Causal relationship between gastro-esophageal reflux disease and risk of lung cancer: insights from multivariable Mendelian randomization and mediation analysis

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.

Type 2 diabetes, glycaemic traits, structural brain capacity and cognitive function: A Mendelian randomization analysis

AIM

To estimate the causal associations of type 2 diabetes and glycaemic traits with cognitive function, and to determine the potential mediating role of various brain imaging-derived phenotypes (IDPs) using Mendelian randomization (MR) analysis.

METHODS

Using publicly available summary data, we performed a series of univariable and multivariable MR analysis to infer causality. Two-step MR analysis was then conducted in turn to evaluate the potential mediating role of each brain IDP.

RESULTS

There was no evidence of causal associations between type 2 diabetes and cognitive function outcomes. Each 1-SD unit higher genetically predicted fasting proinsulin was associated with worse cognitive performance, as evidenced by both univariable (beta: -0.022; 95% confidence interval [CI] -0.038, -0.007) and multivariable MR analysis (beta: -0.027; 95% CI -0.048, -0.005). In addition, the univariable MR analysis identified several causal associations between fasting proinsulin and brain IDPs, and between brain IDPs and cognitive performance. The inverse association of genetically predicted fasting proinsulin with cognitive performance did not attenuate after adjusting for each of the brain IDPs in multivariable MR analysis.

CONCLUSIONS

The present MR study provided credible evidence for the causal association between genetically predicted fasting proinsulin and cognitive function, informing a potential diagnosis and intervention target for patients with cognitive impairment. No significant brain IDP included in this study was identified as lying on the causal pathway from fasting proinsulin to cognitive performance. Future research involving more specific and granular brain IDP or other brain process is warranted to explore the potential biological mechanism underlying the association.

The causal effect of exposure to air pollution on risk of adverse pregnancy outcomes: A two-sample Mendelian randomisation study

BACKGROUND

Epidemiological studies have examined the relation between air pollution (NOx, NO2, PM2.5, PM2.5-10, and PM10) and adverse pregnancy outcomes (APOs). There's increasing evidence that air pollution increases the risk of APOs. However, the results of these studies are controversial, and the causal relation remains uncertain. We aimed to assess whether a genetic causal link exists between air pollution and APOs and the potential effects of this relation.

METHODS

A novel two-sample Mendelian randomisation (MR) study used pooled data from a large-scale complete genome correlation study. The primary analysis method was inverse variance weighting (IVW), which explored the expose-outcome relationship for assessing single nucleotide polymorphisms (SNPs) associated with air pollution. Further sensitivity analysis, including MR-PRESSO, MR-Egger regression, and leave-one analysis, was used to test the consistency of the results.

RESULTS

There was a significant correlation between air pollution-related SNPs and APOs. A robust causal link was found between genetic susceptibility to air pollution and APOs.

CONCLUSIONS

Our MR analysis reveals a genetic causal relation between air pollution and APOs, which may help provide new insights into further mechanisms and clinical studies in air pollution-mediated APOs.

LDL-C and TC mediate the risk of PNPLA3 inhibition on cardiovascular diseases

BACKGROUND

PNPLA3 is a promising target for the treatment of Metabolic Dysfunction-Associated Steatotic Liver Disease. ARO-PNPLA3 is a drug that efficiently lowers PNPLA3 expression in hepatocytes at the mRNA level, resulting in a significant reduction in liver fat in Phase I clinical trials. However, the long-term effects and potential side effects of ARO-PNPLA3 are not well understood.

METHODS

We conducted a two-sample, two-step Mendelian randomization (MR) analysis to investigate the association between PNPLA3 inhibition and 10 cardiovascular diseases (CVDs), as well as the role of lipid traits as mediators. We identified genetic variants near the PNPLA3 gene, which are linked to liver fat percentage, as instrumental variables for inhibiting PNPLA3. Additionally, positive control analyses on liver diseases were conducted to validate the selection of the genetic instruments.

RESULTS

Genetically predicted PNPLA3 inhibition significantly increased the risk of coronary atherosclerosis (1.14, 95% CI 1.06, 1.23), coronary heart disease (1.14, 95% CI 1.08, 1.21), and myocardial infarction (1.16, 95% CI 1.08, 1.26). Suggestive associations were observed for increased risk of heart failure (1.09, 95% CI 1.02, 1.17, P = 0.0143) and atrial fibrillation (1.17, 95% CI 1.00, 1.36, P = 0.0468). Blood low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) mediated approximately 16-25%, 16-30%, and 14-22% of the associations between PNPLA3 inhibition and coronary atherosclerosis, myocardial infarction, and coronary heart disease, respectively.

CONCLUSION

This study suggests that PNPLA3 inhibition increases the risk of major CVDs. Moreover, blood LDL-C and TC may mediate a significant proportion of the associations between PNPLA3 inhibition and coronary atherosclerosis, coronary heart disease, or myocardial infarction.

Causal effects of exposure to ambient air pollution on cancer risk: Insights from genetic evidence

Air pollution has been increasingly linked to cancer risk. However, the genetic causality between air pollution and cancer risk remains poorly understood. To elucidate the potential roles of air pollution (NOx, NO2, PM2.5, PM course, and PM10) in the risk of 18 specific-site cancers, large-scale genome-wide association studies with a novel Mendelian randomization (MR) method were employed. Our MR analyses revealed significant associations between certain air pollutants and specific types of cancer. Specifically, a positive association was observed between NOx exposure and squamous cell lung cancer (OR: 1.96, 95%CI: 1.07-3.59, p = 0.03) as well as esophageal cancer (OR: 1.002, 95%CI: 1.001-1.003, p = 0.005). Genetically predicted NO2 exposure was found to be a risk factor for endometrial cancer (OR 1.41, 95%CI: 1.03-1.94, p = 0.03) and ovarian cancer (OR: 1.49, 95%CI: 1.14-1.95, p = 0.0037). Additionally, genetically predicted PM2.5 exposure was associated with an increased risk of ER+ breast cancer (OR: 1.24, 95%CI: 1.03-1.5, p = 0.02) and ER- breast cancer (OR: 2.57, 95%CI: 1.05-6.3, p = 0.04). PM course exposure was identified as a risk factor for glioma (OR: 487.28, 95%CI: 13.08-18,153, p = 0.0008), while PM10 exposure exerted a detrimental effect on mesothelioma (OR: 114.75, 95%CI: 1.14-11,500.11, p = 0.04) and esophageal cancer (OR: 1.01, 95%CI: 1.007-1.02, p = 0.03). These findings underscored the importance of mitigating air pollution to reduce the burden of cancer and highlight the need for further investigations to elucidate the underlying mechanisms involved in these associations.

Associations between ADHD and risk of six psychiatric disorders: a Mendelian randomization study

BACKGROUND

Observational studies and diagnostic criteria have indicated that Attention Deficit Hyperactivity Disorder (ADHD) frequently comorbid with various psychiatric disorders. Therefore, we conducted a Mendelian randomization (MR) study to explore this potential genetic association between ADHD and six psychiatric disorders.

METHODS

Using a two-sample Mendelian randomization (MR) design, this study systematically screened genetic instrumental variables (IVs) based on the genome-wide association studies (GWAS) of ADHD and six psychiatric disorders, with the inverse variance weighted (IVW) method as the primary approach.

RESULTS

The study revealed a positive and causal association between ADHD and the risk of ASD, with an odds ratio (OR) of 2.328 (95%CI: 1.241-4.368) in the IVW MR analysis. Additionally, ADHD showed a positive causal effect on an increased risk of schizophrenia, with an OR of 1.867 (95%CI: 1.260-2.767) in the IVW MR analysis. However, no causal effect of Tic disorder, Mental retardation, Mood disorders and Anxiety disorder with ADHD was found in the analysis mentioned above.

CONCLUSION

Our MR analysis provides robust evidence of the causal role of ADHD in increasing the risk of ASD and schizophrenia. However, ADHD is not associated with the risk of Tic Disorder, Mental Retardation, Mood Disorders and Anxiety Disorder. This suggests the need for increased attention to the co-occurrence of ADHD-ASD or ADHD-schizophrenia and the implementation of timely intervention and treatment.

Case report: Targeted sequencing facilitates the diagnosis and management of rare multifocal pure ground-glass opacities with intrapulmonary metastasis

Introduction

Treatments for multiple ground-glass opacities (GGOs) for which the detection rate is increasing are still controversial. Next-generation sequencing (NGS) may provide additional key evidence for differential diagnosis or optimal therapeutic schedules.

Case presentation

We first reported a rare case in which more than 100 bilateral pulmonary GGOs (91.7% of the GGOs were pure GGOs) were diagnosed as both multiple primary lung cancer and intrapulmonary metastasis. We performed NGS with an 808-gene panel to assess both somatic and germline alterations in tissues and plasma. The patient (male) underwent three successive surgeries and received osimertinib adjuvant therapy due to signs of metastasis and multiple EGFR-mutated tumors. The patient had multiple pure GGOs, and eight tumors of four pathological subtypes were evaluated for the clonal relationship. Metastasis, including pure GGOs and atypical adenomatous hyperplasia, was found between two pairs of tumors. Circulating tumor DNA (ctDNA) monitoring of disease status may impact clinical decision-making.

Conclusions

Surgery combined with targeted therapies remains a reasonable alternative strategy for treating patients with multifocal GGOs, and NGS is valuable for facilitating diagnostic workup and adjuvant therapy with targeted drugs through tissue and disease monitoring via ctDNA.