The causal role of gastroesophageal reflux disease in anxiety disorders and depression: A bidirectional Mendelian randomization study

Evidence from a Mendelian randomization study: Delirium's noncausal role in dementia onset

BACKGROUND

Previous observational studies have suggested a possible association between dementia and delirium. However, these findings might be influenced by confounding variables. Thus, our study aimed to investigate the causal relationship between dementia and delirium using a bidirectional Mendelian randomization (MR) analysis.

METHODS

In our investigation, bidirectional MR analysis was conducted by summary statistics from genome-wide association studies (GWAS). This enabled us to evaluate the causal impact of delirium and different types of dementia, such as Alzheimer's dementia (AD), vascular dementia (VaD) and Lewy body dementia (LD).

RESULTS

According to MR analysis, there was a significant positive correlation between delirium risk and AD (odds ratio [OR] = 1.363; 95 % confidence interval [CI], 1.223-1.519; p = 2.140E-08) and LD (OR = 1.403; 95 % CI, 1.151-1.711; p = 8.226E-04). However, the analysis also revealed that there was no causal relationship between VaD (OR = 1.044; 95 % CI = 1.136-1.027; p = 0.316) and the risk of delirium. Additionally, our study does not provide evidence to support a causal correlation between delirium and the risk of developing any form of dementia.

CONCLUSION

The results of the MR analysis suggest a potential causal link between dementia and an increased risk of delirium. Nevertheless, it should be emphasized that the existing evidence does not provide support for a causal connection in the reverse direction, implying that delirium may not play a causative role in the onset of dementia.

Global impact of PM2.5 on cardiovascular disease: Causal evidence and health inequities across region from 1990 to 2021

PM2.5 is an important environmental risk factor for cardiovascular disease (CVD) and poses a threat to global health. This study combines bibliometric analysis, Mendelian randomization (MR), and Global Burden of Disease (GBD) data to comprehensively explore the relationship between PM2.5 exposure and CVD. MR analyses provided strong evidence for causality, reinforcing findings from traditional observational studies. The estimated global burden of PM2.5-related CVD indicated, that there exist significant impacts on the elderly, men, and populations in low and medium socio-demographic index (SDI) areas. This study further found that population growth and aging are the main drivers of this burden with large inequities, although medical advances have mitigated some of the effects. Overall, the opportunity to reduce the burden of CVD remains significant, particularly in medium SDI countries. Projections to 2045 suggested that the absolute burden will increase, while age-standardized rates will decline due to improvements in air quality and health care. These findings emphasized the urgent need for targeted interventions to mitigate the deleterious effects of PM2.5 on global cardiovascular health and to address health inequalities between regions.

Enhancing the robustness of Mendelian randomization studies: lessons from a two-sample analysis of viral infections and colorectal cancer

This Matters Arising article critically examines the study "Genetic susceptibility association between viral infection and colorectal cancer risk: a two-sample Mendelian randomization analysis" by Li et al., highlighting both its contributions and methodological limitations. Their study employed two-sample Mendelian randomization (MR) to explore potential causal links between viral infections and colorectal cancer (CRC), identifying significant associations with infections such as herpes simplex virus and measles. However, several aspects of the methodology warrant scrutiny, including the relaxation of instrumental variable selection thresholds, the handling of potential pleiotropy, and the interpretation of biologically implausible findings. While leveraging advanced MR techniques such as MR-RAPS, cML, ConMix, and dIVW to address challenges like pleiotropy and weak instruments, the study encountered issues related to heterogeneity, insufficient exploration of biological plausibility, and a lack of detailed reporting on instrumental variable (IV) selection and preprocessing. This Matters Arising calls for more rigorous sensitivity analyses, improved transparency in IV selection criteria and harmonization of genome-wide association study (GWAS) datasets, particularly in addressing differences between self-reported and clinically diagnosed infections. Additionally, the Matters Arising article calls for a deeper exploration of biological mechanisms, such as the role of immune modulation and inflammation, to better interpret the observed associations. By addressing these limitations, future MR studies can enhance methodological rigor, improve reproducibility, and provide more robust insights into the causal pathways linking viral infections to CRC risk.

Clinical associations with treatment resistance in depression: An electronic health record study

Treatment resistance is common in major depressive disorder (MDD), yet clinical risk factors are not well understood. Using a discovery-replication design, we conducted phenome-wide association studies (PheWASs) of MDD treatment resistance in two electronic health record (EHR)-linked biobanks. The PheWAS included participants with an MDD diagnosis in the EHR and at least one antidepressant (AD) prescription. Participant lifetime diagnoses were mapped to phecodes. PheWASs were conducted for three treatment resistance outcomes based on AD prescription data: number of unique ADs prescribed, ≥1 and ≥2 CE switches. Of the 180 phecodes significantly associated with these outcomes in the discovery cohort (n = 12,558), 71 replicated (n = 8,206). In addition to identifying known clinical factors for treatment resistance in MDD, the total unique AD prescriptions was associated with additional clinical variables including irritable bowel syndrome, gastroesophageal reflux disease, symptomatic menopause, and spondylosis. We calculated polygenic risk of specific-associated conditions and tested their association with AD outcomes revealing that genetic risk for many of these conditions is also associated with the total unique AD prescriptions. The number of unique ADs prescribed, which is easily assessed in EHRs, provides a more nuanced measure of treatment resistance, and may facilitate future research and clinical application in this area.

The causal role of gastroesophageal reflux disease in endometriosis: a bidirectional Mendelian randomization study

Observational studies have reported an association between gastroesophageal reflux disease (GERD) and endometriosis. We conducted a two-sample and bidirectional Mendelian randomization analysis to determine whether those associations are causal. Two-sample and bidirectional MR analyses were performed using summary statistics from the European Individual Genome-Wide Association Study (GWAS). The inverse variance weighting (IVW) method is used as the main analysis method to evaluate causality. Sensitivity analyses were performed to assess heterogeneity, horizontal versatility, and stability. The results showed no significant causal association between GERD in women with endometriosis in the UK Bank database [ratio (OR) ≈ 0, 95% adjusted interval (CI) 1.0007∼1.0044, P = 0.006] and Finn databases [ratio (OR) = 1.29, 95% adjusted interval (CI) 0.99∼1.67, P = 0.06]. However, when studying the Finn database only for endometriosis, which is confined to the uterus, a significant increase in GERD was limited to the risk of endometriosis in the uterus [ratio (OR) = 1.47, 95% adjusted interval (CI) 1.00∼2.17, P = 0.05]. Sensitivity analysis showed that the results were robust and did not detect multi efficacy or heterogeneity. Meanwhile, reverse MR analysis showed that endometriosis did not increase the risk of GERD. This MR study supports a causal relationship between GERD and an increased risk of endometriosis confined to the uterus. Therefore, patients with gastric esophageal reflux should be treated with gynecological examination to avoid and prevent the development of endometriosis.

Genetic Evidence for Causal Association Between Hypertension and Chronic Pain: A Bidirectional Two-Sample Mendelian Randomization Study

OBJECTIVES

The extent to which the association between hypertension and chronic pain in observational studies is either causally linked or influenced by other shared risk factors has not been substantially addressed. In the present study, Mendelian randomization (MR) was employed to examine the potential causal relationship between hypertension and risk of chronic pain.

METHODS

The study data were derived from the pooled dataset of the genome-wide association study (GWAS), enabling the evaluation of the causal effects of hypertension on various types of chronic pain including chronic headache as well as chest, abdominal, joint, back, limb, and multisite chronic pain. We performed a bidirectional two-sample MR analysis using random effect inverse variance weighting (IVW), MR-Egger, weighted median, and weighted mode, quantified by odds ratio (OR).

RESULTS

Genetically predicted essential hypertension was associated with an increased risk of chronic headache (OR = 1.007, 95% CI: 1.003‒‍1.011, P = 0.002) and limb pain (OR = 1.219, 95% CI: 1.033‍‒‍1.439, P = 0.019). No potential causal associations were identified between chronic pain and essential hypertension in the reverse direction MR ( P > 0.05). In addition, there was no potential causal association between secondary hypertension and chronic pain (P > 0.05).

CONCLUSIONS

This study provided genetic evidence that a unidirectional causal relationship exists between essential hypertension and the increased risks of chronic headache and limb pain, and no causal relationship was found between secondary hypertension and chronic pain. These findings offer theoretical underpinnings for future research on managing hypertension and chronic pain.

Plasma proteometabolome in lung cancer: exploring biomarkers through bidirectional Mendelian randomization and colocalization analysis

Unlike other cancers with widespread screening (breast, colorectal, cervical, prostate, and skin), lung nodule biopsies for positive screenings have higher morbidity with clinical complications. Development of non-invasive diagnostic biomarkers could thereby significantly enhance lung cancer management for at-risk patients. Here, we leverage Mendelian Randomization (MR) to investigate the plasma proteome and metabolome for potential biomarkers relevant to lung cancer. Utilizing bidirectional MR and co-localization analyses, we identify novel associations, highlighting inverse relationships between plasma proteins SFTPB and KDELC2 in lung adenocarcinoma (LUAD) and positive associations of TCL1A with lung squamous cell carcinoma (LUSC) and CNTN1 with small cell lung cancer (SCLC). Additionally, our work reveals significant negative correlations between metabolites such as theobromine and paraxanthine, along with paraxanthine-related ratios, in both LUAD and LUSC. Conversely, positive correlations are found in caffeine/paraxanthine and arachidonate (20:4n6)/paraxanthine ratios with these cancer types. Through single-cell sequencing data of normal lung tissue, we further explore the role of lung tissue-specific protein SFTPB in carcinogenesis. These findings offer new insights into lung cancer etiology, potentially guiding the development of diagnostic biomarkers and therapeutic approaches.

Prevalence and risk factors of gastroesophageal reflux disease in Iran: A cross-sectional analysis from the PERSIAN cohort

BACKGROUND

This study assessed the prevalence of gastroesophageal reflux disease (GERD) in a general adult population in Iran. The association between GERD and various factors was also evaluated.

METHODS

We performed a cross-sectional study on 163,018 individuals aged over 35 who were enrolled in the PERSIAN cohort. GERD was defined as the occurrence of heartburn and/or regurgitation symptoms at least several days a month. Survey design analysis for pooled data was performed and multiple regression analysis was conducted to determine the independent risk factors for GERD.

RESULTS

The prevalence of GERD in our study was estimated at 21.86% (95% confidence interval:17.4%-36.4%). The mean age of the participants was 49.84 years±9.25 (35-70) and 44.75% of the participants were male. Symptoms of heartburn and regurgitation were reported in 18.65% (n: 29,170) and 6.06% (n: 9,717) of participants, respectively. In the multivariate analysis, several factors were found to be associated with a higher prevalence of GERD: female sex, age >50, current smoking, opium use, weekly consumption of fried foods, frequent consumption of hot tea, less than 6 hours of sleep per night, psychiatric disorders, usage of NSAIDs, and poor oral hygiene, were associated with a higher prevalence of GERD. Conversely, higher education levels and average physical activity were found to be less commonly associated with GERD.

CONCLUSION

We found a relatively high prevalence of GERD (21.86%) in this population-based study in Iran. By identifying modifiable risk factors, this research offers opportunities for targeted interventions and lifestyle modifications to reduce the burden of GERD.

Migraine and gastroesophageal reflux disease: Disentangling the complex connection with depression as a mediator

OBJECTIVE

Gastroesophageal reflux disease (GERD) and migraine are public health concerns worldwide. No observational study has conclusively elucidated the causal relationship between these two conditions. We employed Mendelian randomization (MR) methods to explore the potential causal links between GERD and migraine.

METHODS

Genome-wide association studies were subjected to MR to infer the causality between GERD and migraine. Bidirectional two-sample MR was performed to establish causal relationships. Multivariable MR analysis was conducted to adjust potential confounding factors, and mediation MR analysis was utilized to assess the role of depression between GERD and migraine as a mediator. We primarily utilized the inverse variance weighted method (IVW) and sensitivity analysis methods, including MR-Egger, weighted median, and leave-one-out methods. We assessed heterogeneity and pleiotropy to ensure the reliability of the results.

RESULTS

Bidirectional two-sample MR revealed a positive causal effect of GERD on migraine (IVW: OR = 1.49, 95% CI: 1.34-1.66, p = 3.70E-13). Migraine did not increase the risk of GERD (IVW: OR = 1.07, 95% CI: 0.98-1.17, p = 0.1139). Multivariable MR indicated that the positive causal effect of GERD on migraine remained after adjustment for factors, such as smoking, alcohol consumption, obesity, type 2 diabetes, and depression. Mediation MR revealed that depression mediated 28.72% of GERD's effect on migraine. MR analysis was supported by all sensitivity analyses and was replicated and validated in another independent dataset on migraine.

CONCLUSION

Our findings elucidate the positive causal effect of GERD on migraine and underscores the mediating role of depression in increasing the risk of migraine due to GERD. Effective control of GERD, particularly interventions targeting depression, may aid in preventing the occurrence of migraine. Future research should delve deeper into the specific pathophysiological mechanisms through which GERD affects migraine risk, facilitating the development of more effective drug targets or disease management strategies.

Bidirectional causal relational between frailty and mental illness: a two-sample Mendelian randomization study

Background

Frailty has been associated with mental illness (MI) observational studies, but the causal relationship between these factors remains uncertain. We aimed to assess the bidirectional causality between frailty and MI by two-sample Mendelian randomization (MR) analyses.

Methods

To investigate the causal relationship among them, summary statistics of frailty index (FI) and six types of MI: anxiety, depression, affective disorder, mania, schizophrenia, and obsessive-compulsive disorder (OCD) were included in this MR study. This MR analysis was performed using inverse variance weighting (IVW), MR-Egger regression, and weighted median. The stability of the results was evaluated using Cochran's Q test, MR-Egger intercept test, Funnel Plots, and leave-one-out analysis.

Results

Genetic predisposition to FI was significantly associated with increased anxiety (odds ratio [OR] = 1.62, 95% confidence interval [CI] 1.13-2.33, P = 8.18E-03), depression (OR = 1.88, 95% CI 1.30-2.71, P = 8.21E-04), affective disorder (OR = 1.70, 95% CI 1.28-2.27, P = 2.57E-04). However, our study findings do not demonstrate a causal relationship between FI and mania (OR = 1.02, 95% CI 0.99-1.06, P = 2.20E-01), schizophrenia (OR = 1.02, 95% CI 0.07-0.86, P = 9.28E-01). In particular, although the IVW results suggest a potential causal relationship between FI and OCD (OR = 0.64, 95% CI 0.07-0.86, P = 2.85E-02), the directions obtained from the three methods we employed ultimately show inconsistency. Therefore, the result must be interpreted with caution. The results of the reverse MR analysis indicated a statistically significant and causal relationship between anxiety (OR = 1.06, 95% CI 1.01-1.11, P = 2.00E-02), depression (OR = 1.14, 95% CI 1.04-1.26, P = 7.99E-03), affective disorder (OR = 1.15, 95% CI 1.09-1.21, P = 3.39E-07), and schizophrenia (OR = 1.02, 95% CI 1.01-1.04, P = 1.70E-03) with FI. However, our findings do not provide support for a link between mania (OR = 1.46, 95% CI 0.79-2.72, P = 2.27E-01), OCD (OR = 1.01, 95% CI 1.00-1.02, P = 2.11E-01) and an increased risk of FI.

Conclusion

The MR results suggest a potential bidirectional causal relationship between FI and anxiety, depression, and affective disorder. Schizophrenia was found to be associated with a higher risk of FI. The evidence was insufficient to support a causal relationship between Fl and other Ml. These findings offer new insights into the development of effective management strategies for frailty and MI.

Absence of causative genetic association between Helicobacter pylori infection and glaucoma: a bidirectional two-sample mendelian randomization study

Background: While clinical research has indicated a potential link between Helicobacter pylori infection and the onset of glaucoma, the causality of this association remains uncertain due to the susceptibility of observational studies to confounding factors and reverse causation. Methods: A comprehensive two-sample bidirectional Mendelian randomization (MR) analysis was conducted to assess the causal connection between H. pylori infection and glaucoma. Glaucoma was categorized into primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and pseudo-exfoliation glaucoma (PEG). Various methods, including inverse variance weighted, MR-Egger regression, weighted median, and mode-based estimator, were employed for effect estimation and pleiotropy testing. To enhance result robustness, a sensitivity analysis was performed by excluding proxy single nucleotide polymorphisms. Results: Genetic predisposition for H. pylori infection has no causal effect on glaucoma: (OR 1.00; 95% CI 0.95-1.06, p = 0.980), (OR 0.97; 95% CI 0.86-1.09, p = 0.550), and (OR 0.99; 95% CI 0.90-1.08, p = 0.766) with POAG, NTG, and PEG, respectively. An inverse MR showed no causal effect of POAG, NTG, and PEG on H. pylori infection (OR 1.01; 95% CI 0.97-1.05, p = 0.693), (OR 1.00; 95% CI 0.98-1.03, p = 0.804), and (OR 0.99; 95% CI 0.96-1.01, p = 0.363), respectively. Heterogeneity (p > 0.05) and pleiotropy (p > 0.05) analysis confirmed the robustness of MR results. Conclusion: These results indicated that there was no genetic evidence for a causal link between H. pylori and glaucoma, suggesting that the eradication or prevention of H. pylori infection might not benefit glaucoma and vice versa.

A comprehensive Mendelian randomization study highlights the relationship between psychiatric disorders and non-tumor gastrointestinal diseases

Objective

Previous observational studies revealed the potential correlation between psychiatric disorders (PDs) and non-tumor gastrointestinal diseases (NTGDs). However, their causation remains unclear.

Methods

We explored the causal relationship between PDs and NTGDs through bidirectional two-sample Mendelian randomization (MR) study. Large-scale genome-wide association study (GWAS) summary statistics and bidirectional two-sample MR study were used to assess the causality between PDs and NTGDs. Multiple sensitivity analyses were used to identify the robustness of our results.

Results

We found that major depression was causally associated with increased risk of gastric ulcer (OR: 1.812, 95% CI: 1.320-2.487, p < 0.001) and irritable bowel syndrome (OR: 1.645, 95% CI: 1.291-2.097, p < 0.001). Meanwhile, genetically predicted gastroesophageal reflux disease contributed to the increased risk of anxiety disorders (OR: 1.425, 95% CI: 1.295-1.568, p < 0.001), and ulcerative colitis was related to increased risk of attention deficit/hyperactivity disorder (OR: 1.042, 95% CI: 1.008-1.078, p = 0.0157).

Conclusion

Our study provided MR evidence to support the close causality and identify the specific direction between eight PDs and eight common NTGDs. Experimental studies to further examine the causality, underlying mechanism, and therapeutic potential of PDs and NTGDs are required.

Gastroesophageal reflux disease with 6 neurodegenerative and psychiatric disorders: Genetic correlations, causality, and potential molecular mechanisms

The comorbidities between gastroesophageal reflux disease (GERD) and various neurodegenerative and psychiatric disorders have been widely reported. However, the genetic correlations, causal relationships, and underlying mechanisms linking GERD to these disorders remain largely unknown. Here, we conducted a bidirectional Mendelian randomization (MR) analysis to determine the causality between GERD and 6 neurodegenerative and psychiatric disorders. Sensitivity analyses and multivariable MR were performed to test the robustness of our findings. Linkage disequilibrium score regression was used to assess the genetic correlation between these diseases as affected by heredity. Multiple bioinformatics tools combining two machine learning algorithms were applied to further investigate the potential mechanisms underlying these diseases. We found that genetically predicted GERD significantly increased the risk of Alzheimer's disease, major depressive disorder, and anxiety disorders. There might be a bidirectional relationship between GERD and insomnia. GERD has varying degrees of genetic correlations with AD, ALS, anxiety disorders, insomnia, and depressive disorder. Bioinformatics analyses revealed the hub shared genes and the common pathways between GERD and 6 neurodegenerative and psychiatric disorders. Our findings demonstrated the complex nature of the genetic architecture across these diseases and clarified their causality, highlighting that treatments for the cure or remission of GERD may serve as potential strategies for preventing and managing neurodegenerative and psychiatric disorders.

Identifying causal relationships between gastroesophageal reflux and extraesophageal diseases: A Mendelian randomization study

Traditional observational and in vivo studies have suggested an etiological link between gastroesophageal reflux disease (GERD) and the development of extraesophageal diseases (EEDs), such as noncardiac chest pain. However, evidence demonstrating potential causal relationships is lacking. This study evaluated the potential causal relationship between GERD and EEDs, including throat and chest pain, asthma, bronchitis, chronic rhinitis, nasopharyngitis and pharyngitis, gingivitis and periodontal disease, cough, using multiple Mendelian randomization (MR) methods, and sensitivity analysis was performed. The Mendelian randomization Pleiotropy RESidual Sum and Outlier and PhenoScanner tools were used to further check for heterogeneous results and remove outliers. MR with inverse-variance weighted (IVW) showed a significant causal relationship between GERD and EEDs after Bonferroni correction. IVW results indicated that GERD increased the risk of chronic rhinitis, nasopharyngitis and pharyngitis (odds ratio [OR] = 1.482, 95% confidence interval [CI] = 1.267-1.734, P < .001], gingivitis and periodontal disease (OR = 1.166, 95% CI = 1.046-1.190, P = .001), throat and chest pain (OR = 1.585, 95% CI = 1.455-1.726, P < .001), asthma (OR = 1.539, 95% CI = 1.379-1.717, P < .001), and bronchitis (OR = 1.249, 95% CI = 1.168-1.335, P < .001). Sensitivity analysis did not detect pleiotropy. Leave-one-out analysis shows that MR results were not affected by individual single nucleotide polymorphisms. The funnel plot considers the genetic instrumental variables to be almost symmetrically distributed. This MR supports a causal relationship among GERD and EEDs. Precise moderation based on causality and active promotion of collaboration among multidisciplinary physicians ensure high-quality diagnostic and treatment recommendations and maximize patient benefit.

Risk factors for gastroesophageal reflux disease: a population-based study

BACKGROUND

Gastroesophageal reflux disease (GERD) in the long term reduces the quality of life, leading to digestive diseases. The present study aims to determine the risk factors for GERD.

METHOD

This study was conducted on 9,631 adults aged 35-65 years. The demographic characteristics, behavioral habits, nutritional intake, physical activity, anthropometric indices, and GERD data were extracted from the databank related to the Ravansar non-communicable diseases (RaNCD). Statistical analysis was performed using logistic regression models.

RESULTS

The prevalence of GERD was 10.99% (n = 1,058). The GERD was higher among older age and women. After adjusting for age and sex, the odds of GERD among current smokers was 23% higher than non-smokers. Drinking increased odds of GERD (OR: 1.51; 95% CI: 1.13, 1.99). The odds of GERD among depressed individuals were 46% higher than non-depressed. In addition, a significant relationship was observed between the high intake of sweets and desserts with increased GERD (OR: 1.02, 95% CI: 1.01, 1.03). Further, high intake of fiber (OR: 0.98, 95% CI: 0.97, 0.99) and dairy (OR: 0.99, 95% CI: 0.98, 0.99) was related to reducing the odds of GERD. Furthermore, a significant relationship was reported between the waist hip ratio (WHR) and visceral fat area (VFA) with increased odds of GERD. Finally, the physical activity level was inversely related to GERD.

CONCLUSION

Based on the results, smoking, alcohol, inactivity, high intake of sweets and desserts, low intake of fiber, depression, visceral fat, and obesity are considered as risk factors for GERD. Modifying lifestyle and behavioral habits prevent GERD.

Upper Airway-Related Symptoms According to Mental Illness and Sleep Disorders among Workers Employed by a Large Non-Profit Organization in the Mountain West Region of the United States

The relationships between selected upper airway-related symptoms (speech disturbances, voice disorders, cough, and breathing abnormalities) and mental illness and sleep disorders have been previously demonstrated. However, these relationships have not been compared in a single study with consideration of potential confounding variables. The current research incorporates a descriptive study design of medical claims data for employees (~21,362 per year 2017-2021) with corporate insurance to evaluate the strength of these relationships, adjusting for demographic variables and other important confounders. The upper airway-related symptoms are each significantly and positively associated with several mental illnesses and sleep disorders, after adjusting for demographic and other potential confounders. The rate of any mental illness is 138% (95% CI 93-195%) higher for speech disturbances, 55% (95% CI 28-88%) higher for voice disorders, 28% (95% CI 22-34%) higher for cough, and 58% (95% CI 50-66%) higher for breathing abnormalities, after adjustment for the confounding variables. Confounding had significant effects on the rate ratios involving cough and breathing abnormalities. The rate of any sleep disorder is 78% (95% CI 34-136%) higher for speech disturbances, 52% (95% CI 21-89%) higher for voice disorders, 34% (95% CI 27-41%) higher for cough, and 172% (95% CI 161-184%) higher for breathing abnormalities, after adjustment for the confounding variables. Confounding had significant effects on each of the upper airway-related symptoms. Rates of mental illness and sleep disorders are positively associated with the number of claims filed for each of the upper airway-related symptoms. The comorbid nature of these conditions should guide clinicians in providing more effective treatment plans that ultimately yield the best outcome for patients.

Association Between Anxiety/Depression and Gastroesophageal Reflux: A Systematic Review and Meta-Analysis

INTRODUCTION

An association between gastroesophageal reflux disease (GERD) and common psychiatric conditions, most notably anxiety and depression, has been reported. However, the magnitude of this association is poorly understood. Therefore, we aimed to systematically assess this issue.

METHODS

We comprehensively searched multiple bibliographic databases (Embase, PubMed, Scopus, and Web of Science) from inception to May 15, 2023. We retrieved observational studies that reported the prevalence of anxiety and/or depressive symptoms diagnosed by validated questionnaires in ≥100 adults (aged 18 years or older) with GERD. We also included cohort studies that explored the risk of incident GERD in subjects with anxiety/depression vice versa scenario. Finally, we included Mendelian randomization studies that assessed the cause-and-effect relationship between anxiety/depression and GERD. The extracted data were combined using a random-effects model.

RESULTS

In total, 36 eligible studies were included. The pooled prevalences of anxiety and depressive symptoms were 34.4% (95% confidence interval [CI] 24.7-44.2; I2 = 99.4%) and 24.2% (95% CI 19.9-28.5; I2 = 98.8%) in subjects with GERD based on 30 studies, respectively. Both anxiety and depressive symptoms were more common in subjects with GERD compared with those in healthy controls (odds ratio = 4.46 [95% CI 1.94-10.25] and odds ratio = 2.56 [95% CI 1.11-5.87], respectively). According to 3 cohort studies, subjects with GERD were at an increased risk of developing anxiety/depression and vice versa. Finally, 3 Mendelian randomization studies showed that genetic liability to these mood disorders is linked to an increased risk of developing GERD and vice versa.

DISCUSSION

Up to 1 in 3 subjects with GERD experience anxiety and depression. There is likely a bidirectional causal relationship between anxiety/depression and GERD.

Causal association of gastroesophageal reflux disease with obstructive sleep apnea and sleep-related phenotypes: a bidirectional two-sample Mendelian randomization study

Background

The interactions and associations between obstructive sleep apnea (OSA), sleep-related phenotypes (SRPs), and gastroesophageal reflux disease (GERD) are complex, thus it is hard to explore the effect and direction of causalities.

Study objectives

A bidirectional Mendelian randomization (MR) study was performed to explore causal associations of GERD with OSA and SRPs (including insomnia, morningness, sleep duration, ease of getting up, daytime napping, daytime dozing, and snoring).

Methods

First, we gathered summary statistics from publicly available databases. Subsequently, we identified single-nucleotide polymorphisms without strong linkage (r2 ≤ 0.001) by referencing relevant genome-wide association studies that met genome-wide significance criteria. Our primary analysis relied on inverse variance weighted to estimate the causal relationship. To ensure the validity of our findings, we also conducted several sensitivity analyses. These included MR Pleiotropy RESidual Sum and Outlier to detect and correct for potential pleiotropic effects, MR-Egger to assess directional pleiotropy, and weighted median analysis to further evaluate heterogeneity and pleiotropy. For the initial MR analysis, when causality was indicated by the results, instrumental variables that were significantly linked to the aforementioned confounding factors were removed. We will re-analyze the data after excluding outcome-related single nucleotide polymorphisms to confirm that the results are still consistent with the previous results.

Results

GERD was found to increase the risk of OSA (OR = 1.53, 95% CI = 1.37-1.70, p = 5.3 × 10-15), insomnia (OR = 1.14, 95% CI = 1.10-1.19, p = 1.3 × 10-10), snoring (OR = 1.09, 95% CI = 1.04-1.13, p = 6.3 × 10-5) and less sleep duration (OR = 0.94, 95% CI = 0.91-0.97, p = 3.7 × 10-4). According to the reverse-direction analysis, there is an elevated risk of GERD associated with OSA (OR = 1.07, 95% CI = 1.02-1.12, p = 0.005), insomnia (OR = 1.95, 95% CI = 1.60-2.37, p = 1.92 × 10-11) and snoring (OR = 1.74, 95% CI = 1.37-2.21, p = 4.4 × 10-6).

Conclusion

Genetic susceptibility to GERD can elevate the likelihood of experiencing insomnia, snoring, and OSA, in addition to diminishing sleep duration. Conversely, a reverse MR analysis indicates that ameliorating any one of insomnia, snoring, or OSA can mitigate the risk of developing GERD.

The relationship between COVID-19, depressive disorder, and anxiety: a bidirectional Mendelian randomization study

Background

Previous clinical studies have found that negative mental states such as depression and anxiety are closely related to COVID-19 infection. We used Mendelian randomization (MR) to explore the relationship between depression, anxiety, and COVID-19 infection.

Methods

Our data were based on publicly available GWAS databases. The COVID-19 samples were obtained from the COVID-19 Host Genetics Initiative (HGI). The depression samples were obtained from the Psychiatric Genomics Consortium (PGC). The anxiety samples were derived from the Finngen database. We used inverse-variance weighting (IVW) as the primary analysis method, with weighted median, MR Egger, and multivariate MRI adjustment.

Results

There was no causal effect of different COVID-19 infection statuses on depression and anxiety as determined by MR analysis. In addition, in the reverse MR analysis, we found a significant causal effect of anxiety on severe symptoms after COVID-19 infection. The results of the MR Egger regression, weighted median, and weighted mode methods were consistent with the IVW method. Based on sensitivity analyses, horizontal pleiotropy was unlikely to influence the final results.

Conclusion

Our findings indicate that anxiety is a risk factor for severe symptoms following COVID-19 infection. However, the mechanism of interaction between the two needs further investigation.

Major depressive disorder plays a vital role in the pathway from gastroesophageal reflux disease to chronic obstructive pulmonary disease: a Mendelian randomization study

Background: Observational studies have shown a bidirectional association between chronic obstructive pulmonary disease (COPD) and gastroesophageal reflux disease (GERD), but it is not clear whether this association is causal. In our previous study, we found that depression was a hot topic of research in the association between COPD and GERD. Is major depressive disorder (MDD) a mediator of the association between COPD and GERD? Here, we evaluated the causal association between COPD, MDD, and GERD using Mendelian randomization (MR) study. Methods: Based on the FinnGen, United Kingdom Biobank, and Psychiatric Genomics Consortium (PGC) databases, we obtained genome-wide association study (GWAS) summary statistics for the three phenotypes from 315,123 European participants (22,867 GERD cases and 292,256 controls), 462,933 European participants (1,605 COPD cases and 461,328 controls), and 173,005 European participants (59,851 MDD cases and 113,154 controls), respectively. To obtain more instrumental variables to reduce bias, we extracted relevant single-nucleotide polymorphisms (SNPs) for the three phenotypes from published meta-analysis studies. Bidirectional MR and expression quantitative trait loci (eQTL)-MR were performed using the inverse variance weighting method to assess the causal association between GERD, MDD, and COPD. Results: There was no evidence of a causal effect between GERD and COPD in the bidirectional MR analysis [forward MR for GERD on COPD: odds ratios (OR) = 1.001, p = 0.270; reverse MR for COPD on GERD: OR = 1.021, p = 0.303]. The causal effect between GERD and MDD appeared to be bidirectional (forward MR for GERD on MDD: OR = 1.309, p = 0.006; reverse MR for MDD on GERD: OR = 1.530, p < 0.001), while the causal effect between MDD and COPD was unidirectional (forward MR for MDD on COPD: OR = 1.004, p < 0.001; reverse MR for COPD on MDD: OR = 1.002, p = 0.925). MDD mediated the effect of GERD on COPD in a unidirectional manner (OR = 1.001). The results of the eQTL-MR were consistent with those of the bidirectional MR. Conclusion: MDD appears to play a vital role in the effect of GERD on COPD. However, we have no evidence of a direct causal association between GERD and COPD. There is a bidirectional causal association between MDD and GERD, which may accelerate the progression from GERD to COPD.