Investigation of adropin and leptin levels in pediatric obesity-related nonalcoholic fatty liver disease.

Aim: Nonalcoholic fatty liver disease (NAFLD) is the accumulation of excess fat in the liver in the absence of alcohol consumption, which is commonly associated with obesity and increased risk of atherosclerosis as well as insulin resistance. Adropin is a recently identified protein encoded by the gene related with energy homeostasis, which is expressed in the liver and the brain and has a role in preventing insulin resistance and obesity. The aim of this study was to investigate the serum adropin and leptin levels in obese adolescents and compare the patients with, and without, NAFLD and with healthy controls.

Methods: Sixty-four obese adolescents (30 with NAFLD, 34 without NAFLD) and 36 healthy controls were enrolled in the study. Serum adropin and leptin levels were evaluated by sandwich enzyme-linked immunosorbent assay.

Results: Serum adropin levels were significantly lower in obese children than healthy controls (3.2±1.0 and 9.2±1.2 ng/mL, respectively, p=0.001). Serum leptin levels were significantly higher in patients than in controls (12.4±1.1 and 4.1±3.1 pg/mL, respectively; p=0.000). Serum adropin levels of patients with NAFLD were significantly lower than in patients without NAFLD (2.9±0.5 and 3.5±1.2 ng/mL, respectively; p=0.023) and healthy controls (p=0.000). Logistic regression analysis showed that a decrease in adropin levels was the only independent factor for fatty liver disease in obese adolescents (odds ratio: 3.07, 95% confidence interval 1.14-8.2, p=0.026). Leptin, relative weight and HOMA-IR of the patients were not independent risk factors for NAFLD.

Conclusions: In this study, serum adropin levels were significantly lower in obese adolescents with fatty liver disease compared to patients without fatty liver disease and healthy controls. Lower adropin level was an independent risk factor for NAFLD in obese adolescents in logistic regression analysis. Assessment of serum adropin concentrations may provide a reliable indicator of fatty liver disease in obese adolescents.