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*

OBJECTIVES: To investigate the causal associations between autoimmune diseases and aplastic anemia (AA) using Mendelian randomization analysis. METHODS: Publicly available genome-wide association study (GWAS) data were utilized to obtain single nucleotide polymorphisms (SNPs) associated with autoimmune diseases and AA for analysis. The inverse variance weighted (IVW) method was employed as the primary analytical approach, with MR Egger, Weighted Mode, Weighted Median, and Simple Mode methods serving as complementary analyses. Heterogeneity and pleiotropy analyses were conducted using designated functions, and the robustness of Mendelian randomization results was assessed using leave-one-out analysis. RESULTS: The two-sample Mendelian randomization analysis using the IVW method revealed significant positive causal associations of rheumatoid arthritis (OR=1.094, 95% CI: 1.023-1.170, P=0.009, adjusted P=0.042), systemic lupus erythematosus (OR=1.111, 95% CI: 1.021-1.208, P=0.015, adjusted P=0.036), Hashimoto thyroiditis (OR=1.206, 95% CI: 1.049-1.387, P=0.009, adjusted P=0.029), and Sicca syndrome (OR=1.173, 95% CI: 1.054-1.306, P=0.004, adjusted P=0.035) with AA, which was supported by the results from the Weighted Median method. Sensitivity analyses indicated no evidence of pleiotropy or heterogeneity, and leave-one-out analysis confirmed the robustness of the causal relationships. No direct evidence was found linking Graves' disease, ulcerative colitis, Crohn's disease, autoimmune hepatitis, primary biliary cholangitis, or primary sclerosing cholangitis with AA (P>0.05, adjusted P>0.05), indicating a lack of causal association. Reverse Mendelian randomization results and multiple corrections indicated that AA was not an influencing factor for autoimmune diseases (adjusted P>0.05). CONCLUSIONS Our findings support at the genetic level that rheumatoid arthritis, systemic lupus erythematosus, Hashimoto thyroiditis, and Sicca syndrome are risk factors for AA, and confirm a causal association of the these 4 autoimmune diseases with an increased risk of AA.
Humans ; Mendelian Randomization Analysis ; Anemia, Aplastic/genetics* ; Autoimmune Diseases/complications* ; Polymorphism, Single Nucleotide ; Genome-Wide Association Study ; Arthritis, Rheumatoid/genetics* ; Lupus Erythematosus, Systemic/genetics* ; Genetic Predisposition to Disease

OBJECTIVES: To analyze the changes in disease burden and risk factors of atrial fibrillation/atrial flutter (AF/AFL) in China and globally from 1990 to 2021 to provide epidemiological evidence for developing effective preventive measures for AF/AFL in China. METHODS: Based on data from the Global Burden of Disease Study 2021, we analyzed sex- and age-specific AF/AFL burden metrics across 204 countries or territories. Age-standardized incidence rate (ASIR), prevalence, mortality rate (ASMR), and disability-adjusted life-years (DALYs) rate (ASDR) were calculated. Joinpoint regression was employed to compute average annual percentage changes (AAPC) in trends. The risk factors were systematically evaluated and further validated using Mendelian randomization analysis. RESULTS: From 1990 to 2021, China experienced an increase in ASIR of AF/AFL (from 42.63 to 44.93 per 100 000), contrasting with the global decline. While China's ASMR decreased (from 4.93 to 4.33 per 100 000), global ASMR rose slightly (from 4.24 to 4.36 per 100 000). China's ASDR remained stable at 93.29 per 100 000, whereas global ASDR increased marginally (100.81 to 101.40 per 100 000). Significant sex disparities were observed: males showed higher ASIR and ASDR, while females exhibited greater ASMR and ASDR. China had higher incidence and prevalence but lower mortality and DALY rates compared to global averages. In 2021, the key risk factors for AF/AFL included elevated systolic blood pressure, high BMI, smoking, alcohol use, high-sodium diet, and low temperature. Gender-specific patterns emerged: smoking was predominant in males, whereas high BMI disproportionately affected females. CONCLUSIONS AF/AFL incidence and prevalence keep increasing in China, and its large population base and demographic aging pose significant public health challenges. Maintaining healthy lifestyle habits, including smoking cessation, alcohol moderation, and a low-sodium diet can help to lower AF/AFL incidence, and regular screenings is crucial for its early detection and treatment.
Humans ; China/epidemiology* ; Risk Factors ; Atrial Flutter/epidemiology* ; Atrial Fibrillation/epidemiology* ; Mendelian Randomization Analysis ; Male ; Female ; Global Burden of Disease ; Incidence ; Prevalence ; Middle Aged ; Disability-Adjusted Life Years ; Aged

OBJECTIVES: To investigate the causal relationship between gut microbiota and kidney stones. METHODS: Mendelian randomization analysis was conducted based on data from the MiBioGen consortium gut microbiota GWAS (exposure factors) and the IEU Open GWAS kidney stone dataset ukb-b-8297 (outcome variables) using the inverse variance weighted, MR-Egger regression, weighted median, weighted mode, and simple mode methods. Heterogeneity, pleiotropy, and leave-one-out sensitivity analyses were also performed. In the animal experiment, 12 male SD rats were randomized into control group with saline treatment and kidney stone model group treated with 1% ethylene glycol and 2% ammonium chloride for 28 consecutive days. Urine, blood, and intestinal samples of the rats were collected for testing the changes in renal function and intestinal barrier-related indicators, and kidney and colon pathologies were examined with histological staining and immunohistochemistry. The changes in diversity and abundance of gut microbiota were analyzed using 16S rRNA gene sequencing. RESULTS: Mendelian randomization analysis showed that decreased abundances of Lachnospiraceae NK4A136 group (OR=0.9974, 95% CI: 0.9948-0.9999, P=0.0393) and Gordonibacter (OR=0.9987, 95% CI: 0.9974-0.9999, P=0.0403) were associated with an increased risk of kidney stones without significant heterogeneity or horizontal pleiotropy, and sensitivity analyses suggested robustness of the results. The rat models of kidney stones exhibited significant renal function impairment and calcium oxalate crystal deposition, accompanied by decreased expressions of intestinal barrier-related proteins with lowered intestinal α- and β-diversity indices. Intestinal Gordonibacter abundance was significantly reduced in the rat models while the Lachnospiraceae NK4A136 group did not differ significantly between the control and model groups. CONCLUSIONS Decreased Gordonibacter abundance in gut microbiota is associated with an increased risk of kidney stones. The protective role of the Lachnospiraceae NK4A136 group against kidney stones as suggested by Mendelian randomization analysis fails to be supported by the experimental evidence and awaits further investigation.
Animals ; Kidney Calculi/microbiology* ; Gastrointestinal Microbiome ; Mendelian Randomization Analysis ; Rats, Sprague-Dawley ; Rats ; Male ; Disease Models, Animal ; Intestines/microbiology* ; RNA, Ribosomal, 16S/genetics*

This study aimed to comprehensively examine the association of gallstones, cholecystectomy, and cancer risk. Multivariable logistic regressions were performed to estimate the observational associations of gallstones and cholecystectomy with cancer risk, using data from a nationwide cohort involving 239 799 participants. General and gender-specific two-sample Mendelian randomization (MR) analysis was further conducted to assess the causalities of the observed associations. Observationally, a history of gallstones without cholecystectomy was associated with a high risk of stomach cancer (adjusted odds ratio (aOR)=2.54, 95% confidence interval (CI) 1.50-4.28), liver and bile duct cancer (aOR=2.46, 95% CI 1.17-5.16), kidney cancer (aOR=2.04, 95% CI 1.05-3.94), and bladder cancer (aOR=2.23, 95% CI 1.01-5.13) in the general population, as well as cervical cancer (aOR=1.69, 95% CI 1.12-2.56) in women. Moreover, cholecystectomy was associated with high odds of stomach cancer (aOR=2.41, 95% CI 1.29-4.49), colorectal cancer (aOR=1.83, 95% CI 1.18-2.85), and cancer of liver and bile duct (aOR=2.58, 95% CI 1.11-6.02). MR analysis only supported the causal effect of gallstones on stomach, liver and bile duct, kidney, and bladder cancer. This study added evidence to the causal effect of gallstones on stomach, liver and bile duct, kidney, and bladder cancer, highlighting the importance of cancer screening in individuals with gallstones.
Humans ; Mendelian Randomization Analysis ; Gallstones/complications* ; Female ; Male ; Cholecystectomy/statistics & numerical data* ; Middle Aged ; Risk Factors ; Aged ; Adult ; Neoplasms/etiology* ; Stomach Neoplasms/epidemiology*

OBJECTIVE: To investigate the potential mechanisms of sepsis pathogenesis in intensive care unit (ICU), with a specific focus on the role of skin microbiota, and to evaluate the causal relationships between skin microbiota and ICU sepsis using Mendelian randomization (MR). METHODS: A two-sample MR analysis was performed using skin microbiota genome-wide association study (GWAS) summary data from German population cohorts as exposures, combined with ICU sepsis susceptibility and 28-day mortality GWAS summary data from the IEU OpenGWAS database as outcomes. The primary causal effect estimates were generated using the inverse variance weighted (IVW) method, supplemented by validation through MR-Egger and weighted median approaches. Heterogeneity and pleiotropy tests, along with sensitivity analyses, were conducted to evaluate the robustness of the results. RESULTS: Regarding risk of ICU sepsis, IVW analysis showed that order Pseudomonadales [odds ratio (OR) = 0.93, 95% confidence interval (95%CI) was 0.88-0.98], family Flavobacteriaceae (OR = 0.93, 95%CI was 0.90-0.96), and genus Acinetobacter (OR = 0.96, 95%CI was 0.93-0.99) were significantly negatively correlated with the risk of ICU sepsis (all P < 0.05). There was a significant positive correlation between the risk of ICU sepsis and the presence of β-Proteobacteria (OR = 1.05, 95%CI was 1.00-1.11) and Actinobacteria (OR = 1.05, 95%CI was 1.00-1.11), both P < 0.05. Regarding 28-day mortality of ICU sepsis, IVW analysis showed that phylum Bacteroidetes (OR = 0.92, 95%CI was 0.86-0.99), family Streptococcaceae (OR = 0.92, 95%CI was 0.85-0.98), family Flavobacteriaceae (OR = 0.90, 95%CI was 0.83-0.97), genus Streptococcus (OR = 0.92, 95%CI was 0.86-0.99), ASV016 [Enhydrobacter] (OR = 0.92, 95%CI was 0.87-0.98), and ASV042 [Acinetobacter] (OR = 0.92, 95%CI was 0.88-0.97) were significantly negatively correlated with the 28-day mortality of ICU sepsis (all P < 0.05); family Moraxellaceae (OR = 1.09, 95%CI was 1.00-1.18) and ASV008 [Staphylococcus] (OR = 1.08, 95%CI was 1.03-1.14) was significantly positively correlated with the 28-day mortality of ICU sepsis (both P < 0.05). Sensitivity analysis and MR-PRESSO showed no heterogeneity, pleiotropy, or horizontal pleiotropy between skin microbiota and ICU sepsis risk and 28-day mortality rate. Analysis of confounding factors showed that single nucleotide polymorphisms (SNPs) associated with relevant skin bacteria could independently and causally affect the risk of ICU sepsis or ICU sepsis related mortality rate, independent of other confounding factors. The Steiger test results indicated that the established causal relationship was not due to reverse causality. CONCLUSIONS Skin microbiota composition may influence both sepsis susceptibility and 28-day mortality in ICU settings. Family Flavobacteriaceae demonstrated protective effects against sepsis onset and mortality. These findings provide new perspectives for early detection and management strategies.
Humans ; Sepsis/mortality* ; Intensive Care Units ; Mendelian Randomization Analysis ; Microbiota ; Skin/microbiology* ; Genome-Wide Association Study ; Risk Factors ; Skin Microbiome