Using Mendelian randomization to explore causal associations between five autoimmune diseases and nonalcoholic fatty liver disease

[Abstract] Objective To investigate the causal relationship between immune diseases such as inflammatory bowel disease(IBD), psoriasis (PsO), rheumatoid arthritis (RA), multiple sclerosis (Ms), and systemic lupus erythematosus (SLE) and nonalcoholic fatty liver disease(NAFLD) using dual sample bidirectional Mendelian randomization (MR), and to provide genetic evidence to support the association between immune diseases and the risk of NAFLD. Methods MR Egger regression, Weighted median, Random effects inverse variance weighting (IVW), Weighted model, and Simple model were used to conduct Mendelian randomization analysis on the causal relationship between 5 immune diseases and NAFLD. Results In the principal analysis, IVW estimation indicated that IBD and MS were risk factors for NAFLD. No evidence was found that PsO, RA, and SLE were directly related to the onset of NAFLD. Conclusion There is a causal relationship between IBD and MS in the development of NAFLD, which may increase the risk of NAFLD.