Introduction
NAFLD, Sleep, liver injuries, MR, cirrhosis and hepatocellular carcinoma
CHRONIC LIVER DISEASE, LIVER FIBROSIS, HEPATIC STEATOSIS, NONALCOHOLIC FATTY LIVER DISEASE, DISEASES, STEATOHEPATITIS
Nonalcoholic fatty liver disease (NAFLD), one of the most common chronic liver disease in the world, affects 25% of the population worldwide and its prevalence is expected to increase further in the near future. NAFLD and its associated consequences have become one of the major public health problems due to changes in lifestyle and dietary structure. NAFLD can be accompanied by many subsequent extensive liver injuries, ranging from simple hepatic steatosis to steatohepatitis, advanced liver fibrosis, cirrhosis and hepatocellular carcinoma (Sleep is crucial for general health, and the amount of good sleep is beneficial to health (With the rapid development of genome-wide association studies (GWAS), Mendelian randomization (MR) analysis with phenotype-associated single nucleotide polymorphism(SNP) s as instrumental variables (IVs) is increasingly used in clinical settings to explore the causal relationships between various factors and diseases. Information about genetic variation is used to identify potential effects and to reveal causal relationships between the two. Although randomized controlled trial (RCT) have a high level of evidence, they are often difficult to implement due to their high cost, time consuming nature and sometimes ethical issues involved. In this case, MR provides a useful method, especially when observational studies yield associations with a tendency to bias due to confounding or reverse causality. As an extension of the MR approach, two-sample MR allows aggregated data from GWAS to be used in MR studies, rather than just individual-level data, and without regard to cost. Overall, under the specific assumptions of IVs, a sound MR design can provide more reliable evidence than observational studies (Based on publicly available GWAS data from a large population, we used a two-sample bidirectional MR analysis to illustrate the effect of sleep on the development of NAFLD, thus further clarifying the causal relationship between sleep and the development of NAFLD. In order to understand the risk factors for NAFLD and provide new insights for the prevention of NAFLD.