969-0.994; p = 0.004), senile cataract (OR = 1.031; 95%CI:1.002-1.060; p = 0.033), age-related hearing impairment (OR = 1.009; 95%CI:1.004-1.014; p = 0.001), chronic obstructive pulmonary disease (COPD) (OR = 1.055; 95%CI:1.008-1.103; p = 0.020), and sarcopenia (OR = 1.027; 95%CI:1.009-1.046; p = 0.004).

CONCLUSIONS

GD accelerates the occurrence of age-related phenotypes including TL, senile cataracts, age-related hearing impairment, COPD, and sarcopenia. In contrast, there are no causal linkages between GD and facial aging, age-related macular degeneration, or Alzheimer's disease. Further experimental studies could be conducted to elucidate the mechanisms by which GD facilitates aging, which could help slow down the progress of aging.

PUFA and intrahepatic cholestasis of pregnancy: a two-sample Mendelian randomisation analysis

This study aimed to explore the potential causal association between PUFA and the risk of intrahepatic cholestasis of pregnancy (ICP) using Mendelian randomisation (MR) analysis. A two-sample MR analysis was conducted utilising large-scale European-based genome-wide association studies summary databases. The primary MR analysis was carried out using the inverse variance-weighted (IVW) method, complemented by other methods such as MR-egger, weighted-median and weighted mode. Sensitivity analysis was also performed to validate the robustness of the findings. Results indicated a 31 % reduced risk of ICP for every 1 standard deviation (sd) increase in n-3 fatty acids levels (OR = 0·69, 95 % CI: 0·54, 0·89, P = 0·004) and in the ratio of n-3 fatty acids to total fatty acids (OR = 0·69, 95 % CI: 0·53, 0·91, P = 0·008). Conversely, there was a 51 % increased risk of ICP for every 1 sd increase in the ratio of n-6 fatty acids to n-3 fatty acids (OR = 1·51, 95 % CI: 1·20, 1·91, P < 0·001) and a 138 % increased risk for every 1 sd increase in the ratio of linoleic fatty acids to total fatty acids (OR = 2·38, 95 % CI: 1·55, 3·66, P < 0·001). The findings suggest that n-3 fatty acids may have a protective effect against the risk of ICP, while n-6 fatty acids and linoleic fatty acids could be potential risk factors for ICP. The supplementation of n-3 fatty acids, as opposed to n-6 fatty acids, could be a promising strategy for the prevention and management of ICP.

Causality between major depressive disorder and functional dyspepsia: a two-sample Mendelian randomization study

Background

To investigate the causal relationship between major depression and functional dyspepsia using two-sample Mendelian randomization.

Methods

Data for major depression and functional dyspepsia were obtained from genome-wide association studies. We selected Single Nucleotide Polymorphisms (SNPs) strongly associated with severe depression. Mendelian randomization analysis was conducted using methods such as Inverse-Variance Weighted (IVW), MR-Egger, and Weighted Median Estimator (WME). Sensitivity analysis was performed to assess the robustness of the results.

Results

A total of 31 eligible SNPs were identified as instrumental variables for major depression. IVW analysis indicated a positive causal relationship between the two conditions (β = 0.328; SE = 0.137; p = 0.017), suggesting that severe depression increases the risk of functional dyspepsia (OR = 1.389; 95% CI: 1.062-1.816). Sensitivity tests showed no evidence of heterogeneity or horizontal pleiotropy (p > 0.05).

Conclusion

MR analysis had shown that major depressive disorder is associated with an increased risk of functional dyspepsia.

The Causal Relationship between PCSK9 Inhibitors and Osteoporosis Based on Drug-Targeted Mendelian Combined Mediation Analysis

PCSK9 inhibitors have been shown to lower serum low density lipoprotein cholesterol (LDL-C) levels and are considered integral in the treatment of cardiovascular diseases. However, the potential association between PCSK9 inhibitors and osteoporosis is unclear now. In this study, drug-targeted mendelian randomization (MR) was utilized in conjunction with mediation analysis including bone mineral density (BMD), total 25-hydroxyvitamin D (T25(OH)D) levels and calcium supplementation to investigate the causal relationship between PCSK9 inhibitors and osteoporosis. The LDL-C level was chosen as the exposure variable in a sample size of 173,082 individuals. We conducted a MR analysis on the relationship between PCSK9 inhibitors and osteoporosis, elucidating the mediators involved. Utilizing the inverse variance weighted (IVW) method, we found the risk of osteoporosis was reduced by 0.6% in those who used PCSK9 inhibitors compared with non-users (OR: 0.994, 95%CI: 0.991-0.998, P < 0.001). In people aged 30-45 years, the risk of low BMD was 1.176 times higher among PCSK9 inhibitor users compared to non-users (OR: 1.176, 95%CI: 1.017-1.336, P = 0.045). Conversely, people aged 45-60 years who used PCSK9 inhibitors had a 14.9% lower risk of low BMD compared to non-users (OR: 0.851, 95%CI: 0.732-0.968, P = 0.007). Mediation analysis revealed that 43.33% of the impact of PCSK9 inhibitors on osteoporosis was mediated through BMD levels, with the remaining 56.67% being a direct effect. Effects of PCSK9 inhibitors on BMD levels varied in different ages. In addition, the risk of high serum T25(OH)D levels were 1.091 times among PCSK9 inhibitor users compared to non-users (OR: 1.091, 95%CI: 1.065-1.112, P < 0.001), providing valuable insights for clinicians.

Association between smoking and alcohol drinking and benign adrenal tumors: a Mendelian randomization study

BACKGROUND

In recent years, the detection rate of adrenal tumors has increased, but it is unclear whether smoking and alcohol drinking are risk factors for benign adrenal tumors. The objective of this study is to employ Mendelian randomization (MR) analysis to explore the causal relationship between smoking, alcohol drinking and susceptibility to benign adrenal tumors.

METHODS

We acquired large-scale data from publicly accessible databases on genome-wide association studies (GWAS) pertaining to smoking, alcohol drinking and benign adrenal tumors. A total of 11 sets of instrumental variables (IVs) and 281 associated single nucleotide polymorphic (SNP) loci were identified. The Mendelian randomization analyses were conducted using inverse variance weighting (IVW), MR-Egger regression and weighted median estimation (WME) methods, in addition to sensitivity analyses.

RESULTS

There is no causal relationship between smoking status, alcohol drinking status, alcohol intake frequency, alcohol taken with meals, alcohol consumption and benign adrenal tumors, while pack years of smoking and cigarettes per day are risk factors for benign adrenal tumors. The IVW analysis revealed that both the pack years of smoking and cigarettes per day were positively associated with an increased risk of benign adrenal tumors (OR = 2.853, 95%CI = 1.384-5.878, p = 0.004; OR = 1.543, 95%CI = 1.147-2.076, p = 0.004). Two SNPs (rs8042849 in the analysis of pack years of smoking and rs8034191 in the analysis of cigarettes per day) significantly drove the observed causal effects.

CONCLUSION

Two-sample Mendelian randomization analysis showed a causal effect between smoking but not alcohol consumption and benign adrenal tumors.

Exploring the Relationship Between Atorvastatin and Memory Loss: A Comprehensive Analysis Integrating Real-World Pharmacovigilance and Mendelian Randomization

BACKGROUND AND OBJECTIVE

Atorvastatin is a drug widely used to prevent cardiovascular and cerebrovascular diseases. Current observational studies suggest that atorvastatin may be associated with cognitive dysfunction (especially memory loss). However, some studies have suggested that dyslipidemia may be an important factor in cognitive dysfunction. The purpose of this study was to perform a pharmacovigilance analysis using real-world data from the US Food and Drug Administration's Adverse Event Reporting System (FAERS) to assess whether memory loss is an adverse effect of atorvastatin and to further clarify its causality through Mendelian randomization (MR).

METHODS

We extracted real-world data from the FAERS database (Quarter 1 2004 to Quarter 1 2023). Disproportionality analysis methods and measures of association such as the reporting odds ratio (OR), proportional reporting ratio, Bayesian confidence interval progressive neural network, and polynomial Gamma Poisson distribution reduction were used to assess whether memory loss was an adverse effect of atorvastatin. In addition, we used MR to evaluate causality in depth.

RESULTS

In the pharmacovigilance analysis of atorvastatin, we extracted four datasets of clinical symptoms associated with memory loss from the FAERS database [Amnesia (n = 1196), Memory impairment (n = 840), Transient global amnesia (n = 38), and Retrograde amnesia (n = 9)]. The reporting OR, proportional reporting ratio, Bayesian confidence interval progressive neural network, and Gamma Poisson distribution reduction all showed positive results for amnesia, transient global amnesia, and retrograde amnesia, while the reporting OR and Bayesian confidence interval progressive neural network also showed positive results for memory disorders. Thus, memory loss was a frequent side effect of atorvastatin. The MR analyses were used to further evaluate the association between statins and memory loss. The results of the MR analysis (statins and memory loss) are as follows: Ivw (mre) (β = 0.11 [OR = 1.11], P = 0.01 < 0.05) and the OR and β directions of MR-Egger and weighted mode were the same. The results of the MR analysis (statins and mitochondrial DNA copy number) are as follows: Ivw(mre) (β = -0.03 [OR = 0.96], P < 0.01) and the OR and β direction of MR-Egger and weighted mode are the same. The results of the MR analysis (DNA copy number and memory loss) are as follows: Ivw(β = - 0.06 [OR = 0.94], P = 0.04 < 0.05) and the OR and β direction of MR-Egger and weighted mode were the same. The pleiotropy test did not find horizontal diversity in our results.

CONCLUSIONS

This study suggests that memory loss is a notable adverse event associated with atorvastatin and provides evidence indicating a potential causal relationship between atorvastatin and memory loss. We also found that statins may further affect memory by affecting mitochondrial function. Therefore, in the clinical use of atorvastatin, it is important to carefully monitor the changes in cognitive function of patients. Second, a pharmacovigilance analysis combined with MR was used in this study to provide a new approach for the study of adverse drug reactions. This comprehensive analysis method helps to evaluate the safety of drugs and the risk of adverse reactions more comprehensively and provides doctors with a more accurate clinical decision-making basis.

Association between atorvastatin and erectile dysfunction: a comprehensive analysis incorporating real-world pharmacovigilance and Mendelian randomization

Background

Atorvastatin is a commonly prescribed medication for the prevention of cardiovascular diseases. Recent observational studies have suggested a potential association between atorvastatin use and the occurrence of Erectile Dysfunction (ED). In this study, we aimed to explore the relationship between atorvastatin and ED using real-world data from the FAERS database and employed Mendelian randomization to assess causality.

Methods

To evaluate the disproportionality of atorvastatin in relation to ED, we conducted several pharmacovigilance analyses, including odds ratio (ROR), proportional reporting ratio (PRR), Bayesian Confidence propagation neural network (BCPNN), and gamma-Poisson contractile apparatus (GPS). Additionally, we employed Mendelian randomization to investigate the causal relationship between atorvastatin and ED.

Results

Pharmacovigilance disproportionality analysis revealed a significant association between atorvastatin and ED, as indicated by the following results: ROR [3.707078559, 95% CI (3.33250349, 4.123756054)], PRR [3.702969038, χ2 (669.2853829)], IC [1.870490139, IC025 (1.702813857)], and EBGM [3.656567867, EBGM05 (3.28709656)]. Furthermore, the two-sample Mendelian randomization analysis provided evidence supporting a causal relationship between atorvastatin use and ED, with an inverse variance weighted estimate of β = 3.17 (OR = 23.91, p = 0.02 < 0.05).

Conclusion

Based on comprehensive analyses incorporating pharmacovigilance and Mendelian randomization, our findings suggest that atorvastatin use is associated with an increased risk of ED and indicate a causal relationship. These results emphasize the importance of considering potential adverse effects, such as ED, when prescribing atorvastatin for cardiovascular disease prevention. Further research and clinical monitoring are warranted to better understand the underlying mechanisms and develop appropriate strategies to mitigate this side effect.

Association of thrombopoietin-related drugs with thromboembolic events: Mendelian randomization and a real-world study

Background

Studies have shown conflicting results when using thrombopoietin-related drugs (TPORD) for thromboembolic events (TEEs). Our study aimed to explore the correlation between TPORDs and TEEs.

Method

Drug-targeted Mendelian randomization (MR) and multivariate MR (MVMR) analysis were used to explore the causal relationship between TPORDs and TEEs such as venous thromboembolism (VTE), deep vein thrombosis (DVT), pulmonary embolism (PE), myocardial infarction (MI) and ischemic stroke (STR). At the same time, a real-world study was conducted by extracting adverse events (AEs) from the FDA Adverse Event Reporting System database included in AERSMine to further validate our findings.

Outcome

In drug-target MR, TPORDs were associated with VTE (OR = 1.193, 95% confidence interval (CI): 1.001-1.423, p = 0.049], DVT (OR = 1.321, 95% CI: 1.027-1.700, p = 0.030), MI (OR = 1.216, 95% CI: 1.010-1.464, p = 0.039), STR (OR = 1.224, 95% CI: 1.021-1.468, p = 0.029). VTE/DVT/STR remained stable in MVMR (VTE: OR = 1.3, 95% CI: 1.187-1.422, p < 0.001; DVT: OR = 1.465,95% CI:1.285-1.671, p < 0.001; STR: OR = 1.119, 95% CI: 1.018-1.229, p = 0.019) and real-world studies [lower bound of proportional reporting ratio (ROR) greater than 1]. The significance of myocardial infarction disappeared in MVMR (OR = 0.996, 95% CI: 0.894-1.109, p = 0.942) and in real-world studies (lower ROR lower than 1). There was no evidence of a causal relationship between TPORD and PE (OR = 1.244, 95% CI: 0.969-1.597, p = 0.087), but it generated a signal from a real-world study (lower bound of ROR greater than 1).

Conclusion

This study suggests that TPORDs may be associated with an increased risk of TEEs, particularly AEs leading to VTE/DVT/STR. In addition, the relationship between TPORDs and PE/MI is debatable and requires more research.

Integrative polygenic analysis of the protective effects of fatty acid metabolism on disease as modified by obesity

Dysregulation of fatty acid metabolites can play a crucial role in the progression of complex diseases, such as cardiovascular disease, digestive diseases, and metabolic diseases. Metabolites can have either protective or risk effects on a disease; however, the details of such associations remain contentious. In this study, we demonstrate an integrative PheWAS approach to establish high confidence, causally suggestive of metabolite-disease associations for three fatty acid metabolites, namely, omega-3 fatty acids, omega-6 fatty acids, and docosahexaenoic acid, for 1,254 disease endpoints. Metabolite-disease associations were established if there was a concordant direction of effect and significance for metabolite level and genetic risk score for the metabolite. There was enrichment for metabolite associations with diseases of the respiratory system for omega-3 fatty acids, diseases of the circulatory system and endocrine system for omega-6 fatty acids, and diseases of the digestive system for docosahexaenoic acid. Upon performing Mendelian randomization on a subset of the outcomes, we identified 3, 6, and 15 significant diseases associated with omega-3 fatty acids, omega-6 fatty acids, and docosahexaenoic acid, respectively. We then demonstrate a class of prevalence-risk relationships indicative of (de)canalization of disease under high and low fatty acid metabolite levels. Finally, we show that the interaction between the metabolites and obesity demonstrates that the degree of protection afforded by fatty acid metabolites is strongly modulated by underlying metabolic health. This study evaluated the disease architectures of three polyunsaturated fatty acids (PUFAs), which were validated by several PheWAS modes of support. Our results not only highlight specific diseases associated with each metabolite but also disease group enrichments. In addition, we demonstrate an integrative PheWAS methodology that can be applied to other components of the human metabolome or other traits of interest. The results of this study can be used as an atlas to cross-compare genetic with non-genetic disease associations for the three PUFAs investigated. The findings can be explored through our R shiny app at https://pufa.biosci.gatech.edu.

The Causal Relationship Between Gastroesophageal Reflux Disease and Chronic Obstructive Pulmonary Disease: A Bidirectional Two-Sample Mendelian Randomization Study

Background

Gastroesophageal reflux disease (GERD) and Chronic Obstructive Pulmonary Disease (COPD) often coexist and have been associated in observational studies. However, the real potential causal relationship between GERD and COPD is unknown and not well established.

Methods

In this study, we conducted a bidirectional two-sample Mendelian randomization(MR) to estimate whether GERD and COPD are causal. The GERD genetic data is from summary level data of a genome-wide association (GWAS) meta-analysis (Ncases = 71,522, Ncontrol=26,079). The COPD GWAS are available from the FinnGen (Ncases=16,410, Ncontrol=283,589). MR-Egger regression, Weighted Median, and Inverse-variance weighted (IVW) were used for MR analysis from the R package "TwoSampleMR", and IVW was the dominant estimation method. Additionally, the MR pleiotropy residual sum and outlier (MR-PRESSO), Cochran Q statistic, and leave-one-out analysis were used to detect and correct for the effect of heterogeneity and horizontal pleiotropy.

Results

MR analysis indicated that GERD was causally associated with an increased risk of COPD (IVW odds ratio (OR): 1.3760, 95% confidence interval (CI): 1.1565-1.6371, P=0.0003), and vice versa (IVW OR: 1.1728, 95% CI:1.0613-1.2961, P=0.0018). The analyses did not reveal any pleiotropy or heterogeneity.

Conclusion

Our study revealed possible evidence for a bidirectional causal relationship between GERD and COPD. Implementing screening and preventive strategies for GERD in individuals with COPD, and vice versa, will be crucial in future healthcare management. Further studies are needed to elucidate the mechanisms underlying the causal relationship between GERD and COPD.

Associations of fatty acids with the risk of biliary tract calculus and inflammation: a Mendelian randomization study

BACKGROUND

The presence of gallstones in both the gallbladder and bile ducts is referred to as cholelithiasis. The prevalence of cholecystolithiasis and bile duct stones differs. Observational and Mendelian randomization (MR) studies have elucidated the significant contributing role of numerous fatty acids (FAs) in the development of cholelithiasis. Despite numerous studies about cholelithiasis, evidence on the relationship between serum FA levels and cholecystolithiasis, as well as bile duct stones with or without inflammation, remains insufficient.

METHODS

A two-sample MR study was designed to clarify the impact of serum FA levels on various bile duct inflammatory diseases. The summary statistics of single nucleotide polymorphisms (SNPs) associated with fatty acids were obtained from the UK Biobank (UKB) and included data from 114,999 participants. The researchers obtained GWAS summary statistics for cholecystolithiasis and bile duct stones in 463,010 and 361,194 European participants, including cases with and without inflammation. No sample overlap between the exposure and outcome was verified through the "mr-lap" package. The SNPs were screened to identify instrumental variables (IVs). Cochran's Q test was applied for heterogeneity assessment. Inverse variance weighting (IVW) (fixed effects or random effects), MR-Egger regression and weighted median methods were used for MR. Multivariable MR was applied to determine the direct effect of each exposure on the outcome. A false discovery rate (FDR) was applied to adjust for multiple testing correction based on the Benjamini-Hochberg method. Finally, the FinnGen Consortium was used to validate some results.

RESULTS

The overall concentration of polyunsaturated fatty acids (PUFAs) in the serum was negatively associated with the risk of calculus of the gallbladder with acute cholecystitis (IVW, OR = 0.996, P = 0.038, CI 0.992-0.999; weighted median, OR = 0.995, P = 0.025, CI 0.991-0.999). The percentage of PUFAs to total monounsaturated fatty acids(MUFAs) (IVW, OR = 0.998, P = 0.045, CI 0.997-0.999) and the percentage of PUFAs to total FAs (IVW, OR = 0.997, P = 0.025, CI 0.995-0.999) had a protective role against cholecystitis. The percentage of PUFAs to total FAs had a protective role against calculus of the gallbladder without cholecystitis (IVW, OR = 0.995, P = 0.026, CI 0.990-0.999; MR Egger, OR = 0.99, P = 0.03, CI 0.982-0.998; weighted median, OR = 0.991, P = 5.41e-06, CI 0.988-0.995). Conversely, the percentage of MUFAs to total FAs increased the risk for cholecystitis (IVW, OR = 1.001, P = 0.034, CI 1.0001-1.002). However, there were no causal effects of the above exposures on the outcomes through multivariable MR and multiple testing correction. Finally, the causal effects of the above exposures on cholecystitis were validated in the FinnGen Consortium, which suggested that the percentage of PUFAs to total FAs (IVW, OR = 0.744, P = 0.021, CI 0.579-0.957) had a protective role against cholecystitis.

CONCLUSION

These Mendelian randomization findings suggested that more attention should be focused on people who have low serum PUFA levels, which may have a potential role in the occurrence of calculus of the gallbladder or cholecystitis rather than calculus of the bile duct without cholangitis or cholecystitis.

Understanding the consequences of leisure sedentary behavior on periodontitis: A two-step, multivariate Mendelian randomization study

Background

The relationship between leisure sedentary behavior (LSB) and periodontitis risk remains unclear in terms of causality and the potential mediating effects of intermediate factors.

Materials and methods

Using the aggregate data of several large-scale genetic association studies from participants of European descent, we conducted a univariate, two-step, and multivariate Mendelian random (MR) analysis to infer the overall effect of LSB on periodontitis, and quantified the intermediary proportion of intermediary traits such as smoking.

Results

Our findings indicated that per 1-SD increase (1.87 h) in leisure screen time (LST), there was a 23 % increase in the risk of periodontitis. [odds ratios (95 % CI) = 1.23 (1.04-1.44), p = 0.013]. Smoking was found to partially mediate the overall causal effect of LST on periodontitis, with a mediation rate of 20.7 % (95 % CI: 4.9%-35.5 %). Multivariate MR analysis demonstrated that the causal effect of LST on periodontitis was weakened when adjusting for smoking, resulting in an odds ratio of 1.19 (95 % CI: 1.01-1.39, p = 0.049) for each 1 standard deviation increase in exposure.

Conclusion

The study provides evidence of a potential causal relationship between LSB characterized by LST and periodontitis, thereby further supporting the notion that reducing LSB is beneficial for health. Furthermore, it confirms the role of smoking as a mediator in this process, suggesting that inhibiting smoking behavior among individuals with long-term LSB may serve as a strategy to mitigate the risk of periodontitis.

Causality between depression and ankylosing spondylitis in a European population: Results from a Mendelian randomization analysis

The aim of this study was to explore the application of Mendelian randomization (MR) Egger and inverse variance weighted (IVW) in a causal effect on depression and ankylosing spondylitis (AS). Instrumental variables (IVs) were determined using genome-wide association studies. The 2-sample MR analysis was conducted by MR Egger to test the causal effect between depression and AS. The pleiotropy of potential instrumental variables was evaluated. The results of MR Egger and IVW were further compared. A total of 3 single nucleotide polymorphisms as the construct IVs were included. IVW results showed a significant causal effect between depression and AS (P < .001). Depression could promote the risk of AS (odds ratio = 1.060, 95% confidence interval: 1.026-1.094). However, the MR Egger showed no causal effect (P = .311). Heterogeneity statistics suggested that no heterogeneity was existed (P > .05). It was also suggested that there was no horizontal pleiotropy in IVs (MR Egger intercept: -0.0004, P = .471). Reverse MR analysis suggested that there was no causal effect between AS and depression (P > .05). Gene expression quantitative trait locus (QTLs) suggested that rs2517601 and RNF39 were positively correlated (beta = 1.066, P < .001). Depression may be one of the causes of AS by MR analysis in a European population. We can estimate the causal effect based on IVW when horizontal pleiotropy is very tiny.

Unraveling the metabolic underpinnings of frailty using multicohort observational and Mendelian randomization analyses

Identifying metabolic biomarkers of frailty, an age-related state of physiological decline, is important for understanding its metabolic underpinnings and developing preventive strategies. Here, we systematically examined 168 nuclear magnetic resonance-based metabolomic biomarkers and 32 clinical biomarkers for their associations with frailty. In up to 90,573 UK Biobank participants, we identified 59 biomarkers robustly and independently associated with the frailty index (FI). Of these, 34 associations were replicated in the Swedish TwinGene study (n = 11,025) and the Finnish Health 2000 Survey (n = 6073). Using two-sample Mendelian randomization, we showed that the genetically predicted level of glycoprotein acetyls, an inflammatory marker, was statistically significantly associated with an increased FI (β per SD increase = 0.37%, 95% confidence interval: 0.12-0.61). Creatinine and several lipoprotein lipids were also associated with increased FI, yet their effects were mostly driven by kidney and cardiometabolic diseases, respectively. Our findings provide new insights into the causal effects of metabolites on frailty and highlight the role of chronic inflammation underlying frailty development.