Causal relationship between obstructive sleep apnea and asthma: a Mendelian randomization study

Abstract

Abstract Backgrounds: To date, the question of whether there is a causal relationship between obstructive sleep apnea and asthma remains unclear. Therefore, the aim of this study was to investigate the bidirectional causal relationship between obstructive sleep apnea and asthma (allergic and nonallergic). Methods We used publicly available genome-wide association study (GWAS) data for two-sample Mendelian randomization (MR) analysis. Inverse variance weighting (IVW) was used as the primary analysis method. MR‒Egger, weighted median and weighted mode were used as complementary methods to IVW. In addition, sensitivity analyses were performed using MR‒Egger, Cochran's Q test and leave-one-out analysis to ensure the robustness of the results. Results The IVW results showed that obstructive sleep apnea had a causal effect on both allergic asthma (OR = 1.16, 95% CI:1.01–1.34, P < 0.05) and nonallergic asthma (OR = 1.27, 95% CI:1.08–1.49, P < 0.05). In addition, allergic asthma was also causally associated with obstructive sleep apnea (OR = 1.10, 95% CI:1.04–1.17, P < 0.05). However, nonallergic asthma had no causal effect on obstructive sleep apnea (OR = 1.04, 95% CI:0.98–1.09, P = 0.190). Cochran's Q test, MR‒Egger regression and MR-PRESSO Global test suggested that the results were robust. Conclusions This study found that obstructive sleep apnea had a causal effect on both allergic and nonallergic asthma. Conversely, there was a causal effect of allergic asthma on obstructive sleep apnea. However, nonallergic asthma had no causal effect on obstructive sleep apnea.