Non-alcoholic fatty liver disease (NAFLD) is one of the most common diseases worldwide. Studies have shown that melatonin, as a regulatory hormone, is effective in different cell protective pathways. The aim of this study is to compare serum melatonin level of NAFLD patients with different stages of fibrosis and a healthy control group.

In this cross-sectional study patients aged more than 20 years old with elevated serum liver enzymes and trance abdominal sonographic diagnosis of fatty liver who met the exclusion criteria for NAFLD were included. The participants were categorized into the three following groups" 1) Severe fibrosis suspected of having Steatohepatitis with steatosis >285 dbm and fibrosis> 9.1kp. 2) Mild to moderate fibrosis (fibrosis: 6-9.0 KP and steatosis 240-285) and 3) control group with fibrosis< 6 KP and steatosis< 240 dbm according to fibroscan evaluation. Five ml of fasting vein blood was taken from each patient and control subject for laboratory assessment and a questionnaire including demographic , anthropometric, laboratories (serum ALT, AST, triglyceride, total cholesterol and melatonin level) and clinical data was completed for each on of them.

A total 97 persons included. The mean age was 42.21± 11 years old. 59 patients (60.0%) were female. According to fibrosis in three groups we observed that the melatonin levels were increased significantly .Indeed, based on CAP results the melatonin levels has significantly difference between healthy group and patients with severe steatosis. There was a direct association between increasing melatonin levels with liver enzymes.

Melatonin as a regulatory hormone may associate directly with liver cell injuries. Hence, considered regulatory substances such as melatonin either diagnostic or therapeutic can improve the patients' outcome.