Coffee and Caffeine Consumption and Risk of Kidney Stones: A Mendelian Randomization Study

The causal relationship between gut microbiota and preterm birth: a two-sample Mendelian randomization study

BACKGROUND

Preterm birth, a significant global health concern, has been associated with alterations in the gut microbiota. However, the causal nature of this relationship remains uncertain due to the limitations inherent in observational studies.

PURPOSE

To investigate the potential causal relationship between gut microbiota imbalances and preterm birth.

METHODS

We conducted a two-sample Mendelian randomization (MR) study using genome-wide association study (GWAS) data from the MiBioGen consortium focusing on microbiota and preterm birth. Single nucleotide polymorphisms (SNPs) associated with the microbiota were selected as instrumental variables. The inverse variance weighting (IVW) method was used to estimate causality. We confirmed pleiotropy and identified and excluded outlier SNPs using MR-PRESSO and MR-Egger regression. Cochran's Q test was applied to assess heterogeneity among SNPs, and a leave-one-out analysis was performed to evaluate the influence of individual SNPs on overall estimates.

RESULTS

Our findings provide evidence for a causal link between specific components of the gut microbiota and preterm birth, with the identification of relevant metabolites.

CONCLUSION

This study highlights the causal role of gut microbiota imbalances in preterm birth, offering novel insights into the development of preterm birth and potential targets for prevention strategies.

Albuminuria and Mental Illness Risk: Results From National Health and Nutrition Examination Survey 2005-2018 and Mendelian Randomization Analyses

BACKGROUND

Recent evidence suggests a link between albuminuria and mental illness. However, whether this association is stable, and its specific mechanisms remain unclear.

METHODS

The cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Weighted multivariable-adjusted logistic regression, subgroup analysis, interaction tests, and restricted cubic spline (RCS) were conducted to assess the correlation between albuminuria and the risk of mental illness (depression). Subsequently, two-sample Mendelian randomization analyses were performed to investigate the relationship between albuminuria and various mental illnesses (anxiety disorder, persistent delusional disorder, schizophrenia, schizotypal personality disorder, panic disorder, post-traumatic stress disorder [PTSD], obsessive-compulsive disorder, bipolar I disorder, bipolar II disorder, depression, autism, social anxiety disorder).

RESULTS

Albuminuria was consistently found to have a significant association with the risk of depression, regardless of its classification as a continuous or outcome variable. A positive correlation was found between albuminuria and depression in different age groups, gender, race, education attainment, and those with hypertension, coronary heart disease, and diabetes. Further, there is a positive correlation between albuminuria and the occurrence of schizophrenia and persistent delusional disorder.

CONCLUSION

There is a close association between albuminuria and mental illness, with albuminuria being a risk factor for schizophrenia and persistent delusional disorder. Further research is needed to establish the specific connections.

Association Between T2DM, TyG Index, Multiple Sclerosis, and Rheumatoid Arthritis: Insights into Potential Mechanisms

Abundant research indicates that type 2 diabetes mellitus (T2DM) and insulin resistance (IR) have a certain association with autoimmune-related diseases (ARDs). However, the conclusions remain elusive. Therefore, this study aimed to explore whether there are causal associations between T2DM and IR indicator, triglyceride-glucose (TyG) index with ARDs, and evaluate the impact of immune cells. Comprehensive Mendelian randomization (MR) analysis combined with Bayesian colocalization was employed to investigate the relationship between T2DM, TyG index, ARDs, and specific-marker immune cells by extracting summary-level data from various genome-wide association studies (GWASs). Further investigations utilizing single-cell RNA sequencing (scRNA-seq) analysis were performed to explore the potential molecular mechanisms underlying the MR analysis results. Causal associations of T2DM with multiple sclerosis (MS) and rheumatoid arthritis (RA) were detected. Additionally, the TyG index was genetically predicted to be associated with MS. Furthermore, immune cells were found to be related to T2DM and TyG index, of which CD3 on naive CD8 + T cell mediate the effect on the association between TyG index and multiple sclerosis (MS). Additionally, genetic variation of TCF7L2 and TNFSF13B were assessed to play a crucial role in the aforementioned associations supported by colocalization analysis. This study identified T2DM and IR related to increased risk of MS and RA. The analysis of relevant immune cells and shared genetic loci provides a novel direction for exploring comorbidity mechanisms.

Both absolute and relative sugar-sweetened beverage intake are associated with kidney stones in U.S. middle-aged and young adults

BACKGROUND

Sugar-sweetened beverage (SSB) intake is currently a public health concern. However, the relationship between SSB intake and the risk of kidney stones in middle-aged and young populations has not been thoroughly investigated.

METHODS

The National Health and Nutrition Examination Survey (NHANES) database (for 2007-2016) was used. SSB intake was assessed using 24-hour dietary recall interviews and evaluated through two distinct metrics: (1) absolute intake, defined as the total energy derived from SSB, and (2) relative intake, expressed as the percentage of total daily energy intake contributed by SSB. Multivariable logistic regression models were used to investigate the association between SSB intake and the prevalence of kidney stones, with stratified and interaction analyses performed for covariates. All analyses accounted for sample weighting to ensure accurate representation.

RESULTS

The study analyzed data from 15,779 nationally representative participants, of whom 1,224 had kidney stones. After adjusting for potential covariates, both the absolute intake of SSB (per 100 kcal/d) and the relative intake (per 1%) were positively associated with the risk of kidney stones. The odds ratios (ORs) were 1.065 (95% confidence interval [CI]: 1.038, 1.093) and 1.015 (95% CI: 1.009, 1.022), respectively. Compared to individuals who do not consume SSB, kidney stones risk increased with absolute SSB intake across ascending tertiles: the ORs were 1.231 (95% Cl: 0.995, 1.523), 1.335 (95% Cl: 1.075, 1.658), and 1.664 (95% Cl: 1.353, 2.048) for the lowest to highest tertiles, respectively. The ORs corresponding to the respective tertiles of relative intake were 1.224 (95% CI: 0.991, 1.511), 1.394 (95% CI: 1.128, 1.723), and 1.626 (95% CI: 1.317, 2.009). This association remained generally stable across stratified analyses. Additionally, obesity status and alcohol consumption status significantly interacted with the relative SSB intake-kidney stones relationship.

CONCLUSION

In middle-aged and young adults, higher SSB intake is linked to a greater kidney stone risk, indicating that limiting consumption may aid in prevention.

Exploring the effect of SGLT2 inhibitors on the risk of primary open-angle glaucoma using Mendelian randomization analysis

This study aimed to evaluate the causal effect of sodium-glucose cotransporter protein 2 (SGLT2) inhibition on primary open-angle glaucoma (POAG) and explore potential mechanisms. A drug-targeted Mendelian randomization (MR) study was conducted using genetic variation related to SGLT2 inhibition, based on SGLT2 gene expression and glycated hemoglobin levels. Genetic summary statistics for POAG were obtained from the FinnGen consortium and a multi-ancestry genome-wide association study. Glaucomatous endophenotype data were also incorporated. A two-step MR analysis was performed to examine whether pathways related to obesity, blood pressure, lipid levels, oxidative stress, and inflammation mediated the association between SGLT2 inhibition and POAG. Genetically predicted SGLT2 inhibition was associated with a reduced risk of POAG (OR: 0.28; 95% CI: 0.12 to 0.63; P = 2.22 × 10- 3), confirmed in a multi-ancestry validation cohort. It was also associated with decreased optic cup area, reduced vertical cup-disc ratio, and increased optic disc area. Mediation analysis indicated that the effect of SGLT2 inhibition on POAG was partly mediated by diastolic blood pressure (4.8%). This study suggests that SGLT2 inhibition is a promising therapeutic target for POAG. However, further large-scale randomized controlled trials are required to confirm these findings.

Causal correlations between inflammatory proteins and heart failure: A two-sample Mendelian randomization analysis

AIMS

Inflammation plays a critical role in both the development and progression of heart failure (HF), which is a leading cause of morbidity and mortality worldwide. However, the causality between specific inflammation-related proteins and HF risk remains unclear. This study aims to investigate the genetically supported causality between inflammatory proteins and HF using a two-sample Mendelian randomization (MR) analysis.

METHODS AND RESULTS

We utilized genome-wide association study (GWAS) data of 91 inflammation-related proteins as exposures from the SCALLOP Consortium (14,824 participants), alongside outcome GWAS summary statistics from FinnGen (29,218 cases/381,838 controls) and HERMES (47,309 cases/930,014 controls) for HF, to conduct a two-sample MR analysis. For each inflammatory protein, instrumental variables (IVs) were chosen following the three foundational assumptions of the MR analysis, requiring a minimum of three qualifying single nucleotide polymorphisms (SNPs) each with a P < 5e-8. Associations between inflammatory proteins and HF were assessed through inverse-variance weighted (IVW), MR-Egger regression, weighted median and weighted mode analysis. The reliability and validity of the results were evaluated by examining heterogeneity, horizontal pleiotropy, leave-one-out analysis, meta-analysis and reverse MR analysis. Heterogeneity refers to the variation in results across different genetic variants. Horizontal pleiotropy occurs when a genetic variant influences multiple traits through different biological pathways. Addressing both heterogeneity and horizontal pleiotropy is crucial for ensuring the reliability and interpretability of MR results. Our analysis identified associations between three inflammatory proteins and HF risk. Matrix metalloproteinase-1 (MMP-1) (OR, 1.09; 95% CI, 1.00-1.18; P = 0.04) and TNF-beta (OR, 1.05; 95% CI, 1.01-1.09; P = 0.01) were positively associated with HF risk in FinnGen. In contrast, urokinase-type plasminogen activator (uPA) was inversely associated with HF risk in both FinnGen (OR, 0.85; 95% CI, 0.78-0.92; P = 3.27e-5) and HERMES (OR, 0.93; 95% CI, 0.87-0.99; P = 0.03). No evidence of heterogeneity and horizontal pleiotropy was observed in the MR analysis, indicating the robustness of our findings. A meta-analysis further supported this association, indicating a reduced risk (OR, 0.89; 95% CI, 0.81-0.98; P = 0.02). No reverse causality was found between HF and these three inflammatory proteins (P > 0.05 for all).

CONCLUSIONS

This study provides genetically supported evidence of the causal association of specific inflammatory proteins with HF risk. The positive association of MMP-1 and TNF-beta with HF suggests their roles in disease pathogenesis, whereas the inverse association of the uPA indicates its potential protective effect. Our findings highlight the potential of targeting specific inflammatory pathways as a therapeutic strategy for HF.

Exploring the Impact of Neuroticism on Lung Cancer Risk: Insights From Mediated Mendelian Randomization

OBJECTIVE

This study aimed to explore the potential association between neuroticism and lung cancer.

METHODS

We conducted analyses on publicly accessible aggregated data from genome-wide association studies (GWAS) that included individuals of European descent. The objective was to identify single nucleotide polymorphisms (SNPs) significantly associated with neuroticism and utilize them as instrumental variables in a two-sample Mendelian randomization framework to evaluate the gender-specific causal link between neuroticism and lung cancer risk. We applied four statistical methods: Inverse variance weighting (IVW), weighted median, MR-Egger regression, and weighted mode. Our analysis also considered the mediating effect of educational attainment on this relationship.

RESULTS

We selected 67 SNPs associated with neuroticism at genome-wide significance levels from GWAS datasets. Our primary findings using IVW suggest a notable increase in lung cancer risk associated with neuroticism across the general population (odds ratio [OR] = 1.175; 95% confidence interval [CI] 1.020-1.354, p = 0.026). Gender-specific analysis revealed that neuroticism posed a slight but significant risk increase in men (OR = 1.006; 95% CI 1.000-1.012, p = 0.045) and women (OR = 1.005; 95% CI 1.002-1.009, p = 0.002), with findings corroborated by the additional statistical methods. Further, evidence from both observational and Mendelian randomization analyses suggests that genetically predicted neuroticism is causally associated with a modestly increased risk of incident lung cancer, with ∼17% of this effect mediated by educational attainment.

CONCLUSIONS

The results from this Mendelian randomization study provide robust evidence supporting a potential association between neuroticism and an increased risk of lung cancer. This association appears more pronounced in men than women. Additionally, educational level serves as a mediator in the nexus between these conditions, suggesting that interventions aimed at increasing educational attainment might mitigate some of the risk neuroticism poses for developing lung cancer.

National analysis of the dietary index for gut microbiota and kidney stones: evidence from NHANES (2007-2018)

Background

Previous studies have highlighted the effects of diet and gut microbiota on the incidence of kidney stones, and the dietary index for gut microbiota (DI-GM) is a new dietary index that accurately represents the variety of gut microbiota. The current study intends to examine the potential correlation between DI-GM and kidney stones.

Methods

Data from the 2007-2018 National Health and Nutrition Examination Survey (NHANES) were employed in this cross-sectional study. The history of kidney stones was assessed using a kidney conditions questionnaire. In order to examine the correlation between DI-GM and kidney stones, multivariate logistic regression was implemented. Additionally, smoothed curve fitting, subgroup analyses, and sensitivity analyses were conducted.

Results

The investigation encompassed a total of 21,587 participants. After adjusting for all potential covariates, we found that DI-GM was negatively related to the incidence of kidney stones (OR = 0.96, 95% CI = 0.93-0.98, p = 0.0021). Compared to those in the lowest quartile, participants in the highest quartile had a lower prevalence of kidney stones (OR = 0.86, 95% CI = 0.75-0.98, p = 0.0252). Additionally, smoothed curve fitting revealed that DI-GM was linearly associated with the incidence of kidney stones. The results of the sensitivity analyses proved the robustness of the main analyses.

Conclusion

A negative correlation between the incidence of kidney stones and DI-GM is supported by the evidence presented in this study. This finding emphasizes the potential benefits of adjusting dietary structure according to DI-GM in reducing the incidence of kidney stones. Further research should validate this discovery by employing longitudinal studies.

GOLPH3 promotes calcium oxalate-induced renal injury and fibrosis through Golgi stress-mediated apoptosis and inflammatory responses

A common urological disorder, calcium oxalate (CaOx) stones are the most common form of kidney stones. Deposition of CaOx crystals leads to tubular damage, interstitial fibrosis, and chronic kidney disease. Understanding the intrinsic mechanisms of kidney stone formation is essential for the prevention of kidney stones and the development of new therapeutic agents. The Golgi apparatus is a key organelle in the secretory pathway of eukaryotic cells, which plays an important role in the sorting, modification, and transport of proteins within the cell, and has been reported to be involved in several diseases, including prostate tumors, gastrointestinal tumors, sepsis, and so on. GOLPH3 is also known as GPP34, GMx33, or MIDAS. It is a glycoprotein that regulates traffic between the trans-Golgi network and the cell membrane. However, its role in renal injury caused by CaOx crystal deposition is still unclear. Results from immunohistochemistry, qRT-PCR, western blot, and public database single nucleotide RNA-seq showed that GOLPH3 was significantly upregulated in kidney stone patients and animal kidneys. Significant inhibition of Golgi stress, apoptosis, and renal fibrosis by GOLPH3 inhibition with siRNA in CaOx-stimulated HK-2 cells. The PI3K\AKT\mTOR signaling pathway was inhibited by GOLPH3 knockdown, which may be associated with reduced inflammatory response and apoptosis, as well as restoration of Golgi morphology and function. In conclusion, GOLPH3 plays a critical role in CaOx-induced kidney injury by promoting Golgi stress and increasing inflammatory responses, apoptosis, and renal fibrosis, suggesting that GOLPH3 is a potential therapeutic target for kidney stones.

The length of night shift work is closely associated with cancer risk: A pan-cancer study of Mendelian randomization study

Night shift work (NSW) has been associated with cancer risk in animal studies, but epidemiological evidence remains insufficient and contradictory. This study sought to investigate the causal association between NSW and 13 common cancers using a two-sample Mendelian randomization (MR) study. Genetic variants associated with NSW were extracted from the UK Biobank and selected as instrumental variables (IVs). Genome-wide association study (GWAS) data for 13 cancers were obtained from relevant consortia and biobanks. Causality was estimated using inverse-variance weighted (IVW), MR-Egger, and weighted median (WM). Sensitivity analyses, including MR-Egger intercept tests, MR-PRESSO, leave-one-out analyses, and funnel plots, were conducted to detect pleiotropy and heterogeneity. A suggestive causal association was found between NSW duration and risks of cervical (IVW: p = 0.028) and gastric cancer (IVW: p = 0.011). No significant associations were observed for other cancers (p > 0.05). These findings suggest the need to reduce NSW duration and limit nocturnal light exposure to maintain circadian rhythms and mitigate cancer risks.

Novel anti-inflammatory properties of mannose oligosaccharides in the treatment of inflammatory bowel disease via LGALS3 modulation

This study investigates the role of Gum Arabic Mannose Oligosaccharides (GA-MOS) in modulating gut microbiota and alleviating symptoms of Inflammatory Bowel Disease (IBD). Employing both in vitro and in vivo models, we explored how GA-MOS influences microbial communities, particularly focusing on their capacity to enhance health-associated bacteria and reduce pathogenic species within the gut environment. Our findings reveal that GA-MOS treatment significantly altered the gut microbiota composition, increasing the abundance of anti-inflammatory bacteria while decreasing pro-inflammatory species, thus contributing to a reduction in gut inflammation and an improvement in intestinal barrier function. Detailed molecular analyses further demonstrated that these changes in microbiota were associated with modifications in the host's immune response, particularly through the suppression of key inflammatory pathways and cytokines involved in IBD progression. These results underscore the potential of dietary polysaccharides like GA-MOS as therapeutic agents in managing dysbiosis and inflammatory conditions in the gut, offering a promising approach for enhancing microbial health and overall disease management in IBD. This study provides novel insights into the bioactive properties of MOS and their interactions with gut microbiota, suggesting broader implications for their use in microbiome-centered therapies.

Association of caffeine intake and sleep duration with bone mineral density: a cross-sectional study from National Health and Nutrition Examination Survey between 2011 and 2018

OBJECTIVE

The association between sleep duration, caffeine intake, and bone mineral density (BMD) is not well understood, with previous studies providing controversial results. This study explores the associations among caffeine intake, sleep duration, and BMD.

METHODS

Data were sourced from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018, including 13,457 participants who self-reported sleep duration and caffeine intake, with BMD measured via dual X-ray absorptiometry. Multivariable linear regression models, adjusted for confounders, were used alongside restricted cubic splines to examine dose-response association.

RESULTS

Of all participants, 6821 (50.7%) were males and 6636 were females (49.3%). The mean caffeine intake and sleep duration were 93.4 mg/day and 7.19 h, respectively. RCS results showed that BMD increased with the increase in caffeine intake, especially in the low dose range of 0-200 mg/day. The dose-response association between sleep duration and BMD showed that sleep durations of 0-6 h may promote the increase of BMD, but after sleep durations greater than 6 h, BMD decreases. After adjustment for potential confounders, compared to the lowest referent quartile, individuals with caffeine intake in quartiles 2, 3, and 4 had a positive correlation with BMD (0.62 95% CI: 0.24-1.37; 0.51 95% CI: 0.22-1.13; 0.75 95% CI: 0.41-1.46; P for trend < 0.05). In covariate-adjusted linear regression models, compared with those sleeping 6 h or less per night, the difference in BMD among those sleeping 6-7 h, 7-8 h, and 8-14.5 h per night were 1.81 (95% CI: 0.4122.71), 1.25 (95% CI: 0.55-2.93), and 0.87 (95% CI: 0.38-1.69). Associations of caffeine intake, sleep duration, and BMD stratified by sex and age failed to reach statistical significance.

CONCLUSIONS

Association might exist between the consumption of caffeine, sleep duration, and BMD; however, when stratified by sex and age, the association did not reach statistical significance.

PLASMA PROTEOME, METABOLOME MENDELIAN RANDOMIZATION IDENTIFIES SEPSIS THERAPEUTIC TARGETS

ABSTRACT

Background : The interrelation between the plasma proteome and plasma metabolome with sepsis presents a multifaceted dynamic that necessitates further research to elucidate the underlying causal mechanisms. Methods : Our investigation used public genome-wide association study data to explore the relationships among the plasma proteome, metabolome, and sepsis, considering different sepsis subgroup. Initially, two-sample Mendelian randomization established causal connections between the plasma proteome and metabolome with sepsis. Subsequently, multivariate and iterative Mendelian randomization analyses were performed to understand the complex interactions in plasma during sepsis. The validity of these findings was supported by thorough sensitivity analyses. Result : The study identified 25 plasma proteins that enhance risk and 34 that act as protective agents in sepsis. After P value adjustment (0.05/1306), ICAM5 emerged with a positive correlation to sepsis susceptibility ( P value = 2.14E-05, OR = 1.10, 95% CI = 1.05-1.15), with this significance preserved across three sepsis subgroup examined. Additionally, 29 plasma metabolites were recognized as risk factors, and 15 as protective factors for sepsis outcomes. After P value adjustment (0.05/997), elevated levels of 1,2,3-benzenetriol sulfate (2) was significantly associated with increased sepsis risk ( P value = 3.37E-05, OR = 1.18, 95% CI = 1.09-1.28). Further scrutiny revealed that this plasma metabolite notably augments the abundance of ICAM5 protein ( P value = 3.52E-04, OR = 1.11, 95% CI = 1.04-1.17), devoid of any detected heterogeneity, pleiotropy, or reverse causality. Mediated Mendelian randomization revealed ICAM5 mediated 11.9% of 1,2,3-benzenetriol sulfate (2)'s total effect on sepsis progression. Conclusion : This study details the causal link between the plasma proteome and metabolome with sepsis, highlighting the roles of ICAM5 and 1,2,3-benzenetriol sulfate (2) in sepsis progression, both independently and through crosstalk.

Threshold effects between caffeine intake and urine flow rate: a population-based cross-sectional study

PURPOSE

The potential benefits of caffeine intake are currently receiving much attention and exploration. Urine flow rate (UFR) is an objective index to comprehensively reflect bladder function. The aim of this study was to investigate the association between caffeine intake and UFR using the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

14,142 participants were enrolled in this study. Weighted multivariate adjusted regression models were used to explore the relationship between caffeine intake and UFR. The dose-response relationships were explored using a restricted cubic spline (RCS) and a threshold effect analysis was conducted based on the inflection points identified by the two-segment linear regression model. In addition, subgroup analysis and sensitivity analysis were applied.

RESULTS

The findings suggested that the intake of caffeine was correlated with improved UFR [Model 3: 0.091 (0.057, 0.126), P value < 0.001]. In addition, the RCS supported a nonlinear relationship between them. The analysis of threshold effect further revealed a specific level of caffeine intake (34.51 mg/day) that exhibited a significant enhancement in UFR. Finally, through re-analyzing the data set obtained after multiple imputation (MI), we obtained similar results.

CONCLUSION

This study found a nonlinear beneficial relationship between caffeine intake and UFR, and revealed the recommended intake of caffeine. The values varied by gender, race, education, and smoking status.

Genetic association between celiac disease and chronic kidney disease: a two-sample Mendelian randomization study

OBJECTIVE

A two-sample Mendelian randomization (MR) analysis was performed to elucidate the causal impact of celiac disease on the risk of chronic kidney disease (CKD).

METHODS

The study comprised data from three genome-wide association studies involving individuals of European ancestry. The study groups included participants with celiac disease (n = 24,269), CKD (n = 117,165), and estimated glomerular filtration rate levels based on serum creatinine (eGFRcrea, n = 133,413). We employed four widely recognized causal inference algorithms: MR-Egger, inverse variance weighted (IVW), weighted median, and weighted mode. To address potential issues related to pleiotropy and overall effects, MR-Egger regression and the MR-PRESSO global test were performed. Heterogeneity was assessed using Cochran's Q test.

RESULTS

We identified 14 genetic variants with genome-wide significance. The MR analysis provided consistent evidence across the various methodologies, supporting a causal relationship between celiac disease and an elevated risk of CKD (odds ratio (OR)IVW = 1.027, p = 0.025; ORweighted median = 1.028, P = 0.049; ORweighted mode = 1.030, p = 0.044). Furthermore, we observed a causal link between celiac disease and a decreased eGFRcrea (ORIVW = 0.997, P = 2.94E-06; ORweighted median = 0.996, P = 1.68E-05; ORweighted mode = 0.996, P = 3.11E-04; ORMR Egger = 0.996, P = 5.00E-03). We found no significant evidence of horizontal pleiotropy, heterogeneity, or bias based on MR-Egger regression, MR-PRESSO, and Cochran's Q test.

CONCLUSION

The results of this study indicate a causal relationship between celiac disease and an increased risk of CKD.

A mendelian randomization study investigating the association between sleep apnea risk and cheese consumption through biomarker analysis

Cheese consumption may play a role in mitigating sleep apnea risk, according to our Mendelian randomization (MR) study. Sleep apnea, a prevalent disorder associated with various health complications, affects millions worldwide, generating interest in dietary interventions. This study analyzed data from the UK Biobank and the FinnGen Biobank, focusing on cheese intake and its potential impact on sleep apnea through various biomarkers. Results revealed a significant inverse association between cheese consumption and sleep apnea risk (OR=0.724, p=0.00478), indicating that higher cheese intake is linked to a reduced likelihood of developing the disorder. Additionally, the analysis identified six biomarkers, including aspartate aminotransferase (1.33 %), urea (3.85 %), cystatin C (2.98 %), sex hormone-binding globulin (1.78 %), testosterone (1.94 %), and diastolic blood pressure (5.46 %), as mediators of this relationship. Notably, cheese consumption influenced levels of 23 biomarkers. These findings underscore the potential of dietary interventions in public health strategies aimed at decreasing sleep apnea prevalence and associated health risks. Overall, this study highlights the complex connections between diet, biomarkers, and sleep apnea, emphasizing the necessity for further research across diverse populations to enhance the generalizability of these results.

Clinical efficacy and safety of the superpulse thulium fiber laser and holmium laser for ureteroscopic lithotripsy in the treatment of upper urinary tract calculi: a randomized, positive control, blinded, single-center clinical study {1}

BACKGROUND

Kidney stone disease is a common problem. The holmium: yttrium-aluminum-garnet (HO:YAG) laser is currently the gold standard laser for ureterorenoscopic (URS) lithotripsy. Recently, the superpulse thulium fiber laser (SP TFL) has shown potential as a substitute for the HO:YAG laser. We aim to compare and evaluate the clinical efficacy and safety of the HO:YAG laser and SP TFL in the treatment of upper urinary calculi in this trial.

METHODS

In this randomized, positive control, blinded management, single-center clinical study, patients with upper urinary calculi will be randomized (1:1) to the experimental group (SP TFL group) or the control group (HO:YAG laser group). Patients in both groups will undergo URS lithotripsy under general anesthesia, and according to the results of randomization, the patients will be treated with an SP TFL (trial group) or a holmium laser (control group). The primary outcome is the stone-free rate at 30 ± 7 days after surgery. The secondary outcomes include the duration of surgery, the duration of laser use, the length of postoperative hospital stay, postoperative clinical indicators, total hospitalization costs, the second-stage stone clearance rate, perioperative complications, the average hemoglobin change, and the mean white blood cell count change.

DISCUSSION

This study aims to evaluate and compare the clinical efficacy and safety of the SP TFL and HO:YAG for URS lithotripsy in the treatment of upper urinary calculi. TRIAL REGISTRATION {2A AND 2B}: chictr.org.cn ChiCTR2300076893. Registered on October 24, 2023, with ChiCTR ( https://www.chictr.org.cn/bin/project/edit?pid=206827 ). PROTOCOL VERSION {3}: August 15, 2023 (V.20230815).

Causal effects of noise and air pollution on multiple diseases highlight the dual role of inflammatory factors in ambient exposures

BACKGROUND

Noise and air pollution are significant environmental threats with proven adverse health effects. However, the causality between these ambient exposures and disease is still largely unknown. This study aims to provide genetic evidence for this gap and investigates the dual role of inflammatory factors, emphasizing the need for integrated public health strategies.

METHODS

We included noise and air pollution as exposures, 91 inflammatory factors as mediators, and 26 diseases as outcomes. We explored causal relationships using Mendelian randomization. To ensure the reliability, we screened single nucleotide polymorphisms (SNPs) closely associated with exposure as instrumental variables (IVs), and assessed the pleiotropy and heterogeneity of these IVs.

RESULTS

Our results suggest that "Hearing difficulty/problems with background noise" increases the risk of hypertension, bronchitis, and menopause; loud music exposure frequency increases the risk of bronchitis; noisy workplace raises the risk of hypertension, coronary heart disease, narcolepsy, and irritable bowel syndrome; NO2 increases the risk of myocardial infarction and chronic heart failure; NOx increases the risk of pneumonia and inflammatory diseases of female pelvic organs; and PM10 increases the risk of myocardial infarction, narcolepsy, and type 2 diabetes; PM2.5-10 increases the risk of developing pneumonia and type 2 diabetes. Furthermore, we found that nine inflammatory factors play a mediating role, of which four play a mediating role in increasing the risk of morbidity and eight play a mediating role in protection against ambient exposures. Finally, we selected SNPs significantly associated with exposure and outcome for enrichment analysis.

CONCLUSIONS

This study provides the first genetic evidence linking noise and air pollution to various diseases, highlighting the dual mediating role of inflammatory factors. Our findings align with the "One Health" framework, emphasizing the interconnectedness of environmental and human health. Integrated public health strategies considering these complex biological responses are essential for promoting overall well-being.

Urinary Stone Composition Analysis of 1465 Patients: The First Series from Azerbaijan

BACKGROUND

Urinary stone disease is a prevalent health issue worldwide, with varying incidence influenced by multiple factors. This study aims to provide the first comprehensive analysis of urinary stone composition in Azerbaijan.

METHODS

A retrospective study was conducted on 1465 patients, aged 1‒83 years, who underwent biochemical urinary stone analysis at the Department of Renal Diseases and Organ Transplantation, Azerbaijan State Security Service Military Hospital, between April 2015 and December 2023. Stone samples were analyzed using Fourier transform infrared (FTIR) spectroscopy. Statistical analyses were performed using the IBM® SPSS software version 29.0.

RESULTS

The cohort had a median age of 45 years, with a male-to-female ratio of 1.65:1. Calcium oxalate stones were the most common (56.2%), followed by uric acid (33.7%), struvite (5.3%), cystine (2.5%), calcium phosphate (1.9%), and xanthine (0.1%) stones. Men had a higher prevalence of calcium oxalate and uric acid stones, while women had more struvite stones. Mixed stones were common, particularly among uric acid and struvite stones. Significant differences in stone composition were observed between age groups and genders, with uric acid stones found predominantly in older individuals.

CONCLUSION

This study highlights the predominance of calcium oxalate stones and the elevated prevalence of uric acid stones in Azerbaijan, emphasizing the need for tailored diagnostic and therapeutic approaches. The high prevalence of mixed stones underscores the complexity of urinary stone disease and the need for comprehensive metabolic evaluation and individualized preventive strategies.

Discovering Novel Loci of Chronic Kidney Disease via Principal Component Analysis-Based Multiple-Trait Genome-Wide Association Study

INTRODUCTION

Chronic kidney diseases (CKD) encompass a spectrum of complex pathophysiological processes. While numerous genome-wide association studies (GWASs) have focused on individual traits such as albuminuria, estimated glomerular filtration rate (eGFR), and eGFR change, there remains a paucity of genetic studies integrating these traits collectively for comprehensive evaluation.

METHODS

In this study, we performed individual GWASs for albuminuria, baseline eGFR, and eGFR slope utilizing data from non-diabetic individuals enrolled from the Taiwan Biobank (TWB). Subsequently, we employed principal component analysis to transform these three quantitative traits into principal components (PCs) and performed GWAS based on these principal components (PC-based GWAS).

RESULTS

The individual GWAS analyses of albuminuria, baseline eGFR, and eGFR slope identified 10, 13, and 210 candidate loci respectively, with 2, 3, and 99 of them representing previously reported loci. PC-based GWAS identified additional 20 novel candidate loci linked to CKD (p values ranging from 5.8 × 10-7 to 9.1 × 10-6). Notably, 4 of these 20 single nucleotide polymorphisms (rs9332641, rs10737429, rs117231653, and rs73360624) exhibited significant associations with kidney expression quantitative trait loci.

CONCLUSION

To our knowledge, this study represents the first PC-based GWAS integrating albuminuria, baseline eGFR, and eGFR slope. Our approach found 20 novel candidate loci suggestively associated with CKD, underscoring the value of integrating multiple kidney traits in unraveling the pathophysiology of this complex disorder.

Causal effect of air pollution on the risk of brain health and potential mediation by gut microbiota

OBJECTIVE

Epidemiologic investigations have examined the correlation between air pollution and neurologic disorders and neuroanatomic structures. Increasing evidence underscores the profound influence of the gut microbiota on brain health. However, the existing evidence is equivocal, and a causal link remains uncertain. This study aimed: to determine if there is a causal connection between four key air pollutants, and 42 neurologic diseases, and 1325 distinct brain structures; and to explore the potential role of the gut microbiota in mediating these associations.

METHODS

Univariable Mendelian randomization (UVMR) and multivariable Mendelian randomization (MVMR) models were deployed to estimate the causal impact of air pollutants (including particulate matter [PM] with aerodynamic diameters <2.5 μm [PM2.5], and <10 μm [PM10]; PM2.5 absorbance; and nitrogen oxides [NOx]) on brain health through various Mendelian randomization methodologies. Lastly, the mediating role of the gut microbiome in the connections between the identified pollutants and neurologic diseases and brain structures was systematically examined.

RESULTS

The potential causal associations of PM2.5, PM2.5 absorbance, PM10, and exposure to NOx, with the risks of intracerebral hemorrhage, hippocampal perivascular spaces, large artery strokes, generalized epilepsy with tonic-clonic seizures, Alzheimer's disease, multiple sclerosis, anorexia nervosa, post-traumatic stress disorder (PTSD), and 420 brain structures, were investigated by UVMR analysis. Following adjustment for air pollutants by MVMR analysis, the genetic correlations between PM10 exposure and PTSD and multiple sclerosis remained significant and robust. Importantly, we observed that phylum Lentisphaerae may mediate the association between PM10 and multiple sclerosis. Additionally, PM2.5 absorbance with a greater risk of reduced thickness in the left anterior transverse temporal gyrus of Heschl and a decreased area in the right sulcus intermedius primus of Jensen, mediated by genus Senegalimassilia and genus Lachnospiraceae UCG010, respectively. Finally, we provided evidence that Clostridium innocuum and genus Ruminococcus2 may partly mediate the causal effect of NOx on altered thickness in the left transverse temporal cortex and area in the right sulcus intermedius primus of Jensen, respectively.

CONCLUSION

This study established a genetic connection between air pollution and brain health, implicating the gut microbiota as a potential mediator in the relationship between air pollution, neurologic disorders, and altered brain structures.

Effects of multiple fluid intake on Urolithiasis by mendelian randomization study

Urolithiasis, a common and recurrent condition, imposes a significant global health burden. This study investigates the causal relationship between various types of fluid intake and urolithiasis using univariable and multivariable Mendelian randomization (MR) approaches. Genetic data for urolithiasis were obtained from the FinnGen Consortium (n = 400,681), while genetic measures for nine fluid types were sourced from meta-analyses of genome-wide association studies (GWAS). The analysis revealed that genetically predicted coffee intake (OR: 0.571, 95% confidence interval (CI): 0.341-0.958, p = 0.034) and ground coffee intake (OR: 0.219, 95% CI: 0.005-0.923, p = 0.038) were protective factors for upper urinary calculi. Additionally, a standard deviation (SD) increase in tea intake was associated with a 53% reduction in risk (OR: 0.473, 95% CI: 0.320-0.700, p < 0.001). Conversely, milk intake (OR: 1.072, 95% CI: 1.018-1.130) and alcohol intakefrequency (OR: 1.304, 95% CI: 1.083-1.570, p = 0.005) increased the risk of upper urinary calculi. These findings highlight the association of tea with reduced risk of urolithiasis, instead for milk and alcohol intake, in formulating prevention strategies for urolithiasis.

Genetic evidence for lifestyle and cardiometabolic factors on the risk of aortic aneurysms: A comprehensive Mendelian randomization study

BACKGROUND AND AIMS

Aortic aneurysm (AAs) is a chronic and severe aortic disease, which is extremely life-threatening due to its delayed diagnosis and a high risk of rupture. In current studies, the association between lifestyle and metabolic factors remains controversial given the complexity of pathogenesis and progression in AAs. Consequently, more reliable and robust evidence should be provided.

METHODS

Genome-wide association studies summary statistics were obtained for 25 factors (6 lifestyle factors and 19 cardiometabolic factors) and AAs. Univariable Mendelian randomization (UVMR) and multivariable MR (MVMR) were used to estimate the causal effect of these factors on AAs. Meanwhile, mediation analysis was applied to assess the mediated effect of lifestyle on the association of cardiometabolic factors with AAs.

RESULTS

Several factors were associated with AA risk, among which triglyceride (TG) (OR = 1.32, 95 % CI = [1.18-1.47], p < 0.001) and high-density lipoprotein cholesterol (HDL-C) (OR = 0.70, 95 % CI = [0.61-0.82], p < 0.001) remain consistently associated with AA risk, with an idependent effect on AAs after adjusting for body mass index (BMI). In addition, TG mediated 15.6 % of BMI effects and 3.7 % of smoking effects on AAs, and HDL-C mediated 5.3 % of the effects of cigarette smoking on AAs.

CONCLUSIONS

TG and HDL-C may be the most reliable factors in the risk of AAs. More scientific management of lifestyle and regular monitoring for cardiometabolic traits may serve as a new and effective direction for the prevention and control of the occurrence of AAs.

Causal relationships between dyslexia and the risk of eight dementias

Observational and genetic studies have reported the relationship between dyslexia and Alzheimer's disease (AD). Until now, the causal effect of dyslexia on AD risk has remained unclear. We conducted a two-sample univariable Mendelian randomization (MR) analysis to determine the causal association between dyslexia and the risk of AD, vascular dementia (VD), Lewy body dementia (LBD), and frontotemporal dementia (FTD) and its four subtypes. First, we selected 42 dyslexia genetic variants from a large-scale genome-wide association studies (GWAS) dataset and extracted their corresponding GWAS summary statistics from AD, VD, LBD, and FTD. Second, we selected four MR methods, including inverse-variance weighted (IVW), weighted median, MR-Egger, and MR-PRESSO. Heterogeneity, horizontal pleiotropy, and leave-one-out sensitivity analysis were then used to evaluate the reliability of all causal estimates. We also conducted multivariable MR (MVMR) and mediation analysis to assess the potential mediating role of cognitive performance (CP) or educational achievement (EA) on the causal association between dyslexia and AD. Two MVMR methods, including MV IVW and MV-Egger, and two-step MR were used to perform the analysis. Using IVW, we found a significant causal association between increased dyslexia and increased risk of AD (OR = 1.15, 95% CI: 1.04-1.28, P = 0.006), but not VD, LBD, FTD, or its four subtypes. MR-PRESSO further supported the statistically significant association between dyslexia and AD (OR = 1.15, 95% CI: 1.05-1.27, P = 0.006). All sensitivity analyses confirmed the reliability of causal estimates. Using MV IVW and mediation analysis, we found no causal relationship between dyslexia and AD after adjusting for CP but not EA, CP mediated the total effect of dyslexia on AD with a proportion of 46.32%. We provide genetic evidence to support a causal effect of increased dyslexia on increased risk of AD, which was largely mediated by CP. Reading activity may be a potential intervention strategy for AD by improving cognitive function.

Genetically predicted small dense low-density lipoprotein cholesterol and ischemic stroke subtype: multivariable Mendelian randomization study

Purpose

Small dense low-density lipoprotein cholesterol (S-LDL-C) has been suggested as a particularly atherogenic factor for ischemic stroke (IS) in observational studies, but the causality regarding the etiological subtype remains unclear. This study aims to explore the causal effects of small dense low-density lipoprotein cholesterol (S-LDL-C), medium (M-LDL-C) and large (L-LDL-C) subfractions on the lifetime risk of ischemic stroke (IS) and main subtypes using two-sample Mendelian randomization (TSMR) design.

Methods

We identified genetic instruments for S-LDL-C, M-LDL-C and L-LDL-C from a genome-wide association study of 115 082 UK Biobank participants. Summary-level data for genetic association of any ischemic stroke (AIS), large artery stroke (LAS), small vessel stroke (SVS) and cardioembolic stroke (CES) were obtained from MEGASTROKE consortium. Accounting for the pleiotropic effects of triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C), we conducted multivariable TSMR analysis.

Results

In univariable TSMR, we found a causal association between genetically predicted S-LDL-C and LAS (IVW-FE: odds ratio (OR) = 1.481, 95% confidence interval (CI): 1.117-1.963, P = 0.006, q = 0.076) but not AIS, SVS or CES. No causal effects were observed for M-LDL-C or L-LDL-C in terms of AIS and IS subtype. In multivariable analysis, the causal association between S-LDL-C and LAS remained significant (IVE-MRE: OR = 1.329, 95% CI: 1.106-1.597, P = 0.002).

Conclusions

Findings supported a causal association between S-LDL-C and LAS. Further studies are warranted to elucidate the underlying mechanism and clinical benefit of targeting S-LDL-C.

Association Between Physical Activity and the Prevalence of Kidney Stones in American Adults: Results From a Multiyear National Survey

OBJECTIVE

To investigate the association between physical activity (PA) and the prevalence of kidney stones.

METHODS

A cross-section study was conducted using data from National Health and Nutrition Examination Survey 2007-2018. PA was evaluated based on the Global Physical Activity Questionnaire. Multivariable logistic regression was performed to elucidate the association between PA (patterns, intensity, duration, and frequency of moderate and vigorous PA) and the prevalence of kidney stones after adjusting for potential confounders. Stratified and interaction analyses were conducted to detect potential effect modifiers. In addition, PA was assessed using metabolic equivalent and physical volume, and followed the regression above. Water intake was obtained from the day 2 dietary recall and was included in the sensitivity analysis.

RESULTS

A total of 34,390 participants were included in the analysis. The multivariable logistic regression revealed that individuals who engaged in moderate PA for 30-60 minutes per day had a significant inverse association with the prevalence of kidney stones in the fully adjusted model (odds ratio=0.804, 95% confidence interval 0.700 to 0.923), while no more significant finding was observed for other PA parameters. Interaction and stratified analyses indicated no covariate modifying the association. The results above were robust in the sensitivity analysis.

CONCLUSION

The duration of moderate PA (30-60 min/d) is inversely associated with the prevalence of kidney stones, while no more significant association was observed between other PA parameters (including patterns, intensity, duration, and frequency of vigorous PA, frequency of moderate PA) and kidney stones.

Metabolic shifts during coffee consumption refresh the immune response: insight from comprehensive multiomics analysis

Coffee, a widely consumed beverage, has shown benefits for human health but lacks sufficient basic and clinical evidence to fully understand its impacts and mechanisms. Here, we conducted a cross-sectional observational study of coffee consumption and a 1-month clinical trial in humans. We found that coffee consumption significantly reshaped the immune system and metabolism, including reduced levels of inflammatory factors and a reduced frequency of senescent T cells. The frequency of senescent T cells and the levels of the senescence-associated secretory phenotype were lower in both long-term coffee consumers and new coffee consumers than in coffee nondrinking subjects, suggesting that coffee has anti-immunosenescence effects. Moreover, coffee consumption downregulated the activities of the The Janus kinase/signal transduction and activator of transcription (JAK/STAT) and mitogen-activated protein kinases (MAPK) signaling pathways and reduced systemic proinflammatory cytokine levels. Mechanistically, coffee-associated metabolites, such as 1-methylxanthine, 3-methylxanthine, paraxanthine, and ceramide, reduced the frequency of senescent CD4+CD57+ T cells in vitro. Finally, in vivo, coffee intake alleviated inflammation and immunosenescence in imiquimod-induced psoriasis-like mice. Our results provide novel evidence of the anti-inflammatory and anti-immunosenescence effects of coffee, suggesting that coffee consumption could be considered a healthy habit.

The Multidisciplinary Approach in the Management of Patients with Kidney Stone Disease-A State-of-the-Art Review

Kidney stone disease has a multifactorial etiology, and evolving dietary habits necessitate continuous updates on the impact of dietary components on lithogenesis. The relationship between diseases influenced by lifestyle, such as obesity and diabetes, and kidney stone risk underscores the need for comprehensive lifestyle analysis. Effective management of kidney stones requires a multidisciplinary approach, involving collaboration among nutritionists, urologists, nephrologists, and other healthcare professionals to address the complex interactions between diet, lifestyle, and individual susceptibility. Personalized dietary therapy, based on each patient's unique biochemical and dietary profile, is essential and necessitates comprehensive nutritional assessments. Accurate dietary intake evaluation is best achieved through seven-day, real-time dietary records. Key factors influencing urinary risk include fluid intake, dietary protein, carbohydrates, oxalate, calcium, and sodium chloride. Personalized interventions, such as customized dietary changes based on gut microbiota, may improve stone prevention and recurrence. Current research suggests individualized guidance on alcohol intake and indicates that tea and coffee consumption might protect against urolithiasis. There is potential evidence linking tobacco use and secondhand smoke to increased kidney stone risk. The effects of vitamins and physical activity on kidney stone risk remain unresolved due to mixed evidence. For diseases influenced by lifestyle, conclusive evidence on targeted interventions for nephrolithiasis prevention is lacking, though preliminary research suggests potential benefits. Management strategies emphasize lifestyle modifications to reduce recurrence risks, support rapid recovery, and identify predisposing conditions, highlighting the importance of these changes despite inconclusive data.

The awareness of renal stones amongst Syrian refugees in northern Jordan

Kidney Stone Disease (KSD) is a globally prevalent condition that can be effectively addressed through proper education. This study investigated the awareness of kidney stones among refugees residing in northern Jordan. A questionnaire was administered to 487 refugees of diverse ages and socioeconomic backgrounds. Notably, 97.3% of the respondents had not attended university, and 30.8% held unskilled jobs. Upon familiarizing themselves with the signs and symptoms of kidney stones, 16.22% of men and 12.32% of women reported experiencing such symptoms. This revealed a significant association, suggesting that men might be more susceptible to developing kidney stones than women due to a lack of medical follow-up and examination for men in the camp. However, 38.77% of individuals were uncertain whether they had kidney stones. Furthermore, 38.96% of refugees were unsure about which healthcare professional to consult when experiencing kidney stone symptoms. This report highlights a serious issue with refugees' knowledge of the symptoms, causes, and treatments for kidney stones. The results indicate that Syrian refugees face challenges in acquiring adequate disease awareness, potentially related to issues of migration and war, including low levels of education, limited income, living in camps, and difficulties accessing treatments when needed. Implementing additional policies is necessary to address these challenges among Syrian refugees; however, further studies are needed to validate these findings.

Carboxymethylated Desmodium styracifolium polysaccharide reduces the risk of calcium oxalate kidney stone formation by inhibiting crystal adhesion and promoting crystal endocytosis

The inhibition of cell surface crystal adhesion and an appropriate increase in crystal endocytosis contribute to the inhibition of kidney stone formation. In this study, we investigated the effects of different degrees of carboxymethylation on these processes. An injury model was established by treating human renal proximal tubular epithelial (HK-2) cells with 98.3 ± 8.1 nm calcium oxalate dihydrate (nanoCOD) crystals. The HK-2 cells were protected with carboxy (-COOH) Desmodium styracifolium polysaccharides at 1.17% (DSP0), 7.45% (CDSP1), 12.2% (CDSP2), and 17.7% (CDSP3). Changes in biochemical indexes and effects on nanoCOD adhesion and endocytosis were detected. The protection of HK-2 cells from nanoCOD-induced oxidative damage by carboxymethylated Desmodium styracifolium polysaccharides (CDSPs) is closely related to the protection of subcellular organelles, such as mitochondria. CDSPs can reduce crystal adhesion on the cell surface and maintain appropriate crystal endocytosis, thereby reducing the risk of kidney stone formation. CDSP2 with moderate -COOH content showed the strongest protective activity among the CDSPs.

Association between tea consumption and risk of kidney stones: results from dose-response meta-analysis of prospective studies and Mendelian randomization analysis

PURPOSE

The association between tea consumption and kidney stones is inconsistent in observational studies. Thus, we performed a dose-response meta-analysis of prospective cohort studies and a two-sample Mendelian randomization (MR) analysis to identify this association.

METHODS

The prospective cohort studies reporting the relationship between tea consumption and kidney stones were searched from PubMed, the Cochrane Library, EMBASE, and Web of Science from inception to December 1, 2023. For MR analysis, the summary-level data for tea consumption and kidney stones were extracted from the UK Biobank available data and the 8th release of the FinnGen consortium, respectively. The inverse-variance weighted (IVW) method was the primary analytical method.

RESULTS

In our dose-response meta-analysis, four prospective cohort studies involving 1,263,008 participants were included, and tea consumption was found to have significant associations with kidney stones (RR: 0.80, 95% CI: 0.73-0.87). We also observed a substantially linear negative relationship between tea consumption and the risk of kidney stones. In MR analysis, the IVW method indicated that tea consumption was inversely associated with kidney stones (OR: 0.71, 95% CI: 0.53-0.94).

CONCLUSION

Our study confirmed a causal relationship between tea consumption and kidney stones, and higher tea consumption may reduce the risk of kidney stones.

Causal effects of gut microbiota on multiple sclerosis: A two-sample Mendelian randomization study

BACKGROUND

Gut microbiota alterations in multiple sclerosis (MS) patients have been reported in observational studies, but whether these associations are causal is unclear.

OBJECTIVE

We performed a Mendelian randomization study (MR) to assess the causal effects of gut microbiota on MS.

METHODS

Independent genetic variants associated with 211 gut microbiota phenotypes were selected as instrumental variables from the largest genome-wide association studies (GWAS) previously published by the MiBioGen study. GWAS data for MS were obtained from the International Multiple Sclerosis Genetics Consortium (IMSGC) for primary analysis and the FinnGen consortium for replication and collaborative analysis. Sensitivity analyses were conducted to evaluate heterogeneity and pleiotropy.

RESULTS

After inverse-variance-weighted and sensitivity analysis filtering, seven gut microbiota with potential causal effects on MS were identified from the IMSGC. Only five metabolites remained significant associations with MS when combined with the FinnGen consortium, including genus Anaerofilum id.2053 (odds ratio [OR] = 1.141, 95% confidence interval [CI]: 1.021-1.276, p = .021), Ruminococcus2 id.11374 (OR = 1.190, 95% CI: 1.007-1.406, p = .042), Ruminococcaceae UCG003 id.11361 (OR = 0.822, 95% CI: 0.688-0.982, p = .031), Ruminiclostridium5 id.11355 (OR = 0.724, 95% CI: 0.585-0.895, p = .003), Anaerotruncus id.2054 (OR = 0.772, 95% CI: 0.634-0.940, p = .010).

CONCLUSION

Our MR analysis reveals a potential causal relationship between gut microbiota and MS, offering promising avenues for advancing mechanistic understanding and clinical investigation of microbiota-mediated MS.

The relationship between coffee-related factors and cortical and hippocampal structure: a triangulation of evidence approach and Mendelian randomization research

Objective

Existing studies have reported sustained changes in the cortical structure of rats due to coffee-related factors, which are speculated to occur in the human body. However, there is a lack of research on this topic. Additionally, previous observational studies have found the impact of diseases on cortical structure and the potential therapeutic effects of coffee on these diseases. Our aim was to study the causal effects of coffee-related factors on the human brain using SNPs (single nucleotide polymorphisms). We will connect these discovered causal effects to the impact of diseases on the brain. Through triangulating evidence, we will reveal the potential active areas of coffee in preventing diseases.

Methods

We utilized GWAS data from multiple cohorts and their databases, selecting instrumental variables for genetic prediction of coffee intake and plasma levels of caffeine and its direct metabolites. We applied these instrumental variables to individual data on cortical thickness and surface area, as well as hippocampal volume, from the ENIGMA and CHARGE consortium for Mendelian randomization analysis (MR). Triangular evidence was obtained by integrating existing evidence through a specified retrieval strategy, calculating the overlap between coffee's effects on brain regions and disease-related brain regions to identify potential regions of action.

Results

The MR analysis yielded 93 positive results for 9 exposures, among which theobromine, a metabolite in the caffeine pathway, was found to be associated with increased hippocampal volume. For cortical structure, theobromine in the caffeine pathway was associated with a decrease in total surface area, while theobromine and caffeine in the pathway were associated with an increase in total thickness. The overlap rate of triangular evidence showed no difference in both overall and subgroup analyses, indicating a high overlap between the effects of coffee on brain regions and disease.

Conclusions

From predicted outcomes from causal effects, coffee intake-related factors may have lasting effects on cortical structure. Additionally, theobromine and theophylline have the greatest impact on certain brain gyri, rather than caffeine. Triangulation evidence indicates that disease and coffee intake-related factors act on the same cortical regions, suggesting the presence of potential shared or antagonistic pathways.

Bowel Habits, Obesity, Intestinal Microbiota and Their Influence on Hemorrhoidal Disease: a Mendelian Randomization Study

Purpose

Hemorrhoids (HEM) are the most common perianal disease, but current observational studies have yielded inconsistent results in investigating the risk factors. Our further exploration of the risk factors will help prevent the disease.

Patients and Methods

We conducted a two-sample bidirectional Mendelian randomization (MR) analysis using publicly available genome-wide association studies (GWAS) statistics from multiple consortia. The inverse-variance weighted (IVW) method was used for the primary analysis. We applied four complementary methods, including weighted median, weighted mode, MR-Egger regression, and Cochrane's Q value, to detect and correct the effects of horizontal pleiotropy.

Results

Genetically determined constipation (OR = 0.97, 95% CI: 0.91-1.03, P = 0.28) and diarrhea (OR = 1.00, 95% CI: 0.99-1.01, P = 0.90) did not have a causal effect on HEM but stool frequency (OR = 1.28, 95% CI: 1.05-1.55, P = 0.01), waist-to-hip ratio adjusted for BMI (OR = 1.11, 95% CI: 1.06-1.64, P = 1.59×10-5), and order Burkholderiales (OR = 1.09, 95% CI = 1.04-1.14, p = 1.63×10-4) had a causal effect on. Furthermore, we found a significant causal effect of constipation on HEM in the reverse MR analysis (OR = 1.21, 95% CI: 1.13-1.28, P = 3.72×10-9). The results of MR-Egger regression, Weighted Median, and Weighted Mode methods were consistent with those of the IVW method. Horizontal pleiotropy was unlikely to distort the causal estimates, as indicated by the sensitivity analysis.

Conclusion

Our MR analysis reveals a causal association between stool frequency and waist-to-hip ratio with HEM, despite variations in results reported by observational studies. Unexpectedly, we found a relationship between the order Burkholderiales in the gut flora and HEM, although the mechanism is unclear.

Mendelian Randomization Reveals: Triglycerides and Sensorineural Hearing Loss

BACKGROUND

Sensorineural hearing loss (SNHL) is a multifactorial disorder with potential links to various physiological systems, including the cardiovascular system via blood lipid levels such as triglycerides (TG). This study investigates the causal relationship between TG levels and SNHL using Mendelian randomization (MR), which offers a method to reduce confounding and reverse causality by using genetic variants as instrumental variables.

METHODS

Utilizing publicly available genome-wide association study (GWAS) data, we performed a two-sample MR analysis. The initial analysis unveiled a causal relationship between TG (GWAS ID: ebi-a-GCST90018975) and SNHL (GWAS ID: finn b-H8_HL_SEN-NAS). Subsequent analysis validated this through MR with a larger sample size for TG (GWAS ID: ieu-b-111) and SNHL. To conduct the MR analysis, we utilized several methods including inverse-variance weighted (IVW), MR Egger, weighted median, and weighted mode. We also employed Cochrane's Q test to identify any heterogeneity in the MR results. To detect horizontal pleiotropy, we conducted the MR-Egger intercept test and MR pleiotropy residual sum and outliers (MR-PRESSO) test. We performed a leave-one-out analysis to assess the sensitivity of this association. Finally, a meta-analysis of the MR results was undertaken.

RESULTS

Our study found a significant positive correlation between TG and SNHL, with OR values of 1.14 (95% CI: 1.07-1.23, p < 0.001) in the IVW analysis and 1.09 (95% CI: 1.03-1.16, p < 0.006) in the replicate analysis. We also found no evidence of horizontal pleiotropy or heterogeneity between the genetic variants (p > 0.05), and a leave-one-out test confirmed the stability and robustness of this association. The meta-analysis combining the initial and replicate analyses showed a significant causal effect with OR values of 1.11 (95% CI: 1.06-1.16, p = 0.01).

CONCLUSION

These findings indicate TG as a risk factor for SNHL, suggesting potential pathways for prevention and intervention in populations at risk. This conclusion underscores the importance of managing TG levels as a strategy to mitigate the risk of developing SNHL.

An exploration of causal relationships between nine neurological diseases and the risk of breast cancer: a Mendelian randomization study

BACKGROUND

Some preceding researches have observed that certain neurological disorders, such as Alzheimer's disease and multiple sclerosis, may affect breast cancer risk. However, whether there are causal relationships between these neurological conditions and breast cancer is inconclusive. This study was designed to explore whether neurological disorders affected the risks of breast cancer overall and of the two subtypes (ER+ and ER-).

METHODS

In the course of this study, genome-wide association study (GWAS) data for nine neurological diseases (Alzheimer's disease, multiple sclerosis, Parkinson's disease, myasthenia gravis, generalized epilepsy, intracerebral haemorrhage, cerebral atherosclerosis, brain glioblastoma, and benign meningeal tumour) were collected from the Complex Trait Genetics lab and the MRC Integrative Epidemiology Unit, and single-nucleotide polymorphisms (SNPs) extensively associated with these neurological ailments had been recognized as instrumental variables (IVs). GWAS data on breast cancer were collected from the Breast Cancer Association Consortium (BCAC). Two-sample Mendelian randomization (MR) analyses as well as multivariable MR analyses were performed to determine whether these SNPs contributed to breast cancer risk. Additionally, the accuracy of the results was evaluated using the false discovery rate (FDR) multiple correction method. Both heterogeneity and pleiotropy were evaluated by analyzing sensitivities.

RESULTS

According to the results of two-sample MR analyses, Alzheimer's disease significantly reduced the risks of overall (OR 0.925, 95% CI [0.871-0.982], P = 0.011) and ER+ (OR 0.912, 95% CI [0.853-0.975], P = 0.007) breast cancer, but there was a negative result in ER- breast cancer. However, after multiple FDR corrections, the effect of Alzheimer's disease on overall breast cancer was not statistically significant. In contrast, multiple sclerosis significantly increased ER+ breast cancer risk (OR 1.007, 95% CI [1.003-1.011], P = 0.001). In addition, the multivariable MR analyses showed that Alzheimer's disease significantly reduced the risk of ER+ breast cancer (IVW: OR 0.929, 95% CI [0.864-0.999], P=0.047; MR-Egger: OR 0.916, 95% CI [0.846-0.992], P=0.031); however, multiple sclerosis significantly increased the risk of ER+ breast cancer (IVW: OR 1.008, 95% CI [1.003-1.012], P=4.35×10-4; MR-Egger: OR 1.008, 95% CI [1.003-1.012], P=5.96×10-4). There were no significant associations between the remainder of the neurological diseases and breast cancer.

CONCLUSIONS

This study found the trends towards a decreased risk of ER+ breast cancer in patients with Alzheimer's disease and an increased risk in patients with multiple sclerosis. However, due to the limitations of Mendelian randomization, we cannot determine whether there are definite causal relationships between neurological diseases and breast cancer risk. For conclusive evidences, more prospective randomized controlled trials will be needed in the future.

Basal metabolic rate and the risk of urolithiasis: a two-sample Mendelian randomization study

OBJECTIVE

Few studies have investigated the impact of basal metabolic rate (BMR) on the development of urolithiasis, and the causal relationship is yet to be established. In this study, a two-sample Mendelian randomization (MR) analysis was utilized to identify the causal relationship between BMR and risk of urolithiasis.

METHOD

Genetic instruments for BMR were drawn from a public genome-wide association study (GWAS). Summary dates on BMR and urolithiasis were obtained from a GWAS meta-analysis with sample sizes of 454,874 and 212,453, respectively. The inverse-variance weighted (IVW) method was provided as the main approach to estimate the causal relationship. The weighted-median method and the MR-Egger method were used as supplements to the IVW method. In addition, we conducted sensitivity analyses, including heterogeneity tests, pleiotropy tests and leave-one-out analysis, to assess the robustness of the outcomes. Furthermore, the funnel plot asymmetry was visually inspected to evaluate possible bias.

RESULTS

The inverse-variance weighted data revealed that genetically predicted BMR significantly decreased the risk of urolithiasis [beta coefficient (beta): - 0.2366, odds ratio (OR): 0.7893, 95% confidence interval (CI) 0.6504-0.9579, p = 0.0166].

CONCLUSIONS

BMR has causal effects on urolithiasis in an MR study, and the risk of urolithiasis in patients with lower levels of BMR is higher.

Association between gut microbiota and onset of type 2 diabetes mellitus: a two-sample Mendelian randomization study

Aim

Mendelian randomization (MR) analysis has been used in the exploration of the role of gut microbiota (GM) in type 2 diabetes mellitus (T2DM); however, it was limited to the genus level. This study herein aims to investigate the relationship of GM, especially at the species level, with T2DM in order to provide some evidence for further exploration of more specific GM taxa and pathway abundance in T2DM.

Methods

This two-sample MR study was based on the summary statistics of GM from the available genome-wide association study (GWAS) meta-analysis conducted by the MiBioGen consortium as well as the Dutch Microbiome Project (DMP), whereas the summary statistics of T2DM were obtained from the FinnGen consortium released data. Inverse variance weighted (IVW), MR-Egger, strength test (F), and weighted median methods were used to examine the causal association between GM and the onset of T2DM. Cochran's Q statistics was employed to quantify the heterogeneity of instrumental variables. Bonferroni's correction was conducted to correct the bias of multiple testing. We also performed reverse causality analysis.

Results

The corrected IVW estimates suggested the increased relative abundance of family Oxalobacteraceae (OR = 1.0704) and genus Oxalobacter (OR = 1.0874), respectively, were associated with higher odds of T2DM, while that of species faecis (OR = 0.9460) had a negative relationship with T2DM. The relationships of class Betaproteobacteria, family Lactobacillaceae, species finegoldii, and species longum with T2DM were also significant according to the IVW results (all P < 0.05).

Conclusions

GM had a potential causal association with T2DM, especially species faecis, finegoldii, and longum. Further studies are still needed to clarify certain results that are contradictory with previous findings.

Blood metabolites mediate the impact of lifestyle factors on the risk of urolithiasis: a multivariate, mediation Mendelian randomization study

Urolithiasis is closely linked to lifestyle factors. However, the causal relationship and underlying mechanisms remain unclear. This study aims to investigate the relationship between lifestyle factors and the onset of urolithiasis and explore potential blood metabolite mediators and their role in mediating this relationship. In this study, we selected single nucleotide polymorphisms (SNPs) as instrumental variables if they exhibited significant associations with our exposures in genome-wide association studies (GWAS) (p < 5.0 × 10-8). Summary data for urolithiasis came from the FinnGen database, including 8597 cases and 333,128 controls. We employed multiple MR analysis methods to assess causal links between genetically predicted lifestyle factors and urolithiasis, as well as the mediating role of blood metabolites. A series of sensitivity and pleiotropy analyses were also conducted. Our results show that cigarettes smoked per day (odds ratio [OR] = 1.159, 95% confidence interval [CI] = 1.004-1.338, p = 0.044) and alcohol intake frequency (OR = 1.286, 95% CI = 1.056-1.565, p = 0.012) were positively associated with increased risk of urolithiasis, while tea intake (OR = 0.473, 95% CI = 0.299-0.784, p = 0.001) was positively associated with reduced risk of urolithiasis. Mediation analysis identifies blood metabolites capable of mediating the causal relationship between cigarettes smoked per day, tea intake and urolithiasis. We have come to the conclusion that blood metabolites serve as potential causal mediators of urolithiasis, underscoring the importance of early lifestyle interventions and metabolite monitoring in the prevention of urolithiasis.

Causal effect of air pollution on the risk of cardiovascular and metabolic diseases and potential mediation by gut microbiota

BACKGROUND

Epidemiological studies have explored the relationship between air pollution and cardiovascular and metabolic diseases (CVMDs). Accumulating evidence has indicated that gut microbiota deeply affects the risk of CVMDs. However, the findings are controversial and the causality remains uncertain. To evaluate whether there is the causal association of four air pollutants with 19 CVMDs and the potential effect of gut microbiota on these relationships.

METHODS

Genetic instruments for particulate matter (PM) with aerodynamic diameter < 2.5 μm (PM2.5), <10 μm (PM10), PM2.5 absorbance, nitrogen oxides (NOx) and 211 gut microbiomes were screened. Univariable Mendelian randomization (UVMR) was used to estimate the causal effect of air pollutants on CVMDs in multiple MR methods. Additionally, to account for the phenotypic correlation among pollutant, the adjusted model was constructed using multivariable Mendelian randomization (MVMR) analysis to strength the reliability of the predicted associations. Finally, gut microbiome was assessed for the mediated effect on the associations of identified pollutants with CVMDs.

RESULTS

Causal relationships between NOx and angina, heart failure and hypercholesterolemia were observed in UVMR. After adjustment for air pollutants in MVMR models, the genetic correlations between PM2.5 and hypertension, type 2 diabetes mellitus (T2DM) and obesity remained significant and robust. In addition, genus-ruminococcaceae-UCG003 mediated 7.8 % of PM2.5-effect on T2DM.

CONCLUSIONS

This study firstly provided the genetic evidence linking air pollution to CVMDs and gut microbiota may mediate the association of PM2.5 with T2DM. Our findings highlight the significance of air quality in CVMDs risks and suggest the potential of modulating intestinal microbiota as novel therapeutic targets between air pollution and CVMDs.

Exploring the causal relationship between gut microbiota and multiple myeloma risk based on Mendelian randomization and biological annotation

Introduction

The microbial genome-wide association studies (mbGWAS) have highlighted significant host-microbiome interactions based on microbiome heritability. However, establishing causal relationships between particular microbiota and multiple myeloma (MM) remains challenging due to limited sample sizes.

Methods

Gut microbiota data from a GWAS with 18,340 participants and MM summary statistics from 456,348 individuals. The inverse variance-weighted (IVW) method was used as the main bidirectional Mendelian randomization (MR) analysis. To assess the robustness of our results, we further performed supplementary analyses, including MR pleiotropy residual sum and outlier (MR-PRESSO) test, MR-Egger, Weighted median, Simple mode, and Weighted mode. Moreover, a backward MR analysis was conducted to investigate the potential for reverse causation. Finally, gene and gene-set-based analyses were then conducted to explore the common biological factors connecting gut microbiota and MM.

Results

We discovered that 10 gut microbial taxa were causally related to MM risk. Among them, family Acidaminococcaceae, Bacteroidales family S24-7, family Porphyromonadaceae, genus Eubacterium ruminantium group, genus Parabacteroides, and genus Turicibacter were positively correlated with MM. Conversely, class Verrucomicrobia, family Verrucomicrobiaceae, genus Akkermansia, and order Verrucomicrobiales were negatively correlated with MM. The heterogeneity test revealed no Heterogeneity. MR-Egger and MR-PRESSO tests showed no significant horizontal pleiotropy. Importantly, leave-one-out analysis confirmed the robustness of MR results. In the backward MR analysis, no statistically significant associations were discovered between MM and 10 gut microbiota taxa. Lastly, we identified novel host-microbiome shared genes (AUTS2, CDK2, ERBB3, IKZF4, PMEL, SUOX, and RAB5B) that are associated with immunoregulation and prognosis in MM through biological annotation.

Discussion

Overall, this study provides evidence supporting a potential causal relationship between gut microbiota and MM risk, while also revealing novel host-microbiome shared genes relevant to MM immunoregulation and clinical prognosis.

The protective effect of caffeine against oxalate-induced epithelial-mesenchymal transition in renal tubular cells via mitochondrial preservation

Mitochondrial dysfunction is one of the key mechanisms for developing chronic kidney disease (CKD). Hyperoxaluria and nephrolithiasis are also associated with mitochondrial dysfunction. Increasing evidence has shown that caffeine, the main bioactive compound in coffee, exerts both anti-fibrotic and anti-lithogenic properties but with unclear mechanisms. Herein, we address the protective effect of caffeine against mitochondrial dysfunction during oxalate-induced epithelial-mesenchymal transition (EMT) in renal cells. Analyses revealed that oxalate successfully induced EMT in MDCK renal cells as evidenced by the increased expression of several EMT-related genes (i.e., Snai1, Fn1 and Acta2). Oxalate also suppressed cellular metabolic activity and intracellular ATP level, but increased reactive oxygen species (ROS). Additionally, oxalate reduced abundance of active mitochondria and induced mitochondrial fragmentation (fission). Furthermore, oxalate decreased mitochondrial biogenesis and content as evidenced by decreased expression of sirtuin-1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), cytochrome c oxidase subunit 4 (COX4), and total mitochondrial proteins. Nonetheless, these oxalate-induced deteriorations in MDCK cells and their mitochondria were successfully hampered by caffeine. Knockdown of Snai1 gene by small interfering RNA (siRNA) completely abolished the effects of oxalate on suppression of cellular metabolic activity, intracellular ATP and abundance of active mitochondria, indicating that these oxalate-induced renal cell deteriorations were mediated through the Snai1 EMT-related gene. These data, at least in part, unveil the anti-fibrotic mechanism of caffeine during oxalate-induced EMT in renal cells by preserving mitochondrial biogenesis and function.

Association of coffee and caffeine consumption with risk and prognosis of endometrial cancer and its subgroups: a Mendelian randomization

Background

Previous studies have not established potential causal associations between coffee and caffeine consumption in endometrial cancer (EC) and its subgroups. Therefore, we used a two-sample MR method to assess the causal association between coffee and caffeine consumption and EC risk. We also evaluated the association between these genetically predicted exposures and EC prognosis.

Materials and methods

This study used 12 and two independent single-nucleotide polymorphisms (SNPs) associated with coffee and caffeine consumption as instrumental variables at a genome-wide significance level of p < 5 × 10-8. The EC Association Consortium (ECAC) performed a genome-wide association study (GWAS) analysis of 12,906 cases and 108,979 controls. FinnGen Consortium performed a GWAS analysis of 1,967 EC cases and 167,189 controls. The primary technique we employed was inverse-variance weighted, followed by the weighted median, MR-Egger regression, and MR robust adjusted profile score methods. We used the MR pleiotropy residual sum, Outlier test, and MR-Egger regression to assess Outlier and pleiotropic variants. We also conducted a sensitivity analysis through the leave-one-out method.

Results

Genetically predicted coffee consumption was not associated with EC and its subgroups in the ECAC, and the association was consistent in the FinnGen consortium. After excluding eight SNPs with confounding factors, the study performed sensitivity analyses, delivering consistent results. We also observed that caffeine consumption was not correlated with EC risk. As confirmed by MR analysis, selected SNPs determined that most do not significantly impact the likelihood of developing EC.

Conclusion

Our study indicated no convincing evidence supports coffee and caffeine consumption causing EC or impacting its prognosis. More studies are needed to validate the results.

Association between COVID-19 and myasthenia gravis (MG): A genetic correlation and Mendelian randomization study

BACKGROUND

Observational studies have suggested an association between coronavirus disease 2019 (COVID-19) and myasthenia gravis (MG). Here, we aimed to estimate the genetic correlation and causal relationship between COVID-19 susceptibility, hospitalization, severity, and MG phenotypes using linkage disequilibrium score regression (LDSC) and Mendelian randomization (MR) approach.

METHODS

Summary statistics of COVID-19 susceptibility, hospitalization, and severity were used as instrumental variables for exposure traits. Large-scale genome-wide association study (GWAS) data for MG were used as outcome traits. The inverse variance weighted approach was used for the main MR analysis, complemented by MR-Egger, weighted median, simple mode, and weighted mode methods. Sensitivity analysis was implemented using Cochran's Q test, MR-PRESSO method, and MR-Egger intercept test.

RESULTS

LDSC analysis did not reveal any genetic correlation among COVID-19 susceptibility, hospitalization, severity, and MG phenotypes, including MG, early-onset MG, and late-onset MG (p > .05). Our MR analysis did not provide evidence supporting a causal effect of COVID-19 susceptibility, hospitalization, or severity on MG phenotypes (p > .05). Extensive sensitivity analysis strengthened the robustness and consistency of the MR estimates.

CONCLUSION

Our study did not find evidence of a genetic correlation or causal relationship among COVID-19 susceptibility, hospitalization, severity, and MG. Future studies with more GWAS data are needed to evaluate the association between COVID-19 phenotypes and MG and its subgroups.

Lifestyle factors, serum parameters, metabolic comorbidities, and the risk of kidney stones: a Mendelian randomization study

Background and objective

The early identification of modifiable risk factors is important for preventing kidney stones but determining causal associations can be difficult with epidemiological data. We aimed to genetically assess the causality between modifiable factors (lifestyle factors, serum parameters, and metabolic comorbidities) and the risk of kidney stones. Additionally, we aimed to explore the causal impact of education on kidney stones and its potential mediating pathways.

Methods

We conducted a two-sample Mendelian randomization (MR) study to explore the causal association between 44 modifiable risk factors and kidney stones. The FinnGen dataset initially explored the causal relationship of risk factors with kidney stones and the UK Biobank dataset was used as the validation set. Then, a meta-analysis was conducted by combining discovery and validation datasets. We used two-step MR to assess potential mediators and their mediation proportions between education and kidney stones.

Results

The combined results indicated that previous exposures may increase the risk of kidney stones, including sedentary behavior, urinary sodium, the urinary sodium/potassium ratio, the urinary sodium/creatinine ratio, serum calcium, 25-hydroxyvitamin D (25OHD), the estimated creatinine-based glomerular filtration rate (eGFRcrea), GFR estimated by serum cystatin C (eGFRcys), body mass index (BMI), waist circumference, type 2 diabetes mellitus (T2DM), fasting insulin, glycated hemoglobin, and hypertension. Coffee intake, plasma caffeine levels, educational attainment, and the urinary potassium/creatinine ratio may decrease the risk of kidney stones. Ranked by mediation proportion, the effect of education on the risk of kidney stones was mediated by five modifiable risk factors, including sedentary behavior (mediation proportion, 25.7%), smoking initiation (10.2%), BMI (8.2%), T2DM (5.8%), and waist circumference (3.2%).

Conclusion

This study provides MR evidence supporting causal associations of many modifiable risk factors with kidney stones. Sedentary lifestyles, obesity, smoking, and T2DM are mediating factors in the causal relationship between educational attainment and kidney stones. Our results suggest more attention should be paid to these modifiable factors to prevent kidney stones.

Caffeine causes cell cycle arrest at G0/G1 and increases of ubiquitinated proteins, ATP and mitochondrial membrane potential in renal cells

Caffeine is a well-known purine alkaloid commonly found in coffee. Several lines of previous and recent evidence have shown that habitual coffee drinking is associated with lower risks for chronic kidney disease (CKD) and nephrolithiasis. However, cellular and molecular mechanisms underlying its renoprotective effects remain largely unknown due to a lack of knowledge on cellular adaptive response to caffeine. This study investigated cellular adaptive response of renal tubular cells to caffeine at the protein level. Cellular proteome of MDCK cells treated with caffeine at a physiologic concentration (100 μM) for 24 h was analyzed comparing with that of untreated cells by label-free quantitative proteomics. From a total of 936 proteins identified, comparative analysis revealed significant changes in levels of 148 proteins induced by caffeine. These significantly altered proteins were involved mainly in proteasome, ribosome, tricarboxylic acid (TCA) (or Krebs) cycle, DNA replication, spliceosome, biosynthesis of amino acid, carbon metabolism, nucleocytoplasmic transport, cell cycle, cytoplasmic translation, translation initiation, and mRNA metabolic process. Functional validation by various assays confirmed that caffeine decreased cell population at G2/M, increased cell population at G0/G1, increased level of ubiquitinated proteins, increased intracellular ATP and enhanced mitochondrial membrane potential in MDCK cells. These data may help unravelling molecular mechanisms underlying the biological effects of caffeine on renal tubular cells at cellular and protein levels.

Irritability and risk of lung cancer: a Mendelian randomization and mediation analysis

BACKGROUND

There is no research to prove the association between irritability and lung cancer, our study performed a Mendelian randomization (MR) approach to elucidate the causal relationship of irritability with lung cancer risk.

METHODS

Genome-wide association studies (GWAS) data of irritability, lung cancer and gastroesophageal reflux disease (GERD) were downloaded from a public database for two-sample MR analysis. Independent single-nucleotide polymorphisms (SNPs) associated with irritability and GERD were selected as instrumental variables (IVs). Inverse variance weighting (IVW) and weighted median method were used to analyze causality.

RESULTS

There is an association between irritability and lung cancer risk (ORIVW = 1.01, 95% CI = [1.00, 1.02], P = 0.018; ORweighted median = 1.01, 95% CI = [1.00, 1.02], P = 0.046), and GERD might account for about 37.5% of the association between irritability and lung cancer.

CONCLUSIONS

This study confirmed the causal effect between irritability and lung cancer through MR analysis, and found that GERD played an essential mediating role in this relationship, which can partly indicate the role of the "inflammation-cancer transformation" process in lung cancer.

Gut microbiome causal impacts on the prognosis of breast cancer: a Mendelian randomization study

BACKGROUND

Growing evidence has shown that gut microbiome composition is associated with breast cancer (BC), but the causality remains unknown. We aimed to investigate the link between BC prognosis and the gut microbiome at various oestrogen receptor (ER) statuses.

METHODS

We performed a genome-wide association study (GWAS) to analyse the gut microbiome of BC patients, the dataset for which was collected by the Breast Cancer Association Consortium (BCAC). The analysis was executed mainly via inverse variance weighting (IVW); the Mendelian randomization (MR) results were verified by heterogeneity tests, sensitivity analysis, and pleiotropy analysis.

RESULTS

Our findings identified nine causal relationships between the gut microbiome and total BC cases, with ten and nine causal relationships between the gut microbiome and ER-negative (ER-) and ER-positive (ER+) BC, respectively. The family Ruminococcaceae and genus Parabacteroides were most apparent among the three categories. Moreover, the genus Desulfovibrio was expressed in ER- BC and total BC, whereas the genera Sellimonas, Adlercreutzia and Rikenellaceae appeared in the relationship between ER + BC and total BC.

CONCLUSION

Our MR inquiry confirmed that the gut microbiota is causally related to BC. This further explains the link between specific bacteria for prognosis of BC at different ER statuses. Considering that potential weak instrument bias impacts the findings and that the results are limited to European females due to data constraints, further validation is crucial.

Causal relationship between particulate matter 2.5 (PM2.5), PM2.5 absorbance, and COVID-19 risk: A two-sample Mendelian randomisation study

Background

Several observational studies reported on the association between particulate matter ≤2.5μm (PM_2.5) and its absorbance with coronavirus (COVID-19), but none use Mendelian randomisation (MR). To strengthen the knowledge on causality, we examined the association of PM_2.5 and its absorbance with COVID-19 risk using MR.

Methods

We selected genome-wide association study (GWAS) integration data from the UK Biobank and IEU Open GWAS Project for two-sample MR analysis. We used inverse variance weighted (IVW) and its multiple random effects and fixed effects alternatives to generally predict the association of PM_2.5 and its absorbance with COVID-19, and six methods (MR Egger, weighted median, simple mode, weighted mode, maximum-likelihood and MR-PRESSO) as complementary analyses.

Results

MR results suggested that PM_2.5 absorbance was associated with COVID-19 infection (odds ratio (OR) = 2.64; 95% confidence interval (CI) = 1.32-5.27, P = 0.006), hospitalisation (OR = 3.52; 95% CI = 1.05-11.75, P = 0.041) and severe respiratory symptoms (OR = 28.74; 95% CI = 4.00-206.32, P = 0.001) in IVW methods. We observed no association between PM_2.5 and COVID-19.

Conclusions

We found a potential causal association of PM_2.5 absorbance with COVID-19 infection, hospitalisation, and severe respiratory symptoms using MR analysis. Prevention and control of air pollution could help delay and halt the negative progression of COVID-19.

Interconnections between urolithiasis and oral health: a cross-sectional and bidirectional Mendelian randomization study

INTRODUCTION

Urolithiasis is one of the most common diseases for urologists and it is a heavy burden for stone formers and society. The theory of the oral-genitourinary axis casts novel light on the pathological process of genitourinary system diseases. Hence, we performed this study to characterize the crosstalk between oral health conditions and urolithiasis to provide evidence for prevention measures and mechanisms of stone formation.

MATERIALS AND METHODS

This population-based cross-sectional study included 86,548 Chinese individuals who had undergone a comprehensive examination in 2017. Urolithiasis was diagnosed depending on the results of ultrasonographic imaging. Logistic models were utilized to characterize the association between oral health conditions and urolithiasis. We further applied bidirectional Mendelian randomization to explore the causality between oral health conditions and urolithiasis.

RESULTS

We observed that presenting caries indicated a negative correlation with the risk for urolithiasis while presenting gingivitis [OR (95% CI), 2.021 (1.866-2.187)] and impacted tooth [OR (95% CI), 1.312 (1.219-1.411)] shown to be positively associated with urolithiasis. Furthermore, we discovered that genetically predicted gingivitis was associated with a higher risk of urolithiasis [OR (95% CI), 1.174 (1.009-1.366)] and causality from urolithiasis to impacted teeth [OR(95% CI), 1.207 (1.027-1.418)] through bidirectional Mendelian randomization.

CONCLUSION

The results cast new light on the risk factor and pathogenesis of kidney stone formation and could provide novel evidence for the oral-genitourinary axis and the systematic inflammatory network. Our findings could also offer suggestions for tailored clinical prevention strategies against stone diseases.