Objective To investigate the association between metabolic associated fatty liver disease（MAFLD） and sleep disorders. Methods A total of 222 patients with MALFD who were admitted to Panjin Central Hospital from February 2020 to February 2021 and 270 healthy individuals were enrolled as subjects. According to age, the patients with MALFD were divided into youth group with 93 patients, middle-aged group with 76 patients, and elderly group with 53 patients; according to controlled attenuation parameter（CAP） of liver fat, the patients were divided into non-steatosis group with 23 patients, mild steatosis group with 85 patients, moderate steatosis group with 76 patients, and severe steatosis group with 38 patients; according to liver stiffness measurement（LSM）, the patients were divided into non-progressive fibrosis group with 124 patients and progressive fibrosis group with 98 patients. Related data were collected, including general information such as age and sex and laboratory markers such as routine blood test results and biochemistry, and after informed consent was obtained, three sleep scales, i.e., Pittsburgh Sleep Quality Index（PSQI） scale, Epworth Sleepiness Scale（ESS）, and Morningness-Eveningness Questionnaire（MEQ）, were completed independently. The MAFLD group and the healthy control group were compared in terms of general information and laboratory markers to investigate the association between MAFLD and sleep disorders under different grouping criteria. The chi-square test was used for comparison of categorical data between two groups; the t-test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U rank sum test was used for comparison of non-normally distributed continuous data between two groups; the Kruskal-Wallis H test was used for comparison between the groups of MAFLD patients with different ages and degrees of hepatic steatosis and pairwise comparison within each group. A logistic regression analysis was used to investigate the independent risk factors for MAFLD, and a Spearman correlation analysis was used to investigate the correlation of hepatic steatosis degree and fibrosis degree with sleep quality, somnolence, and circadian rhythm. Results There were significant differences in age, sex, hypertension, diabetes, and smoking between the MAFLD group and the healthy control group（all P<0.05）. Compared with the healthy control group, the MAFLD group had significantly higher hemoglobin, white blood cell count, lymphocyte percentage, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, serum uric acid, low-density lipoprotein, total bilirubin, total cholesterol, triglyceride, and body mass index and significantly lower albumin and high-density lipoprotein（all P<0.05）. Compared with the healthy control group, the MAFLD group had significantly higher PSQI score（t=35.529, P<0.001） and ESS score（t=24.647, P<0.001） and significantly lower MEQ score（t=-22.416, P<0.001） and sleep time（t=-8.660, P<0.001）. With the increase in age in the MAFLD group, hepatic steatosis degree, liver fibrosis degree, and PSQI score showed an increasing trend, and pairwise comparison of each scoring factor between groups showed statistical significance（all P<0.05）. Compared with the healthy control group, the MAFLD group had a significantly higher proportion of patients with definitely evening type, moderately evening type, or intermediate type and a significantly lower proportion of patients with moderately morning type or definitely morning type（all P<0.05）, and MEQ score tended to decrease with the increase in hepatic steatosis degree and liver fibrosis degree, with significant differences between two groups（all P<0.05）. The multivariate logistic regression analysis showed that overweight/obesity（odds ratio [OR]=3.166, P=0.027）, diabetes（OR=6.811, P=0.045）, increase in white blood cell count（OR=2.301, P<0.001）, increase in lymphocyte percentage（OR=1.316, P=0.002）, poor sleep quality（OR=8.493, P<0.001）, a high degree of somnolence（OR=5.420, P<0.001）, and circadian rhythm disturbance（OR=3.805, P<0.001） were risk factors for MAFLD. The Spearman correlation analysis showed that in the MAFLD group, hepatic steatosis degree was positively correlated with PSQI score（r=0.444, P<0.001） and ESS score（r=0.339, P<0.001） and was negatively correlated with MEQ score（r=-0.195, P=0.004）, and liver fibrosis degree was positively correlated with PSQI score（r=0.518, P<0.001） and ESS score（r=0.373, P<0.001） and was negatively correlated with MEQ score（r=-0.250, P=0.004）. Conclusion Compared with healthy individuals, the patients with MAFLD often have sleep disorders, and the severity of sleep disorders increases with age, hepatic steatosis degree, and liver fibrosis degree. Obesity, diabetes, and sleep disorders are risk factors for the onset of MAFLD. [ABSTRACT FROM AUTHOR]