Based on the traditional Chinese medicine(TCM) theory of "kidney-brain interaction", a two-sample Mendelian randomization(MR) analysis was conducted to investigate the causal effects of chronic kidney disease(CKD) on Alzheimer's disease(AD) and analyze the potential mechanisms of kidney-tonifying and essence-replenishing TCM to improve AD. From the perspective that CKD is closely related to the core pathogenesis of AD, namely "kidney deficiency, essence loss, and marrow reduction", genome-wide association study(GWAS) data was used, with the inverse variance weighting(IVW) method as the main approach to reveal the causal association between CKD and AD. Sensitivity analysis was conducted to evaluate the robustness of the results. To further investigate the causal effects of CKD on AD, two different AD datasets were used as outcomes, and the urinary albumin-to-creatinine ratio(UACR) data was used as the exposure for a supplementary analysis. On this basis, the modern scientific mechanism of the kidney-tonifying and essence-replenishing method for improving AD was further explored. The IVW analysis show that CKD(ieu-b-2: OR=1.084, 95%CI[1.011, 1.163], P=0.024; ieu-b-5067: OR=1.001, 95%CI[1.000, 1.001], P=0.002) and UACR(ieu-b-2: OR=1.247, 95%CI[1.021, 1.522], P=0.031; ieu-b-5067: OR=1.001, 95%CI[1.000, 1.003], P=0.015) both have significant causal effects on AD in different datasets, with CKD increasing the risk of AD. The sensitivity analysis further confirmed the reliability of the results. Genetic studies have shown that CKD has a significant causal effect on AD, suggesting that controlling CKD is an important intervention measure for preventing and treating AD. Therefore, further research on CKD's role in AD is crucial in clinical practice. The research enriches the theoretical implication of "kidney-brain interaction", deepens the understanding of AD' etiology, and provides further insights and directions for the prevention and treatment of AD with TCM, specifically from a kidney-based perspective.
Humans ; Alzheimer Disease/genetics* ; Renal Insufficiency, Chronic/genetics* ; Kidney/metabolism* ; Brain/physiopathology* ; Genome-Wide Association Study ; Medicine, Chinese Traditional ; Mendelian Randomization Analysis

OBJECTIVES: To clarify the causal relationship between the level of cytoplasmic unactivated mineralocorticoid receptor (MR) and the development of tubulointerstitial nephritis (TIN), and to evaluate the impact of MR on dyslipidemia, particularly secondary hyperlipemia, in patients with diabetic kidney disease. METHODS: We conducted a two-sample Mendelian randomization study using genome-wide association study (GWAS) summary data. Genetic variants associated with MR levels were selected as exposures, with TIN and lipid profiles [including low-density lipoprotein cholesterol (LDL-C), triglyceride, and high-density lipoprotein cholesterol] as outcomes. A two-step Mendelian randomization approach was used to assess TIN as a mediator, employing inverse variance weighted regression as the primary analysis, supplemented by Mendelian randomization-Egger, weighted median, and sensitivity analyses. RESULTS: Cytoplasmic unactivated MR level exhibited a significant causal association with a decreased risk of TIN (OR = 0.8598, 95% CI [0.7775-0.9508], P < 0.001). Although no significant causal relationship was identified between MR level and secondary hyperlipemia, a potential association of cytoplasmic unactivated MR level with lower LDL-C levels was observed (OR = 0.9901, 95% CI [0.9821-0.9983], P = 0.018). Additionally, TIN exhibited causal links with secondary hyperlipemia (OR = 1.0016, 95% CI [1.0002-1.0029], P = 0.020) and elevated LDL-C (OR = 1.0111, 95% CI [1.0024-1.0199], P = 0.012), particularly LDL-C in European males (OR = 1.0230, 95% CI [1.0103-1.0358], P < 0.001). Inverse Mendelian randomization analysis revealed causal relationships between TIN and genetically predicted triglyceride (OR = 0.7027, 95% CI [0.6189-0.7978], P < 0.001), high-density lipoprotein cholesterol (OR = 1.1247, 95% CI [1.0019-1.2626], P = 0.046), and LDL-C (OR = 0.8423, 95% CI [0.7220-0.9827], P = 0.029). Notably, TIN mediated 16.7% of the causal association between MR and LDL-C levels. CONCLUSIONS MR plays a critical role in the development of TIN and lipid metabolism, highlighting the potential of MR-antagonists in reducing renal damage and lipid metabolism-associated complications.
Humans ; Mendelian Randomization Analysis ; Nephritis, Interstitial/metabolism* ; Receptors, Mineralocorticoid/genetics* ; Lipid Metabolism/genetics* ; Genome-Wide Association Study ; Male ; Female ; Polymorphism, Single Nucleotide ; Dyslipidemias/metabolism*

OBJECTIVE: To explore the potential causal relationship between intervertebral disc degeneration and certain autoimmune diseases. METHODS: Genome-wide association study (GWAS) data of 5 autoimmune diseases were obtained from large-scale GWAS databases. Data on internal vertebral disc degeneration (IVDD) were derived from the FinnGen consortium, which included 294, 770 controls and 41, 669 cases. A two-sample bidirectional Mendelian randomization (MR) analysis was performed to investigate the potential causal relationship between the 5 autoimmune diseases and IVDD. Multiple analytical methods were adopted, including MR methods such as inverse variance weighting(IVW), MR-Egger, weighted median, weighted mode, and simple mode. Cochran's Q test, leave-one-out analysis, and MR-Egger intercept test were conducted to assess heterogeneity, robustness, and pleiotropy. For the robustness of the results, MR-PRESSO was used to detect outliers, and MR analysis was re-conducted after removing the outliers. RESULTS: The MR analysis results showed that there might be a bidirectional causal relationship between ankylosing spondylitis(AS) and IVDD:AS on IVDD, OR=1.038, 95%CI (1.024, 1.053), P=0.000;and IVDD on AS, OR=2.117, 95%CI(1.065, 4.207), P=0.032. There might be a positive correlation between IVDD and rheumatoid arthritis(RA) as well as systemic lupus erythematosus(SLE):IVDD on RA, OR=1.184, 95%CI(1.071, 1.309), P=0.001;and IVDD on SLE, OR=1.678, 95%CI(1.187, 2.372), P=0.003. There was no significant correlation between ulcerative colitis(UC), autoimmune thyroiditis(ATD) and IVDD. After removing outliers by MR-PRESSO and re-conducting MR analysis, the results did not change qualitatively. Sensitivity analysis indicated that the results were robust to potential sources of bias. CONCLUSION AS and IVDD may be risk factors for each other, and IVDD may be a potential risk factor for RA and SLE. These findings provide a basis for guiding the prevention and combined diagnosis and treatment of IVDD, AS, RA, and SLE, while the specific underlying mechanisms still require further experimental basic research.
Humans ; Intervertebral Disc Degeneration/etiology* ; Mendelian Randomization Analysis ; Autoimmune Diseases/complications* ; Genome-Wide Association Study ; Spondylitis, Ankylosing/genetics* ; Arthritis, Rheumatoid/genetics*

OBJECTIVES: To analyze the potential causal relationship between gut microbiota and food allergy (FA) using two-sample Mendelian randomization (MR) methods. METHODS: Data from genome-wide association studies on gut microbiota and FA were utilized. MR analysis was conducted employing inverse variance weighting, MR-Egger regression, and weighted median methods to assess the causal relationship between gut microbiota and FA. Cochrane's Q test was used to evaluate heterogeneity of instrumental variables, MR-PRESSO analysis was conducted to test for outliers and pleiotropy, and MR-Egger regression was employed to assess horizontal pleiotropy. The "leave-one-out" method was used to evaluate the impact of removing individual single nucleotide polymorphisms on the causal relationship. RESULTS: Inverse variance weighting analysis revealed that the phylum Verrucomicrobia, family Verrucomicrobiaceae, order Verrucomicrobiales, genus Ruminococcaceae UCG013, and genus Akkermansia were negatively associated with FA (P<0.05). Sensitivity analyses confirmed the reliability of the findings, indicating no heterogeneity or pleiotropy present. CONCLUSIONS There is a causal relationship between gut microbiota and FA, with Verrucomicrobia, Verrucomicrobiaceae, Verrucomicrobiales, Ruminococcaceae UCG013, and Akkermansia potentially reducing the risk of developing FA. These findings provide potential targets for the treatment and prevention of FA; however, further research is needed to explore the specific mechanisms by which the microbiota influence FA.
Humans ; Mendelian Randomization Analysis ; Gastrointestinal Microbiome ; Food Hypersensitivity/microbiology* ; Genome-Wide Association Study ; Polymorphism, Single Nucleotide

OBJECTIVES: To evaluate the causal association between circulating levels of zinc, magnesium, and other minerals and autism spectrum disorder (ASD). METHODS: A two-sample Mendelian randomization (MR) analysis was performed using summary statistics from large-scale genome-wide association studies of European populations, including 18 382 ASD cases and 27 969 controls. Genetic data for iron, calcium, and magnesium were obtained from the UK Biobank, and data for zinc and selenium were sourced from an Australian-British cohort. A total of 351 genetic instrumental variables were selected. Causal inference was performed using inverse-variance weighting as the primary analysis method. Sensitivity analyses were performed by Cochran's Q test and MR-PRESSO global test to assess the robustness of the findings. RESULTS: No statistically significant causal effect was observed for circulating zinc, magnesium, calcium, selenium, or iron levels on ASD risk (all P>0.05). The odds ratios and 95% confidence intervals from the inverse-variance weighting analysis were 0.934 (0.869-1.003) for zinc, 1.315 (0.971-1.850) for magnesium, 1.055 (0.960-1.159) for calcium, 1.015 (0.953-1.080) for selenium, and 0.946 (0.687-1.303) for iron. Sensitivity analysis revealed significant heterogeneity in the causal association between circulating calcium and ASD (P=0.006), while the effect estimate remained stable after MR-PRESSO correction (P=0.487). The causal effect estimates for the remaining minerals demonstrated good robustness. CONCLUSIONS This study did not find significant evidence supporting a causal association between circulating zinc, magnesium, calcium, selenium, or iron levels and ASD risk, providing important clues for the etiology of ASD and precision nutritional interventions.
Humans ; Mendelian Randomization Analysis ; Autism Spectrum Disorder/genetics* ; Magnesium/blood* ; Zinc/blood* ; Minerals/blood* ; Genome-Wide Association Study ; Selenium/blood*

OBJECTIVE: To investigate the genetic causal relationship of leukocyte telomere length (LTL) with prostatitis, orchitis and epididymitis by two-sample Mendelian randomization (MR). METHODS: Using LTL as the exposure factor and prostatitis, orchitis and epididymitis as outcome factors, we mined the Database of Genome-Wide Association Studies (GWAS). Then, we analyzed the causal relationship of LTL with prostatitis, orchitis and epididymitis by Mendelian randomization using inverse variance weighting (IVW) as the main method and weighted median and MR-Egger regression as auxiliary methods, determined the horizontal multiplicity by MR-Egger intercept test, and conducted sensitivity analysis using the leaving-one-out method. RESULTS: A total of 121 related single nucleotide polymorphisms (SNPs) were identified in this study. IVW showed LTL to be a risk factor for prostatitis (OR = 1.383, 95% CI: 1.044－1.832, P = 0.024), and for orchitis and epididymitis as well (OR = 1.770, 95% CI: 1.275－2.456, P = 0.000 6). CONCLUSION Genetic evidence from Mendelian randomized analysis indicates that shortening of LTL reduces the risk of prostatitis, orchitis and epididymitis.
Humans ; Male ; Mendelian Randomization Analysis ; Epididymitis/genetics* ; Prostatitis/genetics* ; Polymorphism, Single Nucleotide ; Leukocytes ; Orchitis/genetics* ; Genome-Wide Association Study ; Telomere ; Risk Factors

Objective： To investigate the relationship between the lipid metabolism-related gene sterol carrier protein 2(SCP2) and prostate cancer (PCa) from a multi-omics perspective using single-cell transcriptomes combined with Mendelian randomization. Methods： Single-cell transcriptome data of benign and malignant prostate tissues were obtained from GSE120716, GSE157703 and GSE141445 datasets, respectively. Integration, quality control and annotation were performed on the data to categorize the epithelial cells into high and low SCP2 expression groups, followed by further differential and trajectory analyses. Single nucleotide polymorphism (SNP) data for SCP2 expression quantitative trait loci (eQTL) were subsequently downloaded from Genotype-Tissue Expression (GTEx) and investigated from the PCa Society Cancer-Related Genomic Alteration Panel for the Investigation of Cancer-Related Alterations (PRACTICAL) to obtain PCa outcome data for Mendelian randomization analysis to validate the causal relationship between SCP2 and PCa. Results： High SCP2-expressing epithelial cells had higher energy metabolism and proliferation capacity with low immunotherapy response and metastatic tendency. Trajectory analysis showed that epithelial cells with high SCP2 expression may have a higher degree of malignancy, and SCP2 may be a key marker gene for differentiation of malignant epithelial cells in the prostate. Further Mendelian randomization results showed a significant causal relationship between SCP2 and PCa development (OR=1.045, 95% CI: 1.010 －1.083, P=0.011). Conclusion： By combining single-cell transcriptome and Mendelian randomization, the role of the lipid metabolism-related gene SCP2 in PCa development has been confirmed, and new targets and therapeutic directions for PCa treatment have been provided.
Humans ; Prostatic Neoplasms/genetics* ; Male ; Mendelian Randomization Analysis ; Polymorphism, Single Nucleotide ; Quantitative Trait Loci ; Single-Cell Analysis ; Sequence Analysis, RNA ; Carrier Proteins/genetics* ; Transcriptome ; Lipid Metabolism

OBJECTIVE: Previous studies have shown that insomnia is closely related to erectile dysfunction（ED）. However, the causal relationship between them is still unclear. Mendelian randomization (MR) provides a new method for studying the relationship between the two, and the theory of heart-kidney interaction in TCM provides a new idea for exploring the causal relationship between them. METHODS: Based on the statistical data collected by genome-wide association studies (GWAS), the causal relationship between insomnia and ED was discussed by MR. Inverse variance weighted (IVW) is the main analysis method, and weighted median (WME), simple mode (SM), weighted mode (WM) and MR Egger method were the supplementary analysis to evaluate the causal effect. MR-Egger intercept test, Cochran Q test and leave-one-out method were used in sensitivity analysis to verify the reliability of MR results. RESULTS: Thirty-nine SNPs significantly related to insomnia were finally included for MR analysis. The results of IVW method in MR analysis showed that insomnia had a significant causal relationship with the increased risk of ED (OR = 3.111，95% CI= 1.566－6.181，P=1.193×10－3). The results obtained by MR-Egger method, WME method, WM method and SM method were consistent with IVW method in the direction of effect. The sensitivity results suggested that the results of this study were robust. CONCLUSION Our study reveals the causal relationship between insomnia and ED, which provides a new basis for future clinical practice and prevention and treatment of ED.
Causality ; Sleep Initiation and Maintenance Disorders/genetics* ; Erectile Dysfunction/genetics* ; Mendelian Randomization Analysis ; Genome-Wide Association Study ; Humans ; Male ; Heart/physiology* ; Kidney/physiology* ; Polymorphism, Single Nucleotide ; Data Interpretation, Statistical

OBJECTIVE: To evaluate the association between erectile dysfunction (ED) and myocardial infarction (MI) using two sample Mendelian randomization. METHODS: A Mendelian randomization study was conducted using comprehensive data on ED and MI from extensive genome-wide association data. Using inverse variance weighted analysis for causal relationships, and correct for confounding factors using multivariate Mendelian randomization, the potential mediating effects were evaluated as well. Based on Genecard data, the genes related to ED and MI were identified. Molecular docking was used to reveal spontaneously bound drug molecules. RESULTS: Our study found that exposure to ED was a risk factor for MI (OR: 1.001 0, 95% CI: 1.000 2－1.001 8, P=0.017 7), which also held true in the validation dataset (OR: 1.028 5, 95% CI: 1.005 0－1.052 6, P=0.017 2). No statistically significant heterogeneity or horizontal pleiotropy was found. The results of reverse Mendelian randomization analysis showed any reverse causal relationship between ED and MI. In multivariate Mendelian randomization analysis, after excluding confounding factors (excluding triglycerides and high-density lipoprotein), the P-value remained less than 0.05, and the OR ranged from 1.000 1 to 1.000 7, indicating that ED was still a risk factor for MI. In the mediation analysis, it was found that the current mediation ratio of smoking to MI was 13.06%. In summary-data-based mendelian randomization analysis, it was found that the gene PTPN11 was a common target gene for MI and ED (OR=0.990, P<0.001). Subsequent molecular docking with sildenafil, clopidogrel, and dapoxetine could spontaneously bind to the PTPN11 gene receptor. CONCLUSION There is a causal relationship between ED and MI, with smoking as a potential mediating factor, and the gene PTPN11 being a co-target gene.
Humans ; Male ; Mendelian Randomization Analysis ; Myocardial Infarction/genetics* ; Erectile Dysfunction/complications* ; Risk Factors ; Genome-Wide Association Study ; Molecular Docking Simulation ; Polymorphism, Single Nucleotide

OBJECTIVES: The gut microbiota plays a crucial role in the pathophysiology of various types of diabetes. However, the causal relationship between them has yet to be systematically elucidated. This study aims to explore the potential causal associations between gut microbiota and diabetes using a two-sample Mendelian randomization (MR) analysis, based on multiple taxonomic levels. METHODS: Eligible instrumental variables were extracted from the selected genome-wide association study (GWAS) data on gut microbiota. These were combined with GWAS datasets on type 1 diabetes (T1D), type 2 diabetes (T2D), and gestational diabetes mellitus (GDM) to conduct forward MR analysis, sensitivity analysis, reverse MR analysis, and validation of significant estimates. Microbial taxa with causal effects on T1D, T2D, and GDM were identified based on a comprehensive assessment of all analytical stages. RESULTS: A total of 2 179, 2 176, and 2 166 single nucleotide polymorphisms (SNP) were included in the MR analyses for gut microbiota with T1D, T2D, and GDM, respectively. MR results indicated causal associations between: Six microbial taxa (Eggerthella, Lachnospira, Bacillales, Desulfovibrionales, Parasutterella, and Turicibacter) and T1D; 9 microbial taxa (Verrucomicrobia, Deltaproteobacteria, Actinomycetales, Desulfovibrionale, Actinomycetaceae, Desulfovibrionaceae, Actinomyces, Alcaligenaceae, and Lachnospiraceae NC2004 group) and T2D; 10 microbial taxa (Betaproteobacteria, Coprobacter, Ruminococcus2, Tenericutes, Clostridia, Methanobacteria, Mollicutes, Methanobacteriales, Methanobacteriaceae, and Methanobrevibacter) and GDM. CONCLUSIONS This study identified specific gut microbial taxa that may significantly increase or decrease the risk of developing diabetes. Some findings were fully replicated in independent validation datasets. However, the underlying biological mechanisms of these causal relationships warrant further investigation through mechanistic studies and population-based research.
Gastrointestinal Microbiome/genetics* ; Humans ; Mendelian Randomization Analysis ; Genome-Wide Association Study ; Diabetes Mellitus, Type 2/genetics* ; Diabetes Mellitus, Type 1/genetics* ; Female ; Polymorphism, Single Nucleotide ; Diabetes, Gestational/genetics* ; Pregnancy