Exploring the causal relationship between atrial fibrillation/atrial flutter and insomnia based on Mendelian randomization

Objective To explore the potential bidirectional causality between atrial fibrillation (AF)/atrial flutter (AFL) and insomnia by two sample Mendelian randomization (MR).Methods The summary data for AF/AFL and insomnia were obtained from the genome-wide association study (GWAS) in IEU OpenGWAS project databases respectively. Significant and independent single nucleotide polymorphisms (SNPs) were extracted for MR analysis. Inverse-variance weighted (IVW), weighted median (WM), MR-Egger, simple mode and weighted mode were used to assess causality. In addition, the heterogeneity of IVW was examined by Cochran's Q test, MR-Egger test was used to detect horizontal pleiotropy, the outliers were detected by MR-PRESSO method to test gene pleiotropy and the leave-one-out sensitivity analysis was conducted to ensure result robustness.Results With AF/AFL as exposure and insomnia as outcome, a total of 47 SNPs were screened as instrumental variables, and IVW showed a positive causal relationship between AF/AFL and insomnia[OR=1.103, 95%CI(1.008, 1.208), P