The impact of body weight gain on nonalcoholic fatty liver disease and metabolic syndrome during earlier and later adulthood

Aim: Body weight gain adds risk for metabolic disorders and there are different metabolic changes in earlier and later adulthood. However, its impact on non-alcoholic fatty liver disease (NAFLD) was indeterminate. The aim of current study was to evaluate the impact of body weight gain on NAFLD and metabolic syndrome (MetS) during overall, earlier (25-40 y) and later (over 40 y) adulthood. Methods: 1119 subjects were selected to calculate changes in body weight (Delta BW), body mass index (BMI) (Delta BMI) and bodyweight per year (Delta BW/y) to analysis their impact on NAFLD and MetS in multi-variable regression models, and explored the potential mediators that associated Delta BMI with NAFLD by mediation analysis. Results: Delta BMI, Delta BW and Delta BW/y in whole adulthood were all positively associated with NAFLD and MetS. Body weight gain during earlier adulthood was more strongly associated with NAFLD than those during later adulthood. In NAFLD, the ORs of Delta BMI (third trisection), Delta BW and Delta BW/y were 3.86 (2.25, 6.57), 1.05 (1.02, 1.09) and 2.05 (1.29, 3.24) during earlier adulthood, and 1.47 (1.09, 2.02), 1.02 (1.00, 1.06), and 1.04 (. 99, 1.13) over 40 y. Insulin and HOMA-IR were important intermediates that associated Delta BMI with NAFLD. Delta BMI in earlier adulthood increased higher insulin and insulin resistance (IR) than later adulthood. Conclusions: Body weight gain in adulthood was positively associated with NAFLD and MetS, and the association was stronger in earlier than later adulthood. Insulin and IR were important mediators that contributed to the association. (C) 2016 Elsevier Ireland Ltd. All rights reserved.