Non-Alcoholic Fatty Liver Disease (NAFLD) is a common disorder leading to severe medical 45 conditions such as liver failure. Given the potential relation between sleep disturbance and NAFLD, we aimed 67 to investigate the association between deterioration of sleep and liver stiffness with NAFLD.

In this cross-sectional study, 134 Iranian adults who proven to have NAFLD were included. Liver 10 11 stiffness determined by Transient Elastography and sleep patterns were evaluated using Pittsburg sleep quality index.

Results showed that, sleep disorder was more prevalent in females (p = 0.007) and also, they had higher 17 18 liver stiffness than men (p= 0.001). Habitual sleep disorder which is the proportion of time spent in bed to the effective sleep time was worsen in patients with more severe liver stiffness (p = 0.037). In Categorized liver stiffness groups, there were significant association with overall sleep quality and liver stiffness (p = 0.001), but there was no significant association between sleep latency, sleep duration, daytime dysfunction and using sleeping pills with liver stiffness.

The present study indicates that in patients with NAFLD, bad sleep habits and poor sleep quality correlate with increased liver stiffness; suggesting that patient’s life style modification can improve the quality of their life and also prevent more severe disorders caused by sleep dysfunction.