ABSTRACT
Background Existing research has focused on new-onset asthma and viral infections, particularly respiratory syncytial virus (RSV). However, studies on whether COVID-19 can induce asthma are limited.Methods We performed bidirectional two-sample Mendelian Randomization (MR) to assess the potential causal relationship between COVID-19 and asthma using genome-wide association study (GWAS) summary data obtained from the COVID-19 Host Genetic Initiative GWAS Meta-analysis Round 5 (release date: 18 January 2021). Several methods (random-effects inverse variance weighted, weighted median, MR-Egger regression, and MR-PRESSO) were used to ensure the robustness of the causal effects. Heterogeneity was measured using Cochran's Q value. Horizontal pleiotropy was evaluated using MR-Egger regression and leave-one-out analyses.Results We observed a significant causal association between COVID-19 hospitalisation and asthma (odds ratio (OR) = 1.042, 95% Confidence Interval (CI) = 1.004–1.081, p = 0.031), indicating a significantly increased risk of COVID-19 hospitalisation associated with asthma. However, no statistically significant causal relationships were observed for COVID-19 susceptibility (OR = 1.023, 95% CI = 0.931–1.124, p = 0.637), COVID-19 severity (OR = 1.006, 95% CI = 0.978–1.035, p = 0.669), and asthma.Conclusions COVID-19 can trigger the onset of asthma. Individuals experiencing prolonged coughing, chest tightness, or difficulty in breathing long after recovery from COVID-19 should remain vigilant about the possibility of developing asthma.