Assessment of Abdominal Fat Distribution in Non-Alcoholic Fatty Liver Disease by Magnetic Resonance Imaging: a Population-based Study

Background: To investigate the association between non-alcoholic fatty liver disease (NAFLD) and quantitative measures of central adiposity in the general population using a semi-automated method on magnetic resonance imaging (MRI) data. Methods: Subjects were recruited from Golestan Cohort Study. Two groups of 120 individuals with and without fatty liver were randomly selected based on findings of ultrasound. Non-invasive diagnosis of NAFLD was made by combination of ultrasound and MRI. Various anthropometric indices including body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (VVHtR) were measured. Segmentation and calculation of visceral (VFA) and subcutaneous fat area (SFA) were performed on three levels of MRI slices using semi automated software. Results: A total of 109 individuals fulfilled the NAFLD criteria, while 92 subjects were selected as the control group. All obesity measures, except for SFA, were significantly higher in subjects with NAFLD compared to controls. Significant associations were found between NAFLD and adiposity indices, except for SFA, with the highest odds ratio observed in WFIR (OR: 3.37, CI: 1.40-3.70, P < 0.001). VFA also had the greatest correlation with ultrasound (r = 0.523, P < 0.001) and MRI (r = 0.546, P < 0.001) indicators of NAFLD. Conclusions: Quantitative measures of visceral adiposity are associated with NAFLD, while subcutaneous fat measures are poor indicators for identifying NAFLD. Compared to conventional anthropometric indices, VFA best correlates with ultrasound and MRI criteria of fatty liver.