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 similar to 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.