Predictors for Incidence and Remission of Nonalcoholic Fatty Liver Disease in Obese Children and Adolescents

Background/purpose: The status of nonalcoholic fatty liver disease (NAFLD) can wax and wane over time in children. However, the factors affecting its incidence and remission remain elusive. We aimed to investigate NAFLD incidence, remission and predicting factors in obese children.

Methods: Obese children aged 9-10 and 12-13 years were recruited from schools and followed up for 2 years. Liver ultrasonography was performed at baseline and Year 1. Alanine aminotransferase (ALT) concentrations were measured at baseline, Year 1 and Year 2. Elevated ALT was defined as above 26 U/L for boys and 22 U/L for girls. Four NAFLD susceptible genes, including PNPLA3, GCKR, TM6SF2 and MBOAT7, were genotyped. We analyzed the effects of these risk factors on the incidence and remission of NAFLD and elevated ALT.

Results: At baseline, 86 of 440 (19.5%) subjects had ultrasonography-diagnosed NAFLD. At Year 1, of 264 subjects without NAFLD at baseline, 20 (7.6%) developed NAFLD. The baseline BMI z-score and increment in BMI z-score independently predicted incident NAFLD. Of the 68 subjects with NAFLD at baseline, 36 (52.9%) had NAFLD remission. Decrement in BMI z-score independently predicted NAFLD remission. The four studied NAFLD susceptible genes were not significantly associated with either the incidence or remission of NAFLD. In addition, changes in BMI z-score predicted the incidence and remission of elevated ALT from Year 1 to Year 2.

Conclusion: Obese children with increasing BMI are more likely to develop NAFLD and those with decreasing BMI are more likely to have NAFLD remission.