Increased serum resistin in nonalcoholic fatty liver disease is related to liver disease severity and not to insulin resistance

CONTEXT: The recently discovered hormone resistin is linked to the development of insulin resistance, but direct evidence of resistin levels in humans with nonalcoholic fatty liver disease (NAFLD) is lacking. METHODS: We conducted this study to assess the relationship between serum resistin and NAFLD. We measured serum resistin and biochemical, hormonal, and histological correlates in 28 NAFLD patients, 33 controls, and 30 obese patients [body mass index (BMI), >30 kg/m2] without NAFLD. RESULTS: Resistin and adiponectin expression were measured in sc adipose tissue by quantitative RT-PCR. Resistin was higher in NAFLD patients compared with controls (5.87 +/- 0.49 vs. 4.30 +/- 0.20 ng/ml; P = 0.002) and obese patients (4.37 +/- 0.27 ng/ml; P = 0.002). Increased resistin mRNA was also found in the adipose tissue of NAFLD patients compared with controls and obese subjects. CONCLUSIONS: Both NAFLD and obese patients had lower adiponectin levels, whereas leptin was increased only in the obese group. No correlation was found between resistin and high-sensitivity C-reactive protein, BMI, homeostasis model assessment, insulin, glucose, transaminases, and lipid values. A positive correlation was found between resistin and histological inflammatory score. These data report increased resistin in NAFLD patients that is related to the histological severity of the disease, but do not support a link between resistin and insulin resistance or BMI in these patients.