Exploration the effect of air pollution on the incidence of myasthenia gravis: An empirical study from Chengdu

Abstract

Myasthenia gravis (MG) is an autoimmune disease caused by antibodies attacking and destroying acetylcholine receptors (AChR) at the neuromuscular junction. Although the exact cause of the incidence of MG is unclear, it is believed to involve abnormal immune system function, certain genetic factors, and environmental influences. However, limited existing studies explore the correlation between the incidence of MG and the atmospheric environment. Therefore, this study aimed to investigate the correlation between the incidence of MG and potential air pollution factors in Chengdu. We used the admission data of MG patients from 2017 to 2023 in a large tertiary general hospital in Chengdu to analyze such correlation with meteorological conditions and air pollution. The data were processed using first-order difference to eliminate the effect of autocorrelation on the regression results. Then we selected the variables using stepwise regression, finding the independent variables who have significant effects on the incidence of MG. Based on this, a multiple linear regression model was established. To solve the problem of multicollinearity among the selected variables, we used ridge regression to amend the model. We also used median regression to reduce the impact of outliers in order to improve the stability of the model. Finally, we assessed variables' importance using random forest and explored causal relationship with causal forest. The results consistently showed a significant positive effect of carbon monoxide (CO) concentration on the incidence of MG, as well as several meteorological conditions and air pollution variables that influenced the incidence of MG to some extent.