摘要Background:Energy metabolism disorders contribute to the development of sepsis.Carnitine is essential for fatty acid metabolism and energy production.Therefore,we aimed to explore whether there is a causal relationship between carnitine levels and sepsis.Methods:Two-sample Mendelian randomization(MR)analysis was performed.The single nucleotide polymorphisms(SNPs)of carnitine from the genome-wide association(GWAS)study were used as exposure instrumental variables,and the susceptibility and severity of sepsis in the UK Biobank were used as outcomes.The inverse-variance weighted(IVW),MR-Egger,and weighted median methods were used to evaluate the causal relationship between exposure and outcomes.Heterogeneity was assessed using IVW and MR-Egger's and Cochran's Q tests,and pleiotropy was tested using the MR-Egger intercept and MR-PRESSO.Results:Using the IVW method,a one-standard-deviation increase in genetically determined carnitine levels was found to be associated with increased susceptibility to sepsis in populations under 75 years of age(odds ratio[OR]:2.696;95％confidence interval[Cl]:1.127-6.452;P=0.026)and increased severity of sepsis(OR:22.31;95％Cl:1.769-281.282;P=0.016).Sensitivity analysis did not re-veal heterogeneity or horizontal pleiotropy;therefore,the results indicated robustness.Conclusion:Genetic susceptibility to increased camitine levels in the blood may increase the susceptibility and severity of sepsis.There-fore,interventions at an early stage in patients with high carnitine levels may reduce the risk of developing sepsis.