Causal relationship between chronic obstructive pulmonary disease and respiratory tuberculosis susceptibility: A two-sample Bayesian weighted Mendelian randomization study

Abstract Background The causal relationship between COPD and respiratory TB is still unclear due to limited evidence from prospective studies. Therefore, the present study aimed to assess the causal relationship between COPD and respiratory TB using this two-sample Bayesian weighted Mendelian randomization (BWMR) study. Methods The genetic instrumental variants (IVs) for COPD and respiratory TB were obtained from the IEU Open GWAS project in 2021. The inverse variance weighted (IWV) method was used as the main statistical analysis method and was supplemented with weighted median and BWMR methods. Pleiotropy was tested using the MR-PRESSO global test and MR-Egger regression. Heterogeneity was analyzed using Cochran's Q statistics. The robustness of the results was tested using the leave-one-out sensitivity analysis method. Results In our two-sample BWMR analysis, we found that patients with COPD had a higher risk of respiratory TB based on IVW (OR = 1.259, 95% CI for OR: 1.011–1.568; p = 0.040), weighted median (OR = 1.287, 95% CI for OR: 0.981–1.688; p = 0 .069) and BWMR (OR = 1.240, 95% CI for OR: 1.013–1.518; p = 0.037). Reverse BWMR analysis showed that respiratory TB has no causal effect on COPD. We found no significant pleiotropy or heterogeneity in all selected IVs. The results were stable when removing the SNPs one by one. Conclusion This two-sample BWMR study provided compelling evidence that individuals with COPD are at a higher risk of respiratory TB at the genetic level, while respiratory TB has no causal effect on COPD.