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

Abstract 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 (ΔBW), body mass index (BMI) (ΔBMI) and bodyweight per year (ΔBW/y) to analysis their impact on NAFLD and MetS in multi-variable regression models, and explored the potential mediators that associated ΔBMI with NAFLD by mediation analysis. Results ΔBMI, ΔBW and ΔBW/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 ΔBMI (third trisection), ΔBW and ΔBW/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 ΔBMI with NAFLD. ΔBMI 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.