Factors affecting the serum levels of adipokines in Korean male patients with nonalcoholic fatty liver disease.

BACKGROUND/AIMS: Adipokines are associated with various metabolic disorders including insulin resistance, obesity, and dyslipidemia. Metabolic disorders have also been reported to be associated with nonalcoholic fatty liver disease (NAFLD). The aim of this study was to determine the relationship between the serum adipokine levels and the degrees of hepatic fat infiltration in NAFLD. This study also attempted to determine the independent factors influencing the serum adipokine levels in NAFLD. METHODOLOGY: Sixty-five Korean male patients were enrolled in this study. The degree of hepatic fat infiltration was classified into the following three groups according to the ultrasonographic findings: Group I, normal liver; Group II, mild fatty liver; and Group III, moderate to severe fatty liver. The anthropometric parameters, fasting serum adipokine levels including leptin, adiponectin and resistin were measured in all subjects. The level of insulin resistance was estimated using the HOMA-IR. RESULTS: The serum leptin levels increased with increasing degree of hepatic fat infiltration (mean +/- SD: Group I, 2.052 +/- 1.071; Group II, 2.879 +/- 1.016; and Group III, 4.457 +/- 1.965 ng/mL, P < 0.001). However, the serum adiponectin and resistin levels were similar. The fasting serum insulin level was only a related factor for the changes in the serum leptin levels (P = 0.004). There were no related factors for the change in the serum adiponectin and resistin levels. CONCLUSIONS: This study suggests an indirect role for leptin in the pathogenesis of NAFLD by inducing insulin resistance, resulting in increased fasting serum insulin level.