Assessment of the Relationship Between Prevalence of Reporting Fatty Liver Disease by Ultrasound and Body Mass Index in Children

Background: Obesity is the major cause of nonalcoholic fatty liver disease (NAFLD) as the most common form of chronic liver disease. Prevention of obesity can be useful in reducing the incidence of NAFLD.
Objectives: This study evaluated the prevalence of fatty liver in relation with body mass index (BMI) by means of ultrasound in high school students of Zanjan.
Methods: In this cross-sectional study, three hundred high school students aged 12 to 18 years, from Zanjan city were selected randomly and divided to three groups with one hundred children in each group, based on body mass index. Only 240 of them participated in the study. The participants were examined by a pediatrician. Weight, height and waist circumferences were measured at baseline. Liver ultrasound was performed for all children and grade of fatty liver was determined.
Results: There was a significant correlation between grade of fatty liver with BMI, gender and age (P = 0.000, P = 0.000 and P = 0.006, respectively). Boys had higher rates of fatty liver than girls. Our study showed a strong association between BMI and prevalence of fatty liver on ultrasound. However, there was no relation between severity of fatty liver and waist circumference (P = 0.067). The waist circumference was greater in boys, and it increased with age. The mean BMI in children with grade 1 and 2 fatty liver was 26.79 and 30.5, respectively.
Conclusions: According to the study hypothesis, based on BMI, the degree of NAFLD in children was predictable. Ultrasound of liver is one of the assessment methods of fatty liver but it is not a diagnostic method; it is useful for prevention in order to reduce BMI.

Keywords
Body Mass Index; Nonalcoholic Fatty Liver Disease; Children; Ultrasound