Causal Associations Between Educational Attainment and 14 Urological and Reproductive Health Outcomes: A Mendelian Randomization Study

Urolithiasis Burden in Somalia: Associated Factors and Regional Distribution Among Patients Undergoing CT Scan in Selected Centers in Mogadishu

Background

Urolithiasis is a significant global health burden with varying prevalence rates across different regions. In Somalia, data on the prevalence and risk factors associated with urinary stone disease are limited. This study aimed to investigate the prevalence and associated factors of urolithiasis among patients undergoing CT scans at selected centers in Mogadishu.

Methods

This cross-sectional study was conducted between January and May 2024 at three medical facilities in Mogadishu, Somalia. This study included 211 patients who underwent non-contrast abdominopelvic CT scans. Data were collected using a structured questionnaire that covered sociodemographic characteristics, lifestyle habits, dietary patterns, and clinical data. Statistical analysis was performed using R statistical software version 4.4.0, employing descriptive statistics, bivariate analyses, and logistic regression.

Results

The study revealed a prevalence of 26.07% (95% CI: 20.28-32.54%) for urolithiasis. Significant associations were found with marital status (married individuals showing higher risk, AOR 30.42, 95% CI 3.32-278.58) and education level (higher education showing a protective effect). Dietary factors played a crucial role, with irregular dairy consumption (AOR 37.05, 95% CI 3.44-398.62) and occasional meat consumption (AOR 3.58, 95% CI 1.41-9.08) showing increased risk. Previous diagnosis of urolithiasis (AOR 5.2, 95% CI 1.19-22.81) and history of UTIs (AOR 3.43, 95% CI 1.7-6.95) were significant risk factors.

Conclusion

This study identified a substantial prevalence of urolithiasis in Mogadishu, with significant associations between sociodemographic factors, dietary habits, and medical history. These findings emphasize the need for comprehensive screening programs and targeted interventions, particularly for high-risk individuals.

Causal associations of inflammatory cytokines and urinary stones: a two-sample Mendelian randomization study

Background

Prior research has shown potential changes in cytokine and growth factor levels in patients with urinary stones, but the causal relationship remains uncertain. The purpose of this study was to investigate the causal relationship between cytokine and growth factor levels and urinary tract stones.

Methods

This study used a two-sample Mendelian randomization (MR) with 41 circulating cytokines and growth factors datasets alongside urinary stone disease (USD) data. It employed various analytical methods including inverse variance weighted (IVW) analysis, maximum likelihood estimation, MR-Egger regression, weighted median approach, simple median method, and weighted mode to establish causal relationships. Sensitivity analysis included the MR-Egger regression intercept test and Cochrane's Q statistic.

Results

Using the IVW method, an increase in stem cell growth factor β levels was associated with decreased urinary stone risk [odds ratio (OR) =0.9990; 95% confidence interval (CI): 0.9980-0.9999; P=0.04]. Conversely, an increase in interleukin-18 levels elevated the risk of urinary stones (OR =1.0012; 95% CI: 1.0002-1.0022; P=0.01). Various analytical methods consistently supported these findings.

Conclusions

Our findings suggest a causal and unidirectional relationship between interleukin-18, stem cell growth factors, and USD. This indicates that these cytokines may actively contribute to the development or prevention of USD, offering a new avenue for clinical intervention based on cytokines modulation.

Potential causal association between aspirin use and erectile dysfunction in European population: a Mendelian randomization study

Background

Aspirin, as one of the most commonly used drugs, possesses a broad spectrum of therapeutic applications. Presently, the potential association between aspirin usage and the risk elevation of erectile dysfunction (ED) remains inconclusive. The objective of this study employing two-sample Mendelian randomization (MR) was to clarify the causal impact of aspirin use on the risk of ED.

Methods

This study incorporated two sets of Genome-Wide Association Study (GWAS) summary statistics, one for aspirin use (46,946 cases and 286,635 controls) and another for ED (6,175 cases and 217,630 controls) in individuals of European ancestry. The inverse-variance weighted (IVW) method was employed as the primary approach, supplemented by MR-Egger, weighted median, weighted mode, and simple mode to estimate the causal effect of aspirin usage on the risk of ED development. To assess pleiotropy, the MR-PRESSO global test and MR-Egger regression were used. Cochran's Q test was adopted to check heterogeneity, and the leave-one-out analysis was performed to confirm the robustness and reliability of the results.

Results

The causal association between genetically inferred aspirin use and ED was found by using inverse variance weighted (OR = 20.896, 95% confidence interval = 2.077-2.102E+2, P = 0.010). The sensitivity analysis showed that no pleiotropy and heterogeneity was observed. Furthermore, the leave-one-out analysis demonstrated that the findings were not significantly affected by any instrumental variables.

Conclusion

The results of this study highlighted the significance of aspirin use as a predisposing factor for ED and provided further evidence supporting the causal association between aspirin utilization and ED within European populations.

Specific gut microbiota may increase the risk of erectile dysfunction: a two-sample Mendelian randomization study

Objective

Studies have found that gut microbiota may be associated with the development of erectile dysfunction (ED); however, the exact link between the two remains unclear. This study aimed to elucidate the relationship between the gut microbiota and the risk of ED from a genetic perspective.

Methods

We investigated the relationship between the gut microflora and ED using two-sample Mendelian randomization. GWAS-pooled data for ED were obtained from 223805 participants in Europe. GWAS summary data for ED were obtained from 223805 subjects in Europe and that for the gut microbiota were obtained from 18340 participants in 24 cohorts. We used the inverse-variance weighted (IVW) estimator as the primary method for the preliminary analysis, and the MR-Egger, weighted median (WM), simple model, and weighted model as secondary methods. We used Cochrane's Q-test, to detect heterogeneity, MREgger to detect pleiotropy, and the leave-one-out method to test the stability of the MR results. Ultimately, we genetically predicted a causal relationship between 211 gut microbiota and ED.

Results

A total of 2818 SNPs associated with gut microflora were screened in the ED correlation analysis based on the assumption of instrumental variables. The results of MR analysis showed a causal relationship between the six gut microbes and ED occurrence. The results of the fixed effects IVW method revealed five gut microflora, including Lachnospiraceae (OR, 1.265; P = 0.008), Lachnospiraceae NC2004 group (OR, 1.188; P = 0.019), Oscillibacter (OR, 1.200; P = 0.015), Senegalimassilia (OR, 1.355; P = 0.002), Tyzzerella3 (OR, 1.133; P = 0.022), to be negatively associated with ED. In addition, the IVW method revealed Ruminococcaceae UCG-013 (OR, 0.827; P = 0.049) to be positively associated with ED. Quality control results showed no heterogeneity or horizontal pleiotropy in the MR analysis (P > 0.05).

Conclusions

Six gut microbes were genetically associated with ED; of which, Ruminococcaceae UCG-013 was causally associated with a reduced risk of ED development. Our findings provide a new direction for research on the prevention and treatment of ED; however, the mechanisms and details require further investigation.

The causal relationship between sarcopenic obesity factors and benign prostate hyperplasia

Background

Both benign prostatic hyperplasia (BPH) and sarcopenic obesity (SO) are common conditions among older adult/adults males. The prevalent lifestyle associated with SO is a significant risk factor for the development of BPH. Therefore, we investigated the causal relationship between SO factors and BPH.

Method

The instrumental variables for SO factors were selected using the inverse variance-weighted method, which served as the primary approach for Mendelian randomization analysis to assess the causal effect based on summary data derived from genome-wide association studies of BPH.

Result

The increase in BMR (OR = 1.248; 95% CI = (1.087, 1.432); P = 0.002) and ALM (OR = 1.126; 95% CI = (1.032, 1.228); P = 0.008) was found to be associated with an elevated risk of BPH. However, no genetic causality between fat-free mass distribution, muscle mass distribution, and BPH was observed.

Conclusion

Our findings indicate that a genetic causal association between BMR, ALM and BPH. BMR and ALM are risk factors for BPH. The decrease in BMR and ALM signified the onset and progression of SO, thus SO is a protective factor for BPH.

Effects of heart failure and coronary artery disease on erectile dysfunction: a two-sample mendelian randomization study

BACKGROUND AND AIMS

There are no clear conclusions as to whether heart failure (HF) and coronary heart disease (CAD) increase the risk of erectile dysfunction (ED).In our study, we used Mendelian randomization (MR) analysis to discover a causal relationship between HF, CAD and ED.

METHODS

Single nucleotide polymorphisms (SNPs) associated with HF, CAD and ED were obtained from the MRC IEU Open Genome-Wide Association Study (GWAS) database.After a series of screenings, the remaining SNPs were selected as instrumental variables (IVs) for HF and CAD for MR analysis to assess the relationship between genetically predicted HF or CAD and the pathogenesis of ED.Among them, we used the random-effects inverse variance weighted (IVW) method as the primary analysis method.Finally, Cochran's q-test, funnel plots, MR-Egger regression, Leave-one-out method and MR-PRESSO were used for sensitivity analysis.

RESULTS

In the IVW method, there was no significant causal relationship between genetically predicted HF and CAD and the incidence of ED.(HF: OR = 1.17, 95% CI 0.99-1.39; p = 0.074;CAD: OR = 1.08, 95% CI 0.99-1.17, p = 0.068)。The results of sensitivity analyses supported our conclusion that no horizontal pleiotropism was found.

CONCLUSION

This study did not find a causal relationship between HF or CAD and ED in European populations, which requires further in-depth research.

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.

Causal associations of Sjögren's syndrome with cancers: a two-sample Mendelian randomization study

BACKGROUND

Several observational studies have explored the associations between Sjögren's syndrome (SS) and certain cancers. Nevertheless, the causal relationships remain unclear. Mendelian randomization (MR) method was used to investigate the causality between SS and different types of cancers.

METHODS

We conducted the two-sample Mendelian randomization with the public genome-wide association studies (GWASs) summary statistics in European population to evaluate the causality between SS and nine types of cancers. The sample size varies from 1080 to 372,373. The inverse variance weighted (IVW) method was used to estimate the causal effects. A Bonferroni-corrected threshold of P < 0.0031 was considered significant, and P value between 0.0031 and 0.05 was considered to be suggestive of an association. Sensitivity analysis was performed to validate the causality. Moreover, additional analysis was used to assess the associations between SS and well-accepted risk factors of cancers.

RESULTS

After correcting the heterogeneity and horizontal pleiotropy, the results indicated that patients with SS were significantly associated with an increased risk of lymphomas (odds ratio [OR] = 1.0010, 95% confidence interval [CI]: 1.0005-1.0015, P = 0.0002) and reduced risks of prostate cancer (OR = 0.9972, 95% CI: 0.9960-0.9985, P = 2.45 × 10-5) and endometrial cancer (OR = 0.9414, 95% CI: 0.9158-0.9676, P = 1.65 × 10-5). Suggestive associations were found in liver and bile duct cancer (OR = 0.9999, 95% CI: 0.9997-1.0000, P = 0.0291) and cancer of urinary tract (OR = 0.9996, 95% CI: 0.9992-1.0000, P = 0.0281). No causal effect of SS on other cancer types was detected. Additional MR analysis indicated that causal effects between SS and cancers were not mediated by the well-accepted risk factors of cancers. No evidence of the causal relationship was observed for cancers on SS.

CONCLUSIONS

SS had significant causal relationships with lymphomas, prostate cancer, and endometrial cancer, and suggestive evidence of association was found in liver and bile duct cancer and cancer of urinary tract, indicating that SS may play a vital role in the incidence of these malignancies.

Causal Effects between Gut Microbiome and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Two-Sample Mendelian Randomization Study

Background

Evidence from previous studies have implicated an important association between gut microbiota (GM) and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), but whether there is a definite causal relationship between GM and ME/CFS has not been elucidated.

Method

This study obtained instrumental variables of 211 GM taxa from the Genome Wide Association Study (GWAS), and mendelian randomization (MR) study was carried out to assess the effect of gut microbiota on ME/CFS risk from UK Biobank GWAS (2076 ME/CFS cases and 460,857 controls). Inverse variance weighted (IVW) was the primary method to analyze causality in this study, and a series of sensitivity analyses was performed to validate the robustness of the results.

Results

The inverse variance weighted (IVW) method indicated that genus Paraprevotella (OR:1.001, 95%CI:1.000-1.003, value of p < 0.05) and Ruminococca- ceae_UCG_014 (OR 1.003, 95% CI 1.000 to 1.005, value of p < 0.05) were positively associated with ME/CFS risk. Results from the weighted median method supported genus Paraprevotella (OR 1.003, 95% CI 1.000 to 1.005, value of p < 0.05) as a risk factor for ME/CFS.

Conclusion

This study reveals a causal relationship between genus paraprevotella, genus Ruminococcaceae_UCG_014 and ME/CFS, and our findings provide novel insights for further elucidating the developmental mechanisms mediated by the gut microbiota of ME/CFS.

Effects of major depression and bipolar disorder on erectile dysfunction: a two-sample mendelian randomization study

BACKGROUND AND AIMS

There are currently no clear conclusions about whether major depression (MD) and bipolar disorder (BD) increase the risk of erectile dysfunction (ED). In our study, we used a Mendelian randomization (MR) analysis to discover the causal associations between MD, BD and ED.

METHODS

We got single-nucleotide polymorphisms (SNPs) related to MD, BD and ED from the MRC IEU Open genome-wide association study (GWAS) datasets. After a series of selection, SNPs left were selected as instrumental variables (IVs) of MD and BD for the following MR test to evaluate the relationship of genetically predicted MD or BD with the incidence of ED. Among them, we used the random-effects inverse-variance weighted (IVW) method as the main analysis. Finally, sensitivity analyses were further performed using Cochran's Q test, funnel plots, MR-Egger regression, Leave-one-out method and MR- pleiotropy residual sum and outlier (PRESSO).

RESULTS

Genetically-predicted MD was causally related to the incidence of ED in the IVW methods (odds ratio (OR), 1.53; 95% confidence interval (CI), 1.19-1.96; p = 0.001), while no causal impact of BD on the risk of ED (OR = 0.95, 95% CI 0.87-1.04; p = 0.306). The results of sensitivity analyses supported our conclusion, and no directional pleiotropy were found.

CONCLUSION

The findings of this research found evidence of a causal relationship between MD and ED. However, we did not find a causal relationship between BD and ED in European populations.

Causal effects of hypertension on risk of erectile dysfunction: A two-sample Mendelian randomization study

Background

Erection dysfunction has been associated with hypertension in several epidemiological and observational studies. But the causal association between hypertension and erectile dysfunction requires further investigation.

Methods

A two-sample Mendelian randomization (MR) was conducted to analyze the causal effect of hypertension on risk of erection dysfunction. Large-scale publicly available genome-wide association study data were used to estimate the putative causality between hypertension and risk of erectile dysfunction. A total of 67 independent single nucleotide polymorphisms were selected as instrumental variables. Inverse-variant weighted, maximum likelihood, weighted median, penalized weighted median, and MR-PRESSO approaches were utilized in MR analyses. Heterogeneity test, horizontal pleiotropy test, and leave-one-out method were used to prove the stability of the results.

Results

In total, all P values were less than 0.05, demonstrating a positive causal link between hypertension and risk of erectile dysfunction in multiple MR methods, such as inverse-variant weighted (random and fixed effect) (OR 3.8315, 95% CI 2.3004-6.3817, P = 0.0085), maximum likelihood (OR 3.8877, 95% CI 2.3224-6.5081, P = 0.0085), weighted median (OR 4.9720, 95% CI 2.3645-10.4550, P = 0.0309), penalized weighted median (OR 4.9760, 95% CI 2.3201-10.6721, P = 0.0355), and MR-PRESSO (OR 3.6185, 95% CI 2.2387-5.8488, P = 0.0092). Sensitivity analysis detected no evidence of heterogeneity, pleiotropy, or outlier single nucleotide polymorphisms.

Conclusion

The study revealed a positive causal link between the presence of hypertension and the risk of erectile dysfunction. More attention should be paid during the management of hypertension with the purpose of preventing erectile dysfunction or improving erectile function.

Genetically supported causality between benign prostate hyperplasia and urinary bladder neoplasms: A mendelian randomization study

Background: Observational studies have suggested a possible association between benign prostate hyperplasia (BPH) and bladder cancer (BLCA). However, these studies are prone to errors and limitations or confounding factors, making them unsuitable for assessing the causal relationship between BPH and BLCA. Objective: Two-sample Mendelian randomization (MR) was performed to determine a possible association between genetically predicted BPH and the risk of BLCA. Methods: A two-sample MR analysis was performed utilizing the Integrative Epidemiology Unit genome-wide association (GWAS) database of the Medical Research Council, United Kingdom A series of control steps, including five primary methods, were performed to identify the most suitable instrumental variables (IVs) for MR analysis. Sensitivity analysis was conducted to avoid statistical errors, including heterogeneity and pleiotropic bias. Results: Genetic variants associated with BPH (P < 5 × 10-8) and BLCA (P < 5 × 10-6) were identified as instrumental variables and assessed using GWAS summary data (BPH, 4,670 cases vs. 458,340 controls; BLCA, 1,279 cases vs. 372,016 controls). BPH exhibited a positive effect on the occurrence of BLCA (inverse variance weighted (IVW), odds ratio (OR) = 1.095, 95% confidence interval (CI) = 1.030-1.165, p = 0.003), but there was no causal effect for BLCA on BPH (IVW, OR = 1.092, 95% CI = 0.814-1.465, p = 0.554). Conclusion: Genetically predicted BPH was associated with a higher risk of BLCA in all histological subtypes. In contrast, the evidence was not significant to back the causality of genetically induced BLCA on BPH. These findings indicate that BPH plays a key role in developing BLCA in the European population. Further studies are needed to uncover the underlying mechanisms.

Plasma Proteins as Occupational Hazard Risk Monitors for Populations Working in Harsh Environments: A Mendelian Randomization Study

Harsh work environments can include very cold, hot, dusty, and noisy workplaces, as well as exposure in the workplace with chemicals and other fumes, cigarette smoke, and diesel exhaust. Although working in these harsh environments can have a negative effect on health, there are no effective biomarkers for monitoring health conditions until workers develop disease symptoms. Plasma protein concentrations, which reflect metabolism and immune status, have great potential as biomarkers for various health conditions. Using a Mendelian-randomization (MR) design, this study analyzed the effects of these harsh environments on plasma proteins to identify proteins that can be used as biomarkers of health status. Preliminary analysis using inverse variance weighted (IVW) method with a p-value cutoff of 0.05 showed that workplace environments could affect the concentrations of hundreds of plasma proteins. After filtering for sensitivity via MR-Egger, and Weighted Median MR approaches, 28 plasma proteins altered by workplace environments were identified. Further MR analysis showed that 20 of these plasma proteins, including UNC5D, IGFBP1, SCG3, ST3GAL6, and ST3GAL2 are affected by noisy workplace environments; TFF1, RBM39, ACYP2, STAT3, GRB2, CXCL1, EIF1AD, CSNK1G2, and CRKL that are affected by chemical fumes; ADCYAP1, NRSN1, TMEM132A, and CA10 that are affected by passive smoking; LILRB2, and TENM4 that are affected by diesel exhaust, are associated with the risk of at least one disease. These proteins have the potential to serve as biomarkers to monitor the occupational hazards risk of workers working in corresponding environments. These findings also provide clues to study the biological mechanisms of occupational hazards.