Background: Animal studies have suggested that adiponectin may play a role in the pathogenesis of alcoholic and nonalcoholic fatty liver disease. Studies are limited that evaluated the role of adiponectin in the pathogenesis of nonalcoholic steatohepatitis (NASH).
Methods: To further our understanding of the role of adiponectin in the pathogenesis of NASH, the following studies were conducted. Serum adiponectin was measured and correlated with anthropometric and nutritional variables in 21 patients with biopsy-proven NASH and 19 age-, gender-, body mass index-, and body fat-matched controls. The effect of a mixed meal on serum adiponectin levels in a subgroup of patients (n = 24) with NASH and controls was assessed. In a separate cohort, liver samples belonging to healthy (n = 11), steatotic (n = 12), and NASH (n = 12) patients were used to further explore the role of adiponectin by measuring the expression of adiponectin and adiponectin receptor (AdipoR2) mRNA.
Results: Patients with NASH had significantly lower levels of serum adiponectin than controls (4.9 +/- 2.7 vs. 7.3 +/- 3.5 microg/mL, P = 0.02). While no significant correlation existed between serum adiponectin and anthropometric or nutritional variables, it was independently associated with age, high density lipoprotein, and triglycerides. Mixed meal had no effect on serum adiponectin either in patients with NASH or in controls. There was no expression of adiponectin mRNA in any of liver samples studied. However, AdipoR2 mRNA expression was higher in NASH than in steatotic and normal liver tissue.
Conclusion: These data show that adiponectin may have a role in the pathogenesis of human NASH and should be investigated further.