Causal Relationships Between Emotional Instability and Respiratory Diseases: A Mendelian Randomization Analysis

Background: In the past few years, there has been a growing fascination with the connection between mental well-being and respiratory conditions. However, the causal relationship between personality traits and respiratory diseases remains largely unknown. This study aimed to investigate the link between genetically predicted emotional instability and eight respiratory conditions using a two-sample Mendelian randomization (MR) analysis.
Methods: In a GWAS dataset from the UK Biobank, SNPs linked to emotional instability were discovered among 204,412 participants of European descent. Genetic information for lung cancer, pulmonary fibrosis, pneumonia, and bronchiectasis was obtained from the European Bioinformatics Institute (EBI). While data for chronic obstructive pulmonary disease (COPD), pulmonary embolism, chronic cough, and asthma was collected from the UK BioBank. An MR study was carried out to investigate how specific single nucleotide polymorphisms (SNPs) impact the likelihood of developing the eight respiratory conditions listed. Our main approach for the initial screening was the utilization of inverse variance weighting (IVW). Multiplicity was assessed using the MR-Egger regression test, while heterogeneity was evaluated with Cochran’s Q test. To ensure the reliability of the findings, a leave-one-out analysis was conducted.
Results: IVW found evidence that emotional instability had a significant causal effect on the increased risk of COPD (OR = 1.009; 95% CI = 1.001– 1.017; P = 0.022), pneumonia (OR = 1.648; 95% CI = 1.036– 2.622; P = 0.035), chronic cough (OR = 1.077; 95% CI = 1.013– 1.145; P = 0.017) and increased risk of asthma (OR = 1.073; 95% CI = 1.026– 1.123; P = 0.002) had a significant causal relationship. This association remained strong in the case of potential confounders, including smoking. Additionally, the instrumental variable weighted method in this study did not find any indication of a causal link between emotional instability and lung cancer, pulmonary embolism, pulmonary fibrosis, and bronchiectasis (all P > 0.05).
Conclusion: The research discovered a link between emotional instability and a higher likelihood of developing COPD, pneumonia, chronic cough, and asthma. This study also found that emotional instability was not causally associated with lung cancer, pulmonary embolism, pulmonary fibrosis, and bronchiectasis.