Longitudinal analysis of risk of non-alcoholic fatty liver disease in adulthood.

Background & Aims: We aimed to determine how childhood body mass index and metabolic health, along with the change in body mass index between childhood and adulthood, determine the risk of adult non-alcoholic fatty liver disease.

Methods: Data from 2020 participants aged 3-18 years at baseline, followed up 31 years later, were examined to assess the utility of four childhood metabolic phenotypes (Metabolic Groups I: normal body mass index, no metabolic disturbances; II: normal body mass index, one or more metabolic disturbances; III: overweight/obese, no metabolic disturbances; IV: overweight/obese, one or more metabolic disturbances) and four life-course adiposity phenotypes (Adiposity Group 1: normal child and adult body mass index; 2, high child, normal adult body mass index; 3, normal child body mass index, high adult body mass index; 4, high child and adult body mass index) in predicting adult non-alcoholic fatty liver disease.

Results: The risk for adult non-alcoholic fatty liver disease was similar across all four groups after adjustment for age, sex, lifestyle factors and adult body mass index. Risk of adult non-alcoholic fatty liver disease was not increased among individuals overweight/obese in childhood but non-obese in adulthood. In contrast, overweight or obese adults, irrespective of their youth body mass index status, had ~eight-fold to 10-fold increased risk (P < 0.001).

Conclusions: Childhood overweight/obesity, not metabolic health, is associated with increased risk for adult non-alcoholic fatty liver disease. However, the increased risk associated with childhood overweight/obesity can be largely removed by obtaining a normal body mass index by adulthood.