Prognostic factors in resolution of nonalcoholic fatty liver disease post bariatric surgery in adolescents

Abstract

BackgroundThe long-term effect of bariatric surgery on adolescent non-alcoholic fatty liver disease is not clear. ObjectivesTo evaluate longitudinal change in serum alanine aminotransferase (ALT) levels and to determine the factors independently associated with this change over 2 years after bariatric surgery in adolescents with severe obesity. SettingAn observational prospective cohort from the Teen-LABS Consortium. MethodsWe examined the relationship of longitudinal change in serum ALT (% change and normalization) to change in body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), high- (HDL) and low-density lipoprotein cholesterol, A1C and fasting glucose, accounting for age, sex, race-ethnicity, blood pressure, and baseline BMI in 219 adolescents during the first 2 years post-surgery. ResultsMean BMI declined from a baseline of 52.6 to 37.2 kg/m2 at 2 years (P < .01). Alanine aminotransferase decreased significantly from baseline (36.5 [95% CI: 31.4, 41.7]) to 6 months (30.5 [95% CI: 25.4, 35.6]), and remained stable at 12 and 24 months, all P < .01 versus baseline. After adjustment, improvement in BMI, fasting glucose, HOMA-IR, triglycerides, TG/HDL ratio, and HDL were independently associated with reduced ALT at 6 months. These remained significantly associated with a decline in ALT after adjusting for BMI change. The %participants with elevated ALT decreased from 71% at baseline to 42% and 36% at 1 and 2 years post-surgery. ConclusionsBariatric surgery resulted in significant and sustained improvement in ALT levels over 2 years. Although associated with weight loss, this decline was also associated with improved metabolic indices, independent of weight loss.