Smoking, alcohol consumption, and 24 gastrointestinal diseases: Mendelian randomization analysis

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).

A novel nomogram for predicting the morbidity of chronic atrophic gastritis based on serum CXCL5 levels

OBJECTIVE

This study aimed to investigate the diagnostic potential of serum CXC chemokine ligand 5 (CXCL5) in patients with chronic atrophic gastritis (CAG) and to establish a prediction model for better diagnosis of CAG.

METHODS

A retrospective analysis was conducted, encompassing 570 cases of CAG patients admitted to the Department of Gastroenterology of the Second Affiliated Hospital of Anhui University of Traditional Chinese Medicine, who underwent gastroscopy and received pathologically confirmed diagnoses between June 2018 and June 2023. Additionally, 570 cases without CAG who underwent health checkups were included and classified into the control group. Single-factor and multi-factorial logistic regression analyses were employed to identify risk factors of CAG, and a prediction model for diagnosing CAG was developed using R software. The predictive performance of the constructed model was verified and evaluated through ROC analysis, decision curve analysis (DCA), and prediction efficacy curve.

RESULTS

Multi-factorial logistic regression analysis revealed that history of smoking, family history of tumurs, Pepsinogen I (PG I), Gastrin 17 (G-17), Helicobacter pylori infection, D-dimer, and CXCL5 were independent risk factors in CAG patients. A nomogram for the diagnosis of CAG was constructed using R software. The ROC curve demonstrated that CXCL5 showed the best predictive efficacy as a single indicator, with an AUC of 0.897, a sensitivity of 0.789, and a specificity of 0.999. Furthermore, the nomogram exhibited an AUC of 0.992, a sensitivity of 0.958, and a specificity of 0.970. Calibration and DCA curves indicated that the predicted values of the nomogram were highly concordant with the observed values, thus demonstrating a high predictive value.

CONCLUSION

In this study, we found a correlation between serum CXCL5 level and CAG, and developed a prediction model to assist the clinical diagnosis of CAG.

Human blood metabolites and gastric cancer: a Mendelian randomization analysis

BACKGROUND

Gastric cancer (GC) remains one of the predominant malignant tumors within the digestive tract, yet its underlying biological mechanisms remain elusive. The primary objective of this study is to delineate the causal relationship between circulating metabolites and GC.

METHOD

The primary Mendelian randomization (MR) analysis was based on three large GWAS datasets. While the inverse variance weighted served as the primary analysis technique for investigating causal relationships, additional sensitivity analyses were facilitated through methods such as MR-PRESSO, the weighted median, and MR-Egger. Subsequently, replication, meta-analysis, and multivariable MR were executed using another GC GWAS.

RESULTS

The results of this study indicated significant associations between three metabolites 3-methyl-2-oxovalerate (OR 5.8, 95%CI: 1.53-22.05, p = 0.0099), piperine (OR 2.05, 95%CI: 1.13-3.7, p = 0.0175), Phe-Phe dipeptide (OR 0.16, 95%CI: 0.03-0.93, p = 0.0409) and GC.

CONCLUSION

The present study provides evidence supporting a causal relationship between these three circulating metabolites and GC risk. Elevated levels of 3-methyl-2-oxovalerate and piperine may increase the risk of GC, while Phe-Phe dipeptide may have a protective effect. By integrating genomics and metabolomics, we offer a novel perspective on the biological mechanisms underlying GC. Such insights have the potential to enhance strategies for the screening, prevention, and treatment of GC.

The role of neutrophil extracellular traps in Crohn's disease

Crohn's disease (CD) is an idiopathic and chronic inflammation of the gastrointestinal (GI) tract. The underlying pathogenesis of CD is multifaceted, with complex interactions between genetic predisposition, environmental triggers, and abnormalities within the immune system. Neutrophil extracellular traps (NETs) have gained significant attention as a novel component in the pathogenesis of CD. NETs are intricate structures fashioned from DNA, histones, and granule proteins, and are actively released by neutrophils to entangle and eliminate pathogenic microbes. This review article delves into the intricate role of NETs in the pathogenesis of CD. We examine how NETs may serve as a pivotal mechanism for the recruitment of immune cells to the site of inflammation. NETs are known to influence the function of epithelial cells, which line the GI tract, potentially contributing to the structural integrity and barrier dysfunction observed in CD. NETs stimulate inflammation, a hallmark of the disease, by releasing pro-inflammatory molecules and activating immune cells. We also investigate the promising therapeutic potential of targeting NETs in CD. By intercepting the formation or function of NETs, it may be possible to mitigate the chronic inflammation, reduce tissue damage, and alleviate the symptoms associated with CD. Strategies to inhibit NET formation, such as the use of DNase I and approaches to disrupt NET-mediated signaling pathways, are discussed in CD therapeutics. Understanding the detailed mechanisms of NETs is crucial for the development of targeted treatments that could potentially revolutionize the management of CD.

Education, intelligence, and 20 gastrointestinal disorders: A Mendelian randomization study

Previous observational studies have suggested that higher levels of education attainment and intelligence (IQ) are associated with better health outcomes in humans. However, the causal link between education attainment and IQ and their association with health outcomes remains unclear. This study aims to investigate the distinct impacts of intelligence and educational attainment on gastrointestinal symptoms. From the genome-wide association between educational attainment and the IQ study database, results were obtained from the FinnGen summary database. We used univariate and multivariate Mendelian randomization (MR) techniques to explore the relationship between exposures and outcomes. To assess the validity of inverse-variance-weighted-based results, we used several supplementary analytical techniques and performed sensitivity analysis. Our multivariate MR study confirmed the findings from univariable analyses and showed a genetically predicted causal association between educational attainment and 8 gastrointestinal disorders, including gastroesophageal reflux disease, chronic gastritis, gastroduodenal ulcer, cirrhosis, cholelithiasis, acute pancreatitis, chronic pancreatitis, and irritable bowel syndrome. Our univariate MR study found an association between IQ and 6 gastrointestinal conditions: gastroesophageal reflux disease, cirrhosis, cholelithiasis, acute pancreatitis, pancreatic malignancy, and irritable bowel syndrome. However, the connection was much weaker in multivariate MR analysis. Our study revealed causal relationships between gastrointestinal disorders and educational attainment. Educational attainment may mediate between intelligence and the impacts on the gastrointestinal system. However, further research is required to understand the underlying pathogenic processes completely.

Elucidating the causal relationship between 486 genetically predicted blood metabolites and the risk of gastric cancer: a comprehensive Mendelian randomization analysis

Background

Previous epidemiological studies have yielded inconclusive results regarding the causality between blood metabolites and the risk of gastric cancer (GC). To address this shortcoming, we conducted a two-sample Mendelian randomization (MR) study, combined with metabolomics techniques, to elucidate the causality between 486 genetically predicted blood metabolites and GC.

Methods

MR analysis and metabolomics techniques such as ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) and gas chromatography/tandem mass spectrometry (GC-MS/MS) technologies were employed to assess the causality of 486 genetically predicted blood metabolites on the risk of GC. The genome-wide association study (GWAS) summary data for 486 blood metabolites from 7,824 individuals. The GWAS summary data for GC (ebi-a-GCST90018849) were obtained from the IEU Open GWAS project, including 1,029 GC cases and 474,841 controls. Primary causality estimates were obtained using inverse variance weighting (IVW), supplemented with the weighted median, MR-Egger, weighted mode, and simple mode. In addition, we conducted sensitivity analyses (including Cochran's Q, MR-Egger intercept, MR-PRESSO, and leave-one-out tests),Steiger's test, linked disequilibrium score regression, and multivariate MR (MVMR) to improve the assessment of causality between GC and blood metabolite. Finally, we recruited a total of 11 patients diagnosed with gastric cancer from the First Affiliated Hospital of Air Force Military Medical University between September and October 2024. The control group comprised 11 healthy individuals. Serum samples were collected from both groups for the evaluation of blood-related metabolite expression levels using advanced techniques such as ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS/MS).

Results

The MVMR analysis revealed a significant association between genetically predicted elevated levels of tryptophan (odds ratio [OR] = 0.523, 95% confidence interval [CI] = 0.313-0.872, p = 0.013), nonadecanoate (19:0) (odds ratio [OR] = 0.460, 95% confidence interval [CI] = 0.225-0.943, p = 0.034), and erythritol (odds ratio [OR] = 0.672, 95% confidence interval [CI] = 0.468-0.930, p = 0.016) with a decreased risk of gastric cancer. Based on metabolomic techniques such as UPLC-MS/MS and GC-MS/MS analyses, it has been demonstrated that the expression levels of tryptophan, nonadecanoate (19:0), and erythritol are reduced in patients with gastric cancer. This finding aligns with the results obtained from our MR analysis and provides further confirmation regarding the protective role of tryptophan, nonadecanoate (19:0), and erythritol against gastric cancer.

Conclusions

These findings indicate that three blood metabolites are causally related to GC and provide new perspectives for combining genomics and metabolomics to study the mechanisms of metabolite-mediated GC development.

An atlas on risk factors for gastrointestinal cancers: A systematic review of Mendelian randomization studies

OBJECTIVE

Gastrointestinal cancers are one of the most frequent cancer types and seriously threaten human life and health. Recent studies attribute the occurrence of gastrointestinal cancers to both genetic and environmental factors, yet the intrinsic etiology remains unclear. Mendelian randomization is a powerful well-established statistical method that is based on genome-wide association study (GWAS) to evaluate the causal relationship between exposures and outcomes. In the present study, we aimed to conduct a systematic review of Mendelian randomization studies investigating any causal risk factors for gastrointestinal cancers.

METHODS

We systematically searched Mendelian randomization studies that addressed the associations of genetically predicted exposures with five main gastrointestinal cancers from September 2014 to March 2024, as well as testing the research quality and validity.

RESULTS

Our findings suggested robust and consistent causal effects of body mass index (BMI), basal metabolic rate, fatty acids, total cholesterol, total bilirubin, insulin like growth factor-1, eosinophil counts, interleukin 2, alcohol consumption, coffee consumption, apolipoprotein B on colorectal cancer risks, BMI, waist circumference, low-density lipoprotein (LDL), total testosterone, smoking on gastric cancer risks, BMI, fasting insulin, LDL, waist circumference, visceral adipose tissue (VAT), immune cells, type 2 diabetes mellitus (T2DM) on pancreatic cancer risks, waist circumference, smoking, T2DM on esophageal adenocarcinoma risks, and VAT, ferritin, transferrin, alcohol consumption, hepatitis B virus infection, rheumatoid arthritis on liver cancer risks, respectively.

CONCLUSION

Larger, well-designed Mendelian randomization studies are practical in determining the causal status of risk factors for diseases.

The relationship between smoking and rosacea: A Mendelian randomization study

BACKGROUND

Rosacea can be seen in many patients nowadays, and the related causes are complex. Despite a certain association between smoking and rosacea being reported by several studies, the actual causality has not been established for the possible bias and confounders.

METHODS

We used Mendelian randomization (MR) to evaluate a potential causal effect of smoking on rosacea risk. Statistics on smoking and rosacea were obtained from the FinnGen project and Neale Lab Consortium. The causal association was assessed by multiple methods including inverse variance weighted (IVW), MR Egger, weighted median, and weighted mode. Furthermore, sensitivity analyses were also conducted to address pleiotropy, along with the leave-one-out method.R version 4.2.3 was applied for the analyses.

RESULTS

The IVW estimation revealed that previous smoking has a deleterious effect on rosacea (odds ratio [OR] = 6.7729, 95% confidence interval [CI] = 1.5691-29.2356, p = 0.0104). By contrast, there was no statistically relationship between current smokers and rosacea (OR = 0.6180, 95% CI = 0.0605-6.3094, p = 0.6847). Results were similar in the analysis based on the weighted median method (previous smoking: OR = 8.6297, 95% CI = 1.0131-73.5071, p = 0.0486; current smoking: OR = 0.2896, 95% CI = 0.0106-7.9132, p = 0.4627). The stability of the causal effect estimates was supported by several sensitivity analyses and the leave-one-out method.

CONCLUSION

Our MR study found support forrosacea risk and previous smoking. Although no evidence was found to increase the risk of rosacea in current smokers, to prevent various diseases associated with smoking, the public should be encouraged to avoid smoking at the very beginning.

The role of 1400 plasma metabolites in gastric cancer: A bidirectional Mendelian randomization study and metabolic pathway analysis

While observational studies have illustrated correlations between plasma metabolites and gastric cancer (GC), the causal association between the 2 is still unclear. Our study aims to delineate the bidirectional relationship between plasma metabolites and GC and find potential metabolic pathways. We undertook a bidirectional 2-sample Mendelian randomization (MR) analysis to investigate the causal relationship, specificity, and direction of association between 1400 plasma metabolites and GC. The GWAS data for metabolites was obtained from a cohort of 8299 European individuals. And the GC's GWAS data was from FinnGen Consortium with 2384 European individuals, and the GWAS catalog with 1029 European ancestry cases for validation. Causal estimates were primarily calculated by the inverse-variance weighted (IVW) method. To ensure robustness, we performed comprehensive sensitivity analyses to assess heterogeneity and address concerns regarding horizontal pleiotropy. We validated the forward relationship between metabolites and GC from another database and implemented meta-analysis. Furthermore, we conducted metabolic enrichment and pathway analysis of these causal metabolites using MetaboAnalyst5.0/6.0 with the database of Kyoto Encyclopedia of Genes and Genomes. All statistical analysis was carried out using R software. Metabolites like 2s, 3R-dihydroxybutyrate, 4-acetamidobutanoate, ferulic acid 4-sulfate and methyl indole-3-acetate was proven positively linked with the development of GC. Asparagine, glucose to maltose ratio, glycohyocholate, Gulonate levels, linoleoyl ethanolamide and Spermidine to (N(1) + N(8))-acetylspermidine ratio was proven to be negatively associated with GC. Moreover, linoleic acid, histidine, glutamine, bilirubin, Succinate to proline ratio were found to be potentially linked to the development of GC. Furthermore, our analysis identified 18 significant metabolic pathways, including Arginine and proline metabolism (P < .009) and Valine, leucine, and isoleucine biosynthesis (P < .031). Our findings offer evidence supporting potential casual relations between multiple plasma metabolites and GC. These findings may offer great potential for future application of these biomarkers in GC screening and clinical prevention strategies.

Physical activity and constipation: A systematic review of cohort studies

Background

Constipation significantly impacts quality of life and is a common public health issue. For affected individuals, especially those who are inactive and experience constipation symptoms, it is recommended to engage in physical activity (PA) to improve their condition. However, the relationship between PA and improvement in constipation remains unclear. We performed this systematic review of cohort studies to evaluate this potential association.

Methods

We systematically searched the Embase, Cochrane Library, PubMed, and CINAHL databases for all cohort studies examining the relationship between PA and constipation from the inception of the databases up to 5 November 2023. We calculated the reported risk ratios (RRs) and 95% confidence intervals (CIs), conducted a random effects model, and performed a subgroup analysis based on factors such as gender, geographic region, and PA intensity to comprehensively explore the link between PA and constipation. Furthermore, we used the Newcastle-Ottawa Scale to evaluate the quality of the studies included in our analysis.

Results

The analysis included 13 studies with 119 426 participants and 63 713 cases. The results indicated that higher levels of PA were associated with a decreased risk of constipation compared with lower levels of PA (RR = 0.69; 95% CI = 0.88-0.83) and moderate levels of PA (RR = 0.87; 95% CI = 0.79-0.95). Furthermore, adherence to international PA guidelines was correlated with a significantly reduced risk of constipation (RR = 0.87; 95% CI = 0.81-0.93). Notably, the risk of constipation was lowered among Asian populations (RR = 0.67; 95% CI = 0.56-0.79) and Oceanian populations (RR = 0.72; 95% CI = 0.63-0.83) who engaged in regular PA. Moreover, when comparing the risk of constipation between men and women collectively, PA was associated with a 34% lower risk (RR = 0.66; 95% CI = 0.55-0.80).

Conclusions

The study findings indicated that moderate to high levels of PA significantly reduced the risk of constipation, showing a negative correlation between PA and constipation.

Registration

PROSPERO: CRD42023479653.

Molecular mechanisms underlying roles of long non-coding RNA small nucleolar RNA host gene 16 in digestive system cancers

This editorial reviews the molecular mechanisms underlying the roles of the long non-coding RNA (lncRNA) small nucleolar RNA host gene 16 (SNHG16) in digestive system cancers based on two recent studies on lncRNAs in digestive system tumors. The first study, by Zhao et al, explored how hBD-1 affects colon cancer, via the lncRNA TCONS_00014506, by inhibiting mTOR and promoting autophagy. The second one, by Li et al, identified the lncRNA prion protein testis specific (PRNT) as a factor in oxaliplatin resistance by sponging ZNF184 to regulate HIPK2 and influence colorectal cancer progression and chemoresistance, suggesting PRNT as a potential therapeutic target for colorectal cancer. Both of these two articles discuss the mechanisms by which lncRNAs contribute to the development and progression of digestive system cancers. As a recent research hotspot, SNHG16 is a typical lncRNA that has been extensively studied for its association with digestive system cancers. The prevailing hypothesis is that SNHG16 participates in the development and progression of digestive system tumors by acting as a competing endogenous RNA, interacting with other proteins, regulating various genes, and affecting downstream target molecules. This review systematically examines the recently reported biological functions, related molecular mechanisms, and potential clinical significance of SNHG16 in various digestive system cancers, and explores the relationship between SNHG16 and digestive system cancers. The findings suggest that SNHG16 may serve as a potential biomarker and therapeutic target for human digestive system cancers.

Explore key genes of Crohn's disease based on glycerophospholipid metabolism: A comprehensive analysis Utilizing Mendelian Randomization, Multi-Omics integration, Machine Learning, and SHAP methodology

BACKGROUND AND AIMS

Crohn's disease (CD) is a chronic, complex inflammatory condition with increasing incidence and prevalence worldwide. However, the causes of CD remain incompletely understood. We identified CD-related metabolites, inflammatory factors, and key genes by Mendelian randomization (MR), multi-omics integration, machine learning (ML), and SHAP.

METHODS

We first performed a mediation MR analysis on 1400 serum metabolites, 91 inflammatory factors, and CD. We found that certain phospholipids are causally related to CD. In the scRNA-seq data, monocytes were categorized into high and low metabolism groups based on their glycerophospholipid metabolism scores. The differentially expressed genes of these two groups of cells were extracted, and transcription factor prediction, cell communication analysis, and GSEA analysis were performed. After further screening of differentially expressed genes (FDR<0.05, log2FC>1), least absolute shrinkage and selection operator (LASSO) regression was performed to obtain hub genes. Models for hub genes were built using the Catboost, XGboost, and NGboost methods. Further, we used the SHAP method to interpret the models and obtain the gene with the highest contribution to each model. Finally, qRT-PCR was used to verify the expression of these genes in the peripheral blood mononuclear cells (PBMC) of CD patients and healthy subjects.

RESULT

MR results showed 1-palmitoyl-2-stearoyl-gpc (16:0/18:0) levels, 1-stearoyl-2-arachidonoyl-GPI (18:0/20:4) levels, 1-arachidonoyl-gpc (20:4n6) levels, 1-palmitoyl-2-arachidonoyl-gpc (16:0/20:4n6) levels, and 1-arachidonoyl-GPE (20:4n6) levels were significantly associated with CD risk reduction (FDR<0.05), with CXCL9 acting as a mediation between these phospholipids and CD. The analysis identified 19 hub genes, with Catboost, XGboost, and NGboost achieving AUC of 0.91, 0.88, and 0.85, respectively. The SHAP methodology obtained the three genes with the highest model contribution: G0S2, S100A8, and PLAUR. The qRT-PCR results showed that the expression levels of S100A8 (p = 0.0003), G0S2 (p < 0.0001), and PLAUR (p = 0.0141) in the PBMC of CD patients were higher than healthy subjects.

CONCLUSION

MR findings suggest that certain phospholipids may lower CD risk. G0S2, S100A8, and PLAUR may be potential pathogenic genes in CD. These phospholipids and genes could serve as novel diagnostic and therapeutic targets for CD.

Global and regional burden of pancreatitis: epidemiological trends, risk factors, and projections to 2050 from the global burden of disease study 2021

BACKGROUND

Pancreatitis is a significant global health concern with rising incidence, complex management, and substantial mortality. This study aimed to assess global and regional trends in pancreatitis from 1990 to 2021 and project future trends to 2050 using data from the Global Burden of Disease (GBD) Study 2021.

METHODS

We analyzed GBD 2021 data to evaluate age-standardized incidence (ASIR), mortality (ASMR), and disability-adjusted life years (DALYs) rates of pancreatitis. Regional trends, gender disparities, and correlations with the Socio-demographic Index (SDI) were examined. Key risk factors, including alcohol consumption, smoking, and metabolic disorders such as hyperlipidemia, were extracted and evaluated. A Bayesian age-period-cohort model (BAPC) was used for future projections.

RESULTS

From 1990 to 2021, global pancreatitis cases increased from 1.73 million to 2.75 million, representing a rise of 59%. Despite this, ASIR decreased slightly from 37.62 to 32.81 per 100,000, a 12.8% reduction. Deaths rose from 68,490 to 122,416, an increase of 78.7%, while ASMR decreased from 1.69 to 1.45 per 100,000, a reduction of 14.2%. DALYs increased from 2.58 million to 4.10 million (59%). Significant regional variations were found, with Eastern Europe showing the highest ASIR, ASMR, and DALY rates. Projections indicate continued declines in ASIR, ASMR, and DALYs through 2050.

CONCLUSIONS

While global age-standardized rates of pancreatitis have declined, significant regional and socioeconomic disparities persist. Targeted prevention efforts, particularly in high-burden areas like Eastern Europe, and addressing modifiable risk factors such as alcohol use are crucial for reducing the future burden of pancreatitis.

Alcohol consumption and its association with cancer, cardiovascular, liver and brain diseases: a systematic review of Mendelian randomization studies

Background

The health effects of alcohol consumption, particularly regarding potential protective benefits of light to moderate intake compared to abstinence, remain a subject of ongoing debate. However, epidemiological studies face limitations due to imprecise exposure measurements and the potential for bias through residual confounding and reverse causation. To address these limitations, we conducted a systematic review of Mendelian Randomization (MR) studies examining the causal relationship between alcohol consumption and cancers, cardiovascular, liver, and neurological diseases.

Methodology

We searched PubMed, ScienceDirect and Embase and Europe PMC up to 05/2024 for MR studies investigating the association of genetically predicted alcohol consumption with cancers, cardiovascular, liver and neurological diseases. We assessed methodological quality based on key elements of the MR design a genetic association studies tool.

Results

We included 70 MR studies that matched our inclusion criteria. Our review showed a significant association of alcohol consumption with multiple cancers such as oral and oropharyngeal, esophageal, colorectal cancers, hepatocellular carcinoma and cutaneous melanoma. While the available studies did not consistently confirm the adverse or protective effects of alcohol on other cancers, such as lung cancer, as suggested by observational studies. Additionally, MR studies confirmed a likely causal effect of alcohol on the risk of hypertension, atrial fibrillation, myocardial infraction and vessels disease. However, there was no evidence to support the protective effects of light to moderate alcohol consumption on cognitive function, Alzheimer's disease, and amyotrophic lateral sclerosis, as reported in observational studies while our review revealed an increased risk of epilepsy and multiple sclerosis. The available studies provided limited results on the link between alcohol consumption and liver disease.

Conclusions

Despite the valuable insights into the causal relationship between alcohol consumption and various health outcomes that MR studies provided, it is worth noting that the inconsistent ability of genetic instrumental variables to distinguish between abstainers, light and moderate drinkers makes it difficult to differentiate between U or J-shaped vs. linear relationships between exposure and outcome. Additional research is necessary to establish formal quality assessment tools for MR studies and to conduct more studies in diverse populations, including non-European ancestries.

Systematic Review Registration

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021246154, Identifier: PROSPERO (CRD42021246154).

A Predictive Nomogram for the Occurrence of Gastroesophageal Reflux Disease After Sleeve Gastrectomy: A Study Based on Preoperative HERM

Purpose

Gastroesophageal reflux disease (GERD) is a common complication after laparoscopic sleeve gastrectomy (LSG); This study aimed to construct a model that can predict the incidence of GERD after LSG by exploring the correlation between the results of high-resolution esophageal manometry (HREM) and the incidence of GERD after LSG.

Patients and Methods

We collected the clinical data of patients who had undergone HREM before bariatric surgery from September 2013 to September 2019 at the bariatric center of our hospital. The Gerd-Q scores during the postoperative follow-up were collected to determine the incidence of GERD. A logistic regression analysis was performed to explore the correlation of the HREM results and general clinical data with the incidence of GERD after LSG.

Results

The percentage of synchronous contractions, lower esophageal sphincter (LES) resting pressure, and history of smoking were correlated with the development of GERD after LSG, with the history of smoking and percentage of synchronous contractions as risk factors and LES resting pressure as a protective factor. The training set showed an area under the ROC curve (AUC) of the nomogram model of 0.847. The validation set showed an AUC of 0.761. The decision and clinical impact curves showed a high clinical value for the prediction model.

Conclusion

The HREM results correlated with the development of GERD after LSG, with the percentage of synchronous contractions and LES resting pressure showing predictive value. Combined with the history of smoking, the predictive model showed a high confidence and clinical value.

Therapeutic targets for lung cancer: genome-wide Mendelian randomization and colocalization analyses

Background

Lung cancer, categorized into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), remains a significant global health challenge. The development of drug resistance and the heterogeneity of the disease necessitate the identification of novel therapeutic targets to improve patient outcomes.

Methods

We conducted a genome-wide Mendelian randomization (MR) and colocalization analysis using a comprehensive dataset of 4,302 druggable genes and cis-expressed quantitative trait loci (cis-eQTLs) from 31,884 blood samples. The study integrated genomic analysis with eQTL data to identify key genes associated with lung cancer risk.

Results

The analysis revealed five actionable therapeutic targets for NSCLC, including LTB4R, LTBP4, MPI, PSMA4, and TCN2. Notably, PSMA4 demonstrated a strong association with both NSCLC and SCLC risks, with odds ratios of 3.168 and 3.183, respectively. Colocalization analysis indicated a shared genetic etiology between these gene expressions and lung cancer risk.

Conclusion

Our findings contribute to precision medicine by identifying druggable targets that may be exploited for subtype-specific lung cancer therapies.

Therapeutic targets for gastrointestinal diseases: proteome-wide Mendelian randomization and colocalization analyses

PURPOSE

This study was aimed to identify serum proteins linked with gastrointestinal diseases by proteome-wide Mendelian randomization analysis.

METHODS

We determined the casual relationship between 732 kinds of circulating proteins and the 24 kinds of gastrointestinal diseases via Mendelian randomization analysis.

RESULTS

Four circulating proteins (FCGR3B, IL-12B, MAPKAPK2, and IL-23R) were associated with the occurrence of ulcerative colitis (UC), and IL23R was also correlated with risk of Crohn's disease (CD). Genetically predicted levels of IL23R were strongly correlated with the risk of UC and CD based on the high supporting evidence of colocalization analysis. Five circulating proteins (NOV, EFEMP1, ADGRE2, LCT, and SEMA3G) were associated with the risk of diverticulosis disease. With high supporting evidence of colocalization, genetically predicted levels of NOV and SEMA3G were inversely correlated with the risk of diverticulosis disease. Five circulating proteins (FUT3, FUT5, CRHBP, SULT2A1, and QPCTL) were associated with the occurrence of cholelithiasis. With high supporting evidence of colocalization, genetically predicted levels of FUT3 and CRHBP were inversely correlated with the risk of cholelithiasis.

CONCLUSIONS

The proteome-wide Mendelian randomization investigation identified several circulating proteins associated with the risk of UC, CD, diverticular disease and cholelithiasis, which reinforced the understanding of molecular pathogenesis and design of therapeutic targets.

A Mendelian analysis of the causality between inflammatory cytokines and digestive tract cancers

PURPOSE

In this study, we performed a two-sample Mendelian randomization (MR) analysis to assess the causality between inflammatory cytokines and the risk of digestive tract cancers (DTCs). Furthermore, we conducted a molecular docking study to predict the therapeutic mechanisms of traditional Chinese medicine (TCM) compounds in the treatment of DTCs.

METHODS

In our MR analysis, genetic variations associated with eight types of DTCs were utilized, which were sourced from a large publicly available genome-wide association study dataset (7929 cases and 1 742 407 controls of European ancestry) and inflammatory cytokines data from a genome-wide association study summary of 8293 European participants. Inverse-variance weighted method, MR-Egger, and weighted median were performed to analyze and strengthen the final results. We investigated the effects of 41 inflammatory molecules on 8 types of DTCs. Subsequently, the effect of DTCs on positive inflammatory factors was analyzed by means of inverse MR. Molecular docking was exploited to predict therapeutic targets with TCM compounds.

RESULTS

Interleukin-7, interleukin-16, macrophage colony-stimulating factor, monokine induced by interferon-gamma, and vascular endothelial growth factor may be significantly associated with various types of DTCs. Five TCM compounds (baicalin, berberine, curcumin, emodin, and salidroside) demonstrated better binding energies to both interleukin-7 and vascular endothelial growth factor than carboplatin.

CONCLUSION

This study provides strong evidence to support the potential causality of some inflammatory cytokines on DTCs and indicates the potential molecular mechanism of TCM compounds in the treatment of DTCs. Key message What is already known on this topic  The increasing evidence indicates that inflammatory cytokines are implicated in the pathogenesis of digestive tract cancers (DTCs). Nevertheless, the causal relationship between inflammatory cytokines and DTCs remains indistinct. Additionally, certain traditional Chinese medicine compounds have been demonstrated to treat DTCs by influencing inflammatory factors, yet their underlying potential mechanisms remain ambiguous. What this study adds  In this study, Mendelian randomization analysis was performed for the first time regarding the causality between human inflammatory cytokines and eight types of DTCs, which revealed that inflammatory factors may play different roles in different types of DTCs. Moreover, molecular docking of key inflammatory factors was implemented, indicating the targets for drug actions. How this study might affect research, practice, or policy  This research has the potential to reveal the causality between 41 inflammatory factors and 8 DTCs, offering novel perspectives for the prevention and management strategies of DTCs. Additionally, it indicates the targets for the actions of traditional Chinese medicine on the key inflammatory factors of these cancers.

Investigating the relationship between blood metabolites and diabetic retinopathy using two-sample mendelian randomization and in vivo validation

We addressed fundamental questions about the influence of metabolites on the development of Diabetic retinopathy (DR), and explored the related pathological mechanism. Genome-wide association study (GWAS) database data for metabolites and DR were used to perform Mendelian randomization (MR) studies. The inverse variance weighting (IVW) was chosen as the primary analysis method. Sensitivity analysis was conducted using MR-PRESSO, leave-one-out and Cochran's Q test. Confounding factors were eliminated to ensure robustness. We also conducted metabolic pathway analysis. In vivo experimental validation was conducted using Sprague Dawley rats. The serum metabolites of the DR group rats and normal group rats were examined to evaluate the MR results. The screen identified eighteen metabolites associated with DR risk, twelve of which were known components. Seven metabolites were positively correlated with DR risk, while five could reduce it. Eight metabolites associated with proliferative DR (PDR) risk were identified, four of which are known components. Three of these were positively associated with PDR risk and one metabolite reduced PDR risk. Additionally, two possible metabolic pathways involved in the biological mechanism of DR were identified. The ELISA results showed that the serum levels of isoleucine and 4-HPA were significantly increased in DR rats, while the level of inosine was decreased. This study offers novel insights into the biological mechanisms underlying DR. Metabolites that are causally linked to DR may serve as promising biomarkers and therapeutic targets.

Causal Relationship Between Gastroesophageal Reflux Disease and the Risk of Chronic Rhinosinusitis: Insights from Multivariable and Mediation Mendelian Randomization Analysis

Background: Previous studies have shown an association between chronic rhinosinusitis (CRS) and gastroesophageal reflux disease (GERD). However, the findings of these studies are controversial, and evaluating this association could help in the treatment of CRS. Thus, we aimed to clarify the relationship between GERD and CRS. Methods: We conducted a Mendelian randomization (MR) study. Pooled data on CRS, GERD, and their associated risk factors were extracted from large genome-wide association studies. Independent single-nucleotide polymorphisms were rigorously screened as instrumental variables. Causal associations between GERD and CRS were assessed, and mediation analyses were performed using multivariate and 2-step MR. Asthma served as a mediator because of its association with both CRS and GERD. Sensitivity tests were also performed. Results: MR analysis showed that genetically predicted GERD was associated with an increased risk of CRS (P < .001). Multivariate MR analysis showed that the effect of GERD on CRS was relatively independent. Mediation analysis showed that asthma mediated the association with a mediation effect of 21.07% (95% CI, 2.70%-40.18%). Sensitivity analyses did not reveal any significant effects of pleiotropy and heterogeneity. Conclusions: We found a causal relationship between genetically predicted GERD and an increase in the risk of CRS. As a mediator, asthma contributed to the effect of GERD on CRS. This study provides high-quality causal evidence for the prevention of CRS.

Identifying a perforated prepyloric ulcer during laparoscopy in a patient presumed to have cholecystitis

Abdominal pain in patients with significant alcohol use and smoking history presents diagnostic challenges due to overlapping clinical features of complications like acute cholecystitis and peptic ulcers. The unreliable physical examinations of intoxicated patients often complicate accurate diagnosis. We present a case of a 56-year-old male with a history of alcoholism and smoking, who presented to the emergency department with nonspecific abdominal pain. Initial imaging suggested cholecystitis, but due to the patient's intoxication, his physical examination was unreliable. During a laparoscopic cholecystectomy, a perforated prepyloric ulcer was unexpectedly discovered, sealed by the gallbladder. This case highlights the limitations of relying solely on imaging for diagnosing abdominal conditions in intoxicated patients. The intraoperative discovery of the perforated ulcer necessitated a shift in the surgical approach, emphasizing the need for flexibility in surgical planning and a high index of suspicion for other abdominal pathologies in patients with significant lifestyle risks. The successful management of this patient through adaptive surgical techniques and comprehensive postoperative care, including Helicobacter pylori eradication therapy, underscores the importance of maintaining a broad differential diagnosis and readiness to adapt surgical plans. This approach is essential for managing complex cases effectively, ensuring that both the immediate surgical issues and underlying causes are addressed to optimize recovery and prevent recurrence.

Association of periodontitis with gastrointestinal tract disorders: A bidirectional Mendelian randomization study

BACKGROUND

The bidirectional link of periodontitis (PD) and gastrointestinal tract (GIT) disorders has been investigated in previous epidemiological studies; however, the conclusions still remain controversial. The aim of this study was to comprehensively explore the bidirectional causal effect between PD and various GIT diseases.

METHODS

Based on summary-level data of genome-wide association studies (GWASs), a two-sample bidirectional Mendelian randomization (MR) study was undertaken. Single-nucleotide polymorphisms (SNPs) associated with PD or GIT disorders (chronic gastritis [CG], gastric ulcer [GU], duodenal ulcer [DU], gastroesophageal reflux disease [GERD], irritable bowel syndrome [IBS], and diverticular disease of the intestine [DI]) in GWASs were applied as exposure. The primary method employed was the inverse-variance weighted (IVW) method, and several sensitivity analyses were performed to investigate potential pleiotropy.

RESULTS

With regard to the investigation of the causality between PD and GIT disorders, the IVW method revealed that there is a causal impact of PD on GU (odds ratio [OR] 1.088; 95% confidence interval [CI], 1.036-1.141; adjusted p = 0.004) and DI (OR 0.938; 95% CI, 0.911-0.965; adjusted p = 0.000). However, no significant genetic liability was observed for the causal effect of PD on CG, DU, GERD, and IBS. Furthermore, the primary analysis did not demonstrate a causal effect of GIT disorders on PD.

CONCLUSION

This MR study suggests that PD may be associated with an increased risk of GU and a reduced risk of DI, with possibly limited clinical relevance. Further studies are needed to support the conclusions of this MR study.

Assessing the causal relationship between obesity and hypothyroidism using Mendelian randomization

To explore the causal relationship between obesity and hypothyroidism and identify risk factors and the predictive value of subclinical hypothyroidism (SCH) in obese patients using Mendelian randomization, this study employed five Mendelian randomization methods (MR Egger, Weighted Median, Inverse Variance Weighted, Simple Mode, and Weighted Mode) to analyze clinical data from 308 obese patients at the People's Hospital of Xinjiang Uygur Autonomous Region, from January 2015 to June 2023. Patients were divided based on thyroid function tests into normal (n = 173) and SCH groups (n = 56). Comparative analyses, along with univariate and multivariate logistic regression, were conducted to identify risk factors for SCH in obese patients. A significant association between obesity and hypothyroidism was established, especially highlighted by the inverse variance weighted method. SCH patients showed higher ages, thyroid-stimulating hormone levels, and thyroid autoantibody positivity rates, with lower T4 and FT4 levels. Age, FT4, thyroid autoantibodies, TPO-Ab, and Tg-Ab were confirmed as risk factors. The predictive value of FT4 levels for SCH in obesity was significant, with an Area Under the Curve (AUC) of 0.632. The study supports a potential causal link between obesity and hypothyroidism, identifying specific risk factors for SCH in obese patients. FT4 level stands out as an independent predictive factor, suggesting its utility in early diagnosis and preventive strategies for SCH.

Artificial sweetener and respiratory system cancer: A Mendelian randomization analysis

BACKGROUND & AIMS

The association between artificial sweeteners and various cancers has been investigated, but their relationship with respiratory system cancers remains uncertain. To address this knowledge gap, we conducted a comprehensive Mendelian Randomization (MR) analysis.

METHODS

We looked for SNPs associated with artificial sweetener intake and respiratory system cancers from the IEU OpenGWAS project, as well as SNPs related to sweet taste in artificial sweeteners from Hwang et al.'s study. Rigorous quality control procedures were implemented to select instrumental Single Nucleotide Polymorphisms that were closely linked to artificial sweetener intake. To ensure the reliability of our findings, we employed five different analytical methods, with the inverse variance weighting method being the primary approach. Additionally, we thoroughly assessed heterogeneity, pleiotropy, and sensitivity. Finally, we conducted Multivariable Mendelian Randomization (MVMR) to validate our results.

RESULTS

Intake of artificial sweetener added to cereal showed a positive association with malignant neoplasm of the lip, oral cavity, and pharynx (OR: 1027.54; 95% CI: 4.8-219994.46; P = 0.011), and the result was also confirmed by the MVMR analysis. In addition, better perceived intensity of aspartame was negatively associated with cancers in these regions (OR: 0.49; 95% CI: 0.28-0.88; P = 0.016). Intake of artificial sweetener added to coffee or tea was not related with respiratory system cancer.

CONCLUSIONS

Our research offers evidence that the consumption of artificial sweeteners in cereals could increase the risk of cancers in the lip, oral cavity, and pharynx. Additionally, a greater sensitivity to the taste of aspartame may lower this risk.

Causal relationship between circulating immune cells and gastric cancer: a bidirectional Mendelian randomization analysis using UK Biobank and FinnGen datasets

Background

The role of immune cells in cancer pathogenesis remains controversial due to conflicting reports, potentially arising from various confounding factors. Emerging evidence suggests that cancer can also influence immune cell populations and functions, making it challenging to investigate their causal relationship. Traditional observational studies often fail to eliminate all confounding factors and are prone to reverse causality. Therefore, we employ Mendelian randomization (MR) to determine the causal relationship between immune cells and cancer, as this method can identify causal relationships independent of confounding factors and avoid reverse causality.

Methods

Genome-wide association study (GWAS) summary statistics on immune traits, encompassing 310 immune cell phenotypes, were obtained from 3,757 European individuals, with peripheral blood immune cells tested using flow cytometry. GWAS summary statistics for gastric cancer were derived from 476,116 European individuals across two large-scale biobanks: the UK Biobank and FinnGen. Gastric cancer was identified by the International Classification of Diseases, 9th Revision (ICD-9), and 10th Revision (ICD-10) codes. Significant single nucleotide polymorphisms (SNPs) for immune traits were extracted at a threshold of P<1×10-5, while a threshold of P<5×10-8 was used for gastric cancer GWAS data. Linkage imbalance-based clumping was performed to obtain independent SNPs, and those with F<10 were excluded to mitigate weak instrument bias. Phenoscanner V2 was used to exclude SNPs directly associated with potential confounders or outcomes. Two-sample MR was conducted using five MR methods, with inverse-variance-weighted (IVW) as the primary analysis method. A false discovery rate (FDR) correction was used to reduce the likelihood of type 1 errors. In addition, we conducted MR-Egger intercept tests and Cochran's Q tests.

Results

The numbers of CD4-CD8- T cells and IgD-CD27- B cells were positively correlated with the development of gastric cancer, with odds ratios (ORs) of 1.15 [95% confidence interval (CI), 1.07-1.24; P<0.001; PFDR=0.041; IVW method] and 1.07 (95% CI, 1.03-1.11; P=0.001; PFDR=0.187; IVW method), respectively. However, the percentage of IgD+CD24- B cells in lymphocytes were negatively associated with the development of gastric cancer (OR =0.90; 95% CI, 0.84-0.96; P=0.002; PFDR=0.187; IVW method). MR analysis of the above three immune cell phenotypes showed no significant heterogeneity or horizontal pleiotropy. In the reverse MR analysis, gastric cancer was not causally associated with any of the immune cell phenotypes.

Conclusions

Circulating CD4-CD8- T cells and IgD-CD27- B cells are positively correlated with the development of gastric cancer, while the percentage of IgD+CD24- B cells in lymphocytes are negatively correlated. These findings provide insight into the relationship between immune cells and gastric cancer pathogenesis and may serve as a basis for the development of immunotherapies for gastric cancer.

Causal Relationship Between Mood Swing and Gynecological Disorders: A Mendelian Randomization Study

Background

Gynecological disorders are a wide range of health problems affecting the female reproductive system, which poses substantial health challenges worldwide. Increasing number of observational studies have associated mood instability to common female diseases, but the underlying causal relationship remains unclear. In this work, Mendelian randomization (MR) analysis was applied to explore the genetically predicted causal relationship of mood swings and several prevalent gynecological disorders.

Methods

Instrumental variables (IVs) of mood swings were selected from UK Biobank (UKB), with 204,412 cases and 247,207 controls being incorporated. The genetic variants for female disorders were obtained from genome-wide association studies (GWASs) and FinnGen consortium. To avoid biases caused by racial difference, only European population was included here. Five strong analytical methodologies were used to increase the validity of the results, the most substantial of which was the inverse variance weighting (IVW) method. Pleiotropy, sensitivity, and heterogeneity were assessed to strengthen the findings.

Results

We found mood swings was significantly positively associated with risk of endometrial cancer (OR= 2.60 [95% CI= 1.36, 4.95], P= 0.0037), cervical cancer (OR= 1.01[95% CI= 1.00,1.02], P= 0.0213) and endometriosis (OR= 2.58 [95% CI= 1.18, 5.60], P= 0.0170) by IVW method. However, there was no causal relationship between mood swing and ovarian cancer. No pleiotropy and heterogeneity existed and sensitivity tests were passed.

Conclusion

This study reveals that mood swing may serve as a genetically predicted causal risk factor for endometrial cancer, cervical cancer, and endometriosis in the European population, while no such association was observed for ovarian cancer. These findings make up for observational research's inherent limitations and may improve patient outcomes in the field of gynecological health. However, the study's focus on European populations may limit the applicability of these results globally.

Associations of weight control related behaviors with current cigarette smoking among Chinese adolescents: Results from an ongoing school-based survey in Zhejiang province

INTRODUCTION

Previous studies have suggested that adolescents may smoke cigarettes to control weight, but relevant research is scarce in Chinese youth. This study was conducted to examine the associations of weight control related behaviors with cigarette smoking in Chinese students.

METHODS

This was a secondary analysis of data for 24835 middle and high school students drawn from the 2022 Zhejiang Youth Risk Behavior Survey of China which collected self-reported information of cigarette smoking, weight control strategies and other health-related behaviors. Multivariable logistic regression models were used to estimate the adjusted odds ratios (AORs) with 95% confidence intervals (CIs) for the study associations.

RESULTS

Overall, there were 998 (4.02%) current cigarette smokers in this wave of the Zhejiang YRBS (2022). Neither trying to control weight nor healthy weight control behavior of exercising was associated with current cigarette smoking (AOR=1.15; 95% CI: 0.97-1.37 and AOR=1.01; 95% CI: 0.85-1.20, respectively). Meanwhile, unhealthy weight control behaviors of taking laxatives (AOR=1.52; 95% CI: 1.03-2.26), taking diet pills (AOR=1.82; 95% CI: 1.26-2.62), dieting (AOR=1.24; 95% CI: 1.04-1.49), and fasting (AOR=1.81; 95% CI: 1.40-2.34) were significantly associated with increased odds of current cigarette smoking.

CONCLUSIONS

Screening and developing interventions for unhealthy weight control behaviors should be considered as part of smoking prevention programs among adolescents.

Addressing the credibility crisis in Mendelian randomization

BACKGROUND

Genome-wide association studies have enabled Mendelian randomization analyses to be performed at an industrial scale. Two-sample summary data Mendelian randomization analyses can be performed using publicly available data by anyone who has access to the internet. While this has led to many insightful papers, it has also fuelled an explosion of poor-quality Mendelian randomization publications, which threatens to undermine the credibility of the whole approach.

FINDINGS

We detail five pitfalls in conducting a reliable Mendelian randomization investigation: (1) inappropriate research question, (2) inappropriate choice of variants as instruments, (3) insufficient interrogation of findings, (4) inappropriate interpretation of findings, and (5) lack of engagement with previous work. We have provided a brief checklist of key points to consider when performing a Mendelian randomization investigation; this does not replace previous guidance, but highlights critical analysis choices. Journal editors should be able to identify many low-quality submissions and reject papers without requiring peer review. Peer reviewers should focus initially on key indicators of validity; if a paper does not satisfy these, then the paper may be meaningless even if it is technically flawless.

CONCLUSIONS

Performing an informative Mendelian randomization investigation requires critical thought and collaboration between different specialties and fields of research.

Genetic estimation of causalities between educational attainment with common digestive tract diseases and the mediating pathways

BACKGROUND

The association between education, intelligence, and cognition with digestive tract diseases has been established. However, the specific contribution of each factor in the pathogenesis of these diseases are still uncertain.

METHOD

This study employed multivariable Mendelian randomization (MR) to assess the independent effects of education, intelligence, and cognition on gastrointestinal conditions in the FinnGen and UK Biobank European-ancestry populations. A two-step MR approach was employed to assess the mediating effects of the association.

RESULTS

Meta-analysis of MR estimates from FinnGen and UK Biobank showed that 1- SD (4.2 years) higher education was causally associated with lower risks of gastroesophageal reflux (OR: 0.58; 95% CI: 0.50, 0.66), peptic ulcer (OR: 0.57; 95% CI: 0.47, 0.69), irritable bowel syndrome (OR: 0.70; 95% CI: 0.56, 0.87), diverticular disease (OR: 0.69; 95% CI: 0.61, 0.78), cholelithiasis (OR: 0.68; 95% CI: 0.59, 0.79) and acute pancreatitis (OR: 0.54; 95% CI: 0.41, 0.72), independently of intelligence and cognition. These causal associations were mediating by body mass index (3.7-22.3%), waist-to-hip ratio (8.3-11.9%), body fat percentage (4.1-39.8%), fasting insulin (1.4-5.5%) and major depression (6.0-12.4%).

CONCLUSION

Our findings demonstrate a causal and independent association between education and six common digestive tract diseases. Additionally, our study highlights five mediators as crucial targets for preventing digestive tract diseases associated with lower education levels.

Causal relationship between dietary intake and IgA nephropathy: a Mendelian randomization study

Objective

Previous studies have reported that dietary intake is associated with immunoglobulin A nephropathy (IgAN). However, the causal relationship remains unknown. Based on publicly available genome-wide association study (GWAS) data, we conducted a two-sample Mendelian randomization (MR) analysis to assess the causal association between 26 dietary exposures and IgAN.

Methods

Five methods, including inverse variance weighting (IVW), MR-Egger regression, weighted median, simple mode, and weighted mode, were applied in the MR analysis. To identify the presence of horizontal pleiotropy, we used the MR-Egger intercept test and MR pleiotropy residual sum and outlier (MR-PRESSO) global test. Cochran's Q statistics were used to assess instrument heterogeneity. We conducted sensitivity analysis using the leave-one-out method.

Results

Finally, the results indicated alcohol intake frequency (odds ratio [OR] (95% confidence interval [CI]) = 1.267 (1.100-1.460), p = 0.0010295) was a risk factor of IgAN, while cheese intake (OR (95% CI) = 0.626 (0.492-0.798), p = 0.0001559), cereal intake (OR (95% CI) = 0.652 (0.439-0.967), p = 0.0334126), and sushi intake (OR (95% CI) = 0.145 (0.021-0.997), p = 0.0497) were protective factors of IgAN. No causal relationship was found between IgAN and the rest of the dietary exposures.

Conclusion

Our study provided genetic evidence that alcohol intake frequency was associated with an increased risk of IgAN, while cheese, cereal, and sushi intake were associated with a decreased risk of IgAN. Further investigation is required to confirm these results.

Health condition and socioeconomic status mediate the causal effect of reproductive traits on nonalcoholic fatty liver disease: evidence from Mendelian randomization study

Background

Observational data posits a correlation between reproductive traits and nonalcoholic fatty liver disease (NAFLD), but their causal inference is still unclear. This investigation seeks to elucidate the causal influence of reproductive traits on NAFLD and determine the intervening role of health condition and socioeconomic status in these connections.

Methods

Utilizing a Mendelian Randomization (MR) approach, this research leveraged a comprehensive dataset from the Genome-wide Association Study (GWAS) database. The study incorporated body mass index, major depression, educational level, household income and Townsend deprivation index as intermediary variables. Initially, a bidirectional two-sample MR study was conducted to explore the genetic associations between reproductive traits and NAFLD. Then, two-step MR analyses were implemented to quantify the extent of mediation by these indicators. The weighted inverse variance method was the primary analytical approach, complemented by several sensitivity analyses to affirm the robustness of the MR assumptions. Finally, these findings were validated in the FinnGen research.

Results

The bidirectional MR analysis indicated that earlier reproductive traits (age at menarche, age at first sexual intercourse, and age at first birth) were associated with an elevated risk of NAFLD, absent any evidence of the reverse relationship. Body mass index accounted for 35.64% of the association between premature menarche and NAFLD. Additionally, body mass index, major depression, educational level and household income mediated 41.65%, 14.35%, 37.88%, and 18.59% of the connection between early sexual intercourse and NAFLD, respectively. Similarly, these same variables elucidated 36.36%, 15.58%, 41.56%, and 22.73% of the correlation between younger age at first birth and NAFLD.

Conclusion

Our study elucidated the causal relationships between reproductive traits and NAFLD. Potential underlying mechanisms may involve factors such as body mass index, major depression, educational attainment and household income.

Long-term outcomes of smoker and drinker with oesophageal squamous cell carcinoma after oesophagectomy: a large-scale propensity score matching analysis

BACKGROUND

Oesophageal squamous cell carcinoma (OSCC) poses a considerable health burden, particularly in regions such as East Asia. This study aims to investigate the long-term outcomes of OSCC patients who are smokers and drinkers.

MATERIALS AND METHODS

In this retrospective analysis, data from Sichuan Cancer Hospital and Institute Esophageal Cancer Case Management Database between January 2010 and December 2017 were examined. Patients were categorised into different groups based on their smoking and alcohol consumption history: None, Smoker, Non-Smoker, Smoke-Only, Drinker, Non-Drinker, Drinker-Only, and Both. Survival outcomes were compared between the groups using Kaplan-Meier analysis and propensity score matching (PSM). The primary outcome was overall survival (OS), measured from surgery to death or last follow-up in April 2022.

RESULTS

The OS median was 45.4 months for all patients after oesophagectomy. Smokers had a significantly lower median OS of 36.6 months compared with Non-Smokers with 66.2 months (p<0.001). Similarly, Drinkers had a lower median OS of 34.4 months compared with Non-Drinkers with 52.0 months (p<0.001). PSM analysis confirmed the significant differences in OS between Smokers and Non-Smokers (p=0.002) and between Drinkers and Non-Drinkers (p=0.002). Subgroup analyses showed no significant differences in OS between Group Another and Group Both, Group Smoker-Only and Group Drinker-Only, and Group Drinker-Only and Group Both. (figure 4) CONCLUSION: Smoking and drinking were associated with significantly reduced OS in patients. However, no significant differences were found between the subgroups of patients who only smoked, only drank, or engaged in both habits.

The AP-2 Family of Transcription Factors-Still Undervalued Regulators in Gastroenterological Disorders

Activating enhancer-binding protein 2 (AP-2) is a family of transcription factors (TFs) that play crucial roles in regulating embryonic and oncogenic development. In addition to splice isoforms, five major family members encoded by the TFAP2A/B/C/D/E genes have been identified in humans, i.e., AP-2α/β/γ/δ/ε. In general, the first three TFs have been studied more thoroughly than AP-2δ or AP-2ε. Currently, there is a relatively limited body of literature focusing on the AP-2 family in the context of gastroenterological research, and a comprehensive overview of the existing knowledge and recommendations for further research directions is lacking. Herein, we have collected available gastroenterological data on AP-2 TFs, discussed the latest medical applications of each family member, and proposed potential future directions. Research on AP-2 in gastrointestinal tumors has predominantly been focused on the two best-described family members, AP-2α and AP-2γ. Surprisingly, research in the past decade has highlighted the importance of AP-2ε in the drug resistance of gastric cancer (GC) and colorectal cancer (CRC). While numerous questions about gastroenterological disorders await elucidation, the available data undoubtedly open avenues for anti-cancer targeted therapy and overcoming chemotherapy resistance. In addition to gastrointestinal cancers, AP-2 family members (primarily AP-2β and marginally AP-2γ) have been associated with other health issues such as obesity, type 2 diabetes, liver dysfunction, and pseudo-obstruction. On the other hand, AP-2δ has been poorly investigated in gastroenterological disorders, necessitating further research to delineate its role. In conclusion, despite the limited attention given to AP-2 in gastroenterology research, pivotal functions of these transcription factors have started to emerge and warrant further exploration in the future.

Combined effects of smoking and alcohol consumption on the risk of liver cancer according to metabolic syndrome: A nested case-control study in South Korea

Tobacco and alcohol may interact to increase the risk of liver cancer, which might be modified by other risk factors. Their combined effects in the context of metabolic syndrome (MetS) remain unclear. Given the increasing prevalence of MetS, this nested case-control study was conducted to evaluate the combined effects of smoking and alcohol consumption on liver cancer risk with stratification by MetS. We included 15,352 liver cancer patients and 92,112 matched controls who attended the nationwide general health examination during 2009-2019, using a customized database (N = 5,545,835) from the Korean National Health Insurance Service. Liver cancer risk according to smoking and alcohol consumption was estimated using conditional multivariable logistic regression. Additive and multiplicative interactions between these two factors were assessed. Results showed that in men, dual current users were at a significantly higher risk of liver cancer compared with dual nonusers, adjusted odds ratio (aOR) = 1.61, 95% confidence interval: (1.50, 1.72). Interactions were detected between light-to-moderate alcohol consumption (0.1-28 g/day) and heavy smoking (>20 pack-years) on additive scale, relative excess risk due to interaction = 0.34 (0.16, 0.51), attributable proportion = 0.22 (0.11, 0.33), synergy index = 2.75 (1.85, 3.66), and multiplicative scale, aOR for the product term = 1.28 (1.11, 1.49). An additive interaction was also revealed between light-to-moderate drinking and light-to-moderate smoking in the MetS subgroup. In women, light-to-moderate drinking/nonsmoking was negatively associated with the risk in the non-MetS subgroup. In conclusion, a holistic health promotion program should target male dual users of tobacco cigarettes and alcohol, including light-to-moderate users, especially those with MetS.

Investigating Genetic Overlap between Alzheimer's Disease, Lipids, and Coronary Artery Disease: A Large-Scale Genome-Wide Cross Trait Analysis

There is evidence to support a link between abnormal lipid metabolism and Alzheimer's disease (AD) risk. Similarly, observational studies suggest a comorbid relationship between AD and coronary artery disease (CAD). However, the intricate biological mechanisms of AD are poorly understood, and its relationship with lipids and CAD traits remains unresolved. Conflicting evidence further underscores the ongoing investigation into this research area. Here, we systematically assess the cross-trait genetic overlap of AD with 13 representative lipids (from eight classes) and seven CAD traits, leveraging robust analytical methods, well-powered large-scale genetic data, and rigorous replication testing. Our main analysis demonstrates a significant positive global genetic correlation of AD with triglycerides and all seven CAD traits assessed-angina pectoris, cardiac dysrhythmias, coronary arteriosclerosis, ischemic heart disease, myocardial infarction, non-specific chest pain, and coronary artery disease. Gene-level analyses largely reinforce these findings and highlight the genetic overlap between AD and three additional lipids: high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), and total cholesterol. Moreover, we identify genome-wide significant genes (Fisher's combined p value [FCPgene] < 2.60 × 10-6) shared across AD, several lipids, and CAD traits, including WDR12, BAG6, HLA-DRA, PHB, ZNF652, APOE, APOC4, PVRL2, and TOMM40. Mendelian randomisation analysis found no evidence of a significant causal relationship between AD, lipids, and CAD traits. However, local genetic correlation analysis identifies several local pleiotropic hotspots contributing to the relationship of AD with lipids and CAD traits across chromosomes 6, 8, 17, and 19. Completing a three-way analysis, we confirm a strong genetic correlation between lipids and CAD traits-HDL and sphingomyelin demonstrate negative correlations, while LDL, triglycerides, and total cholesterol show positive correlations. These findings support genetic overlap between AD, specific lipids, and CAD traits, implicating shared but non-causal genetic susceptibility. The identified shared genes and pleiotropic hotspots are valuable targets for further investigation into AD and, potentially, its comorbidity with CAD traits.

Associations of genetically predicted iron status with 24 gastrointestinal diseases and gut microbiota: a Mendelian randomization study

Background

Iron status has been implicated in gastrointestinal diseases and gut microbiota, however, confounding factors may influence these associations.

Objective

We performed Mendelian randomization (MR) to investigate the associations of iron status, including blood iron content, visceral iron content, and iron deficiency anemia with the incidence of 24 gastrointestinal diseases and alterations in gut microbiota.

Methods

Independent genetic instruments linked with iron status were selected using a genome-wide threshold of p = 5 × 10-6 from corresponding genome-wide association studies. Genetic associations related to gastrointestinal diseases and gut microbiota were derived from the UK Biobank, the FinnGen study, and other consortia.

Results

Genetically predicted higher levels of iron and ferritin were associated with a higher risk of liver cancer. Higher levels of transferrin saturation were linked to a decreased risk of celiac disease, but a higher risk of non-alcoholic fatty liver disease (NAFLD) and liver cancer. Higher spleen iron content was linked to a lower risk of pancreatic cancer. Additionally, higher levels of liver iron content were linked to a higher risk of NAFLD and liver cancer. However, certain associations lost their statistical significance upon accounting for the genetically predicted usage of cigarettes and alcohol. Then, higher levels of iron and ferritin were associated with 11 gut microbiota abundance, respectively. In a secondary analysis, higher iron levels were associated with lower diverticular disease risk and higher ferritin levels with increased liver cancer risk. Higher levels of transferrin saturation were proven to increase the risk of NAFLD, alcoholic liver disease, and liver cancer, but decrease the risk of esophageal cancer. MR analysis showed no mediating relationship among iron status, gut microbiota, and gastrointestinal diseases.

Conclusion

This study provides evidence suggesting potential causal associations of iron status with gastrointestinal diseases and gut microbiota, especially liver disease.

Chronic cigarette smoke exposure masks pathological features of Helicobacter pylori infection while promoting tumor initiation

Gastric cancer is the fifth most common cancer and the fifth leading cause of cancer deaths worldwide. Chronic infection by the bacterium Helicobacter pylori is the most prominent gastric cancer risk factor, but only 1-3% of infected individuals will develop gastric cancer. Cigarette smoking is another independent gastric cancer risk factor, and H. pylori- infected smokers are at a 2-11-fold increased risk of gastric cancer development, but the direct impacts of cigarette smoke on H. pylori pathogenesis remain unknown. In this study, male C57BL/6 mice were infected with H. pylori and began smoking within one week of infection. The mice were exposed to cigarette smoke (CS) five days/week for 8 weeks. CS exposure had no notable impact on gross gastric morphology or inflammatory status compared to filtered-air (FA) exposed controls in mock-infected mice. However, CS exposure significantly blunted H. pylori- induced gastric inflammatory responses, reducing gastric atrophy and pyloric metaplasia development. Despite blunting these classic pathological features of H. pylori infection, CS exposures increased DNA damage within the gastric epithelial cells and accelerated H. pylori- induced dysplasia onset in the INS-GAS gastric cancer model. These data suggest that cigarette smoking may clinically silence classic clinical symptoms of H. pylori infection but enhance the accumulation of mutations and accelerate gastric cancer initiation.

Gastroesophageal reflux disease increases the risk of rheumatoid arthritis: a bidirectional two-sample Mendelian randomization study

Rheumatoid arthritis (RA) is a common autoimmune disease, and some observational studies have indicated an association between Gastroesophageal Reflux Disease (GERD) and RA. However, the causal relationship between the two remains uncertain. We used Mendelian randomization (MR) to assess the causal relationship between GERD and RA. Two-sample Mendelian randomization analysis was performed using pooled data from large-scale genome-wide association studies. In addition, we performed multivariate MR analyses to exclude confounding factors between GERD and RA, including smoking quantity, drinking frequency, BMI, depression, and education attainment. The MR results for GERD on RA suggested a causal effect of the genetic susceptibility of GERD on RA (discovery dataset, IVW, odds ratio [OR] = 1.41, 95% confidence interval [CI] 1.22-1.63, p = 2.81 × 10-6; validation dataset, IVW, OR = 1.38, 95% CI 1.23-1.55, P = 1.76 × 10-8). Multivariate MR analysis also supports this result. But the results of the reverse MR analysis did not reveal compelling evidence that RA can increase the risk of developing GERD. Our bidirectional Two-Sample Mendelian randomization analysis and multivariate MR analysis provide support for the causal effect of GERD on RA. This discovery could offer new insights for the prevention and treatment of RA.

The Causal Effects between Mood Swings and Gastrointestinal Diseases: A Mendelian Randomization Study

Background

Numerous studies have examined the links between mental disorders such as depression and bipolar disorder, and gastrointestinal (GI) diseases. However, few studies have investigated the link between mood swings and GI diseases. Given the impact of mood swings on various conditions and the growing comprehension of the gut-brain axis, this study aims to explore their causal relationship using Mendelian randomization (MR) methods.

Methods

Single-nucleotide polymorphisms (SNPs) associated with mood swings were obtained from a recent study. SNPs associated with GI diseases were identified from the FinnGen project. We conducted two-sample bidirectional MR analyses using three methods, primarily the inverse variance weighting (IVW) method. Furthermore, we performed sensitivity analyses and false discovery rate (FDR) analysis to validate the accuracy and robustness of the results.

Results

Bidirectional MR analysis revealed significant causal effects between mood swings and GI diseases according to the IVW method (odds ratio (OR): 1.213; 95% confidence interval (CI): 1.118-1.316; P = 3.490e-6; P FDR = 8.730e-5). Mood swings were linked to an increased risk for 11 of 24 diseases, including five upper GI diseases (gastroesophageal reflux disease (GERD), acute gastritis, gastroduodenal ulcer, duodenal ulcer, and functional dyspepsia), two lower GI diseases (diverticular disease of the intestine and irritable bowel syndrome (IBS)) and four hepatobiliary and pancreatic diseases (nonalcoholic fatty liver disease (NAFLD), chronic pancreatitis, acute pancreatitis, and pancreatic cancer). Inverse MR analysis showed no causal relationship between 24 GI diseases and mood swings.

Conclusions

This comprehensive MR analysis suggests that genetically predicted mood swings may be a risk factor in the development of GI diseases. Interventions for mood swings may help to treat GI diseases.

Roles of long non‑coding RNA SNHG16 in human digestive system cancer (Review)

The incidence of tumors in the human digestive system is relatively high, including esophageal cancer, liver cancer, pancreatic cancer, gastric cancer and colorectal cancer. These malignancies arise from a complex interplay of environmental and genetic factors. Among them, long non‑coding RNAs (lncRNAs), which cannot be translated into proteins, serve an important role in the development, progression, migration and prognosis of tumors. Small nucleolar RNA host gene 16 (SNHG16) is a typical lncRNA, and its relationship with digestive system tumors has been widely explored. The prevailing hypothesis suggests that the principal molecular mechanism of SNHG16 in digestive system tumors involves it functioning as a competitive endogenous RNA that interacts with other proteins, regulates various genes and influences a downstream target molecule. The present review summarizes recent research on the relationship between SNHG16 and numerous types of digestive system cancer, encompassing its biological functions, underlying mechanisms and potential clinical implications. Furthermore, it outlines the association between SNHG16 expression and pertinent risk factors, such as smoking, infection and diet. The present review indicated the promise of SNHG16 as a potential biomarker and therapeutic target in human digestive system cancer.

A dose-response correlation between smoking and severity of acute pancreatitis: a propensity score-matched study

Background

Acute pancreatitis, among the most prevalent gastrointestinal disorders, exhibits a continual rise in its incidence recent years. This study endeavor to explore the correlation between smoking exposure and the severity of acute pancreatitis (AP).

Methods

Five hundred and eight patients diagnosed as acute pancreatitis (AP) were included in our data analysis. Patients were categorized based on their smoking pack-years into four groups: light, moderate, heavy, and non-smokers. Outcomes were classified as two: "mild acute pancreatitis (MAP)" and "moderately severe acute pancreatitis (MSAP) or severe acute pancreatitis (SAP)". We conducted propensity score matching (PSM) to adjust confounding factors and multivariable logistic regression analysis to determine adjusted odds ratios and 95% confidence intervals. Additionally, a dose-dependent association analysis between smoking exposure and the incidence rate of "MSAP or SAP" was performed.

Results

Smokers exhibited a higher risk of "MSAP or SAP" compared to non-smokers, both before (17.1 vs. 54.9%, p < 0.001) and after (9.4 vs. 24.7%, p < 0.001) PSM. With an area under the ROC curve of 0.708, smoking showed a moderate level of predictive ability. Furthermore, propensity score matching analysis showed that patients who smoked compared to non-smokers had significantly higher risks of "MSAP or SAP" for light smoking (OR 3.76, 95% CI 1.40-10.07, p = 0.008), moderate smoking (OR 4.94, 95% CI 2.23-10.92, p < 0.001), and heavy smoking (OR 8.08, 95% CI 3.39-19.25, p < 0.001).

Conclusion

Smoking is an independent risk factor that can raise the severity of pancreatitis. Moreover, the severity of acute pancreatitis escalates in tandem with the accumulation of pack-years of smoking.

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.

Esophageal cancer global burden profiles, trends, and contributors

OBJECTIVE

This study aimed to provide a comprehensive overview of the global burden of esophageal cancer (EC) and determine the temporal trends and factors influencing changes in the global burden.

METHODS

The latest incidence and mortality data for EC worldwide were obtained from GLOBALCAN 2022. The mortality and disability-adjusted life years (DALYs) rates for EC from 1990-2019 were sourced from the 2019 Global Burden of Diseases. Trends in EC mortality and DALYs attributable to 11 risk factors or clusters of risk were analyzed using the joinpoint regression model. The trends in age-related EC burden were assessed using a decomposition approach.

RESULTS

An estimated 511,054 new cases of EC were diagnosed in 2022 with 445,391 deaths worldwide. Approximately 75% of cases and deaths occurred in Asia. Nearly 50% of global EC deaths and DALYs were attributed to tobacco use in men in 2019, while 20% were attributed to high body mass index (BMI) in women. From 1990-2019, EC deaths and DALYs attributable to almost all risk factors had declining trends, while EC deaths and DALYs attributed to high BMI in men had upward trends. The age-related EC burden exhibited an upward trend driven by population growth and aging, which contributed to 307.4 thousand deaths and 7.2 million DALYs due to EC.

CONCLUSIONS

The EC burden remains substantial worldwide. Effective tobacco and obesity control measures are critical for addressing the risk-attributable burden of EC. Population growth and aging pose challenges for EC prevention and control efforts.

Factors influencing quality of life in early-stage upper gastrointestinal cancer patients in Nanchong city: a qualitative study

OBJECTIVES

To identify the determinants of quality of life (QoL) among early-stage upper gastrointestinal cancer (UGIC) patients in Nanchong City to inform the development of targeted treatment plans.

METHODS

In this retrospective study, 642 patients diagnosed with UGIC were included. A phenomenological approach was employed, involving in-depth face-to-face interviews to explore patients' real-life experiences with QoL, with an emphasis on spiritual and psychological aspects. Data analysis followed Colaizzi's seven-step method. Statistical analyses included one-way Analysis of Variance (ANOVA), t-tests, binary logistic regression, and Pearson correlation tests.

RESULTS

QoL was significantly reduced in patients with early-stage GI cancer (P<0.001), with prevalent symptoms of anxiety and depression necessitating focused psychological interventions and enhanced medical care. Influential factors on QoL included income, health insurance coverage, illness duration, and levels of anxiety and depression (P<0.001). A strong negative correlation was observed between QoL scores and both the Hamilton Anxiety Scale (r=-0.7808, P<0.001) and the Hamilton Depression Rating Scale (r=-0.7493, P<0.001).

CONCLUSION

This study underscores the substantial impact of anxiety and depression on the QoL of patients with early-stage UGIC. The findings provide a theoretical basis for implementing comprehensive long-term care strategies.

Association between serum total cholesterol and the development of gastric cancer: A two-way two-sample Mendelian randomization study

Previous epidemiologic studies have suggested a potential negative correlation between total cholesterol (TC) and Gastric cancer (GC); however, several observational studies have shown conflicting results and have failed to provide definitive evidence for a causal relationship between TC and GC. Therefore, we conducted a 2-sample bidirectional Mendelian randomization (MR) study to explore the genetic correlation and potential causal relationship between the 2 variables. We screened for single nucleotide polymorphisms (SNPs) associated with TC and GC utilizing a large-scale genome-wide association study (GWAS) public database. The causal relationship was analyzed using 5 MR analysis methods: inverse variance weighting (IVW), weighted median, MR-Egger regression, weighted mode, and simple mode. Additionally, reverse MR analysis was performed to evaluate the possibility of reverse causality. Sensitivity analyses were conducted, including heterogeneity tests, horizontal multiple validity tests, and leave-one-out tests. After meticulous screening, 79 SNPs were identified as instrumental variables (IVs). The IVW method revealed a causal relationship between TC and GC (OR = 0.844; 95% CI: 0.741-0.961; P = .01). Sensitivity analyses did not detect significant horizontal pleiotropy. Though heterogeneity was observed in the forward MR analysis (IVW, Qp = 0.0006), the results remained reliable as we utilized the IVW random-effects model as the primary analytical method. Furthermore, inverse MR analysis found no evidence of reverse causality between TC and GC, effectively ruling out the influence of GC on the reverse causality of TC. Our MR study provided evidence of a causal association between TC and GC, suggesting that TC acts as a protective factor against GC due to its negative association with the disease.

Dissecting the association between gut microbiota, body mass index and specific depressive symptoms: a mediation Mendelian randomisation study

Background

Observational studies highlight the association between gut microbiota (GM) composition and depression; however, evidence for the causal relationship between GM and specific depressive symptoms remains lacking.

Aims

We aimed to evaluate the causal relationship between GM and specific depressive symptoms as well as the mediating role of body mass index (BMI).

Methods

We performed a two-sample Mendelian randomisation (MR) analysis using genetic variants associated with GM and specific depressive symptoms from genome-wide association studies. The mediating role of BMI was subsequently explored using mediation analysis via two-step MR.

Results

MR evidence suggested the Bifidobacterium genus (β=-0.03; 95% CI -0.05 to -0.02; p<0.001 and β=-0.03; 95% CI -0.05 to -0.02; p<0.001) and Actinobacteria phylum (β=-0.04; 95% CI -0.06 to -0.02; p<0.001 and β=-0.03; 95% CI -0.05 to -0.03; p=0.001) had protective effects on both anhedonia and depressed mood. The Actinobacteria phylum also had protective effects on appetite changes (β=-0.04; 95% CI -0.06 to -0.01; p=0.005), while the Family XI had an antiprotective effect (β=0.03; 95% CI 0.01 to 0.04; p<0.001). The Bifidobacteriaceae family (β=-0.01; 95% CI -0.02 to -0.01; p=0.001) and Actinobacteria phylum (β=-0.02; 95% CI -0.03 to -0.01; p=0.001) showed protective effects against suicidality. The two-step MR analysis revealed that BMI also acted as a mediating moderator between the Actinobacteria phylum and appetite changes (mediated proportion, 34.42%) and that BMI partially mediated the effect of the Bifidobacterium genus (14.14% and 8.05%) and Actinobacteria phylum (13.10% and 8.31%) on both anhedonia and depressed mood.

Conclusions

These findings suggest a potential therapeutic effect of Actinobacteria and Bifidobacterium on both depression and obesity. Further studies are required to translate these findings into clinical practice.

ΔNp63α promotes cigarette smoke-induced renal cancer stem cell activity via the Sonic Hedgehog pathway

Cigarette smoke (CS) has been generally recognized as a chief carcinogenic factor in renal cell carcinoma (RCC). The stimulative effect of CS on renal cancer stem cells (RCSCs) has been described previously. The Sonic Hedgehog (SHH) pathway plays an essential role in self-renewal, cell growth, drug resistance, metastasis, and recurrence of cancer stem cells (CSCs). Renal cancer-related gene ΔNp63α is highly expressed in renal epithelial tissues and contributes to the RCSCs characteristics of tumors. The aim of this study was to elucidate the role of ΔNp63α and the SHH pathway on the activity of RCSCs induced by CS through a series of in vivo and in vitro studies. It was shown that in renal cancer tissues, ΔNp63α and RCSCs markers in smokers are expressed higher than that in non-smokers. RCSCs were effectively enriched by tumor sphere formation assay. Besides, CS increased the expression of RCSCs markers and the capability of sphere-forming in vitro and in vivo. Moreover, the SHH pathway was activated, and the specialized inhibitor alleviated the promotion of CS on RCSCs. ΔNp63α activated the SHH pathway and promoted CS-induced enhancement of RCSCs activity. These findings indicate that ΔNp63α positively regulates the activity of CS-induced RCSCs via the SHH pathway.

Association between type 2 diabetes, alcohol intake frequency, age at menarche, and gallbladder cancer: a two-sample Mendelian randomization study

Background

Gallbladder cancer (GBC) is a rare malignancy of the digestive tract, characterized by a remarkably poor prognosis. Currently, there is a controversy on the relationship between type 2 diabetes (T2D) and GBC. Additionally, no definitive conclusions were established regarding the causal relationships between alcohol intake frequency (AIF), age at menarche (AAM) and GBC. The objective of this study was to elucidate the causal association between T2D, AIF, AAM, and GBC.

Methods

Single-nucleotide polymorphisms (SNPs) associated with exposures and outcomes were sourced from the Integrative Epidemiology Unit (IEU) Open Genome-Wide Association Study (GWAS) database. Specifically, the data of GBC comprised 907 East Asians (pathological results of all cases were registered into Biobank Japan) and 425,707 SNPs; T2D comprised 655,666 Europeans with 5,030,727 SNPs; AIF comprised 462,346 Europeans and 9,851,867 SNPs; AAM comprised 243,944 Europeans and 9,851,867 SNPs. The measurement of exposure traits is collected uniformly from the UK Biobank (UKB) database and presented in the form of standard deviation (SD) or the logarithmic form of the odds ratio (logOR). We employed a two-sample Mendelian randomization (MR) analysis to discern the causalities between T2D, AIF, AAM, and GBC. Sensitivity analyses were conducted to identify and address potential heterogeneity, horizontal pleiotropy, and outliers.

Results

Our findings indicated that T2D reduced GBC risk [odds ratio (OR) =0.044; 95% confidence interval (CI): 0.004-0.55; P=0.015, inverse variance-weighted (IVW)]. However, no causal relationship was observed between AIF (OR =0.158; 95% CI: 5.33E-05 to 466.84; P=0.65, IVW), AAM (OR =0.19; 95% CI: 0.0003-140.34; P=0.62, IVW), and GBC. Sensitivity analysis revealed no evidence of horizontal pleiotropy, heterogeneity, or outliers, suggesting the robustness and reliability of our conclusions.

Conclusions

T2D emerged as a potentially protective factor against GBC, whereas neither AIF nor AAM demonstrated a causal relationship with GBC risk. Regulation of glucose metabolism may be one of the methods for preventing GBC.

Dietary patterns suggest that dark chocolate intake may have an inhibitory effect on oral cancer: a Mendelian randomization study

Background

Previous studies reported that variations in dietary intake patterns substantially impact human health, specifically tumorigenesis. However, confounding factors in previous cohort studies have obscured the relationship between dietary differences and the risk of oral cancer (OC).

Materials and methods

We developed an outcome dataset from genome-wide association studies (GWAS) data on three OCs within the GAME-ON project, using GWAS-META merging. We extracted 21 dietary exposures, including 10 dietary patterns, 6 vitamins, and 5 micronutrients, from the UK Biobank database, using the inverse variance weighting method as the primary statistical method. Sensitivity analysis was conducted to detect heterogeneity and pleiotropy. Serum metabolite concentrations were adjusted using multivariate Mendelian randomization.

Results

Of the 10 analyzed dietary patterns, 8 showed no significant association with the risk of developing OC. Consumption of dark chocolate (inverse variance weighted [IVW]: Odds ratio (OR) = 0.786, 95% confidence interval [CI]: 0.622-0.993, p = 0.044) and sweet pepper exhibited an inverse relationship with OC risk (IVW: OR = 0.757, 95% CI: 0.574-0.997, p = 0.048). Reverse MR analysis revealed no reverse causality. Furthermore, no significant correlation was observed between the intake of 6 vitamins and 5 micronutrients and the risk of developing OC. After using multivariable MR to adjust for serum caffeine, linoleate, theophylline, and theobromine metabolism levels, consuming dark chocolate was unrelated to a decreased risk of OC. After adjusting each serum metabolite individually, the observed p-values deviated from the original values to varying degrees, indicating that the components of dark chocolate could have different effects. Among these components, theophylline demonstrated the most significant inhibitory effect.

Conclusion

This study demonstrated a causal relationship between the intake of dark chocolate and sweet peppers and a lower risk of OC. The components of dark chocolate could have different effects.