Bidirectional two-sample Mendelian randomization study of insomnia and myocardial infarction
Aim To explore the association between insomnia and myocardial infarction(MI)using bidirectional two-sample Mendelian randomization(MR).Methods The summary statistics of MI were obtained from genome-wide association studies(GWAS),and single nucleotide polymorphisms(SNP)associated with insomnia phenotype were select-ed as instrumental variables.Inverse variance weighting(IVW)was used to evaluate the causal relationship between in-somnia and MI.Results MR analysis showed that there was positive relationship between insomnia and MI(IVW:OR=1.015,95%CI 1.004~1.027,P=0.007).There was no horizontal pleiotropy and heterogeneity in instrumental variables.Sensitivity analysis suggested that MR analysis results were stable.Reverse MR analysis showed no causal re-lationship between MI and increased risk of insomnia(IVW:OR=0.725,95%CI 0.466~1.126,P=0.152),and the statistical results were stable after the removal of outliers.Conclusion Insomnia is a risk factor for MI and there was positive relationship between insomnia and MI.However,there was no causal relationship between MI and an increased risk of insomnia.