Serum adipokine levels in overweight patients and their relationship with non-alcoholic fatty liver disease

Aim. Non-alcoholic fatty liver disease (NAFLD) is a relevant public health matter in Western countries. The pathogenetic link between visceral fat, insulin resistance (IR) and NAFLD has been reported in literature. However, there are contradictions on the changes of adipokine levels in serum related to the presence of NAFLD. The aim of the present study was to evaluate the serum concentrations of a selected set of adipokines, that is, adiponectin, leptin, resistin and the pro-inflammatory cytokine interleukin-6 (IL-6) in overweight patients, and to clarify their relationship with NAFLD. Methods. Fasting serum levels of adipokines were determined in 42 consecutive overweight patients and in 25 lean controls. The degree of ultrasound (US) liver steatosis was graded according to the Hamaguchi score. Results. Liver steatosis was detected in 33 patients (78%) by US examination. Twelve patients with elevated transaminases levels showed significantly higher values of IR, leptin and resistin levels (P<0.05). Patients with steatosis presented a significantly higher leptin and a lower adiponectin levels (P<0.05) than controls. A significant inverse correlation was found between US steatosis progression and adiponectin and resistin levels (p<0.05). Considering the multiple logistic regression, adiponectin and leptin were good predictors to detect the presence of steatosis (p<0.05). Conclusion. Our data support the concept that adipokine level changes are closely linked with IR. In addition, serum adiponectin and leptin levels may be used as diagnostic markers to determine the presence of NAFLD in overweight patients.