Decreased plasma adiponectin concentrations are closely associated with nonalcoholic hepatic steatosis in obese individuals

OBJECTIVES To evaluate whether subjects with nonalcoholic hepatic steatosis (HS) differed in their circulating adiponectin levels compared with those in subjects without HS and, if so, to examine to what extent such differences are mediated by the adverse pattern of the metabolic syndrome variables, typically observed in these subjects. DESIGN AND PATIENTS In a cross-sectional study, we analysed 68 healthy, mildly obese individuals with a negative or negligible daily alcohol consumption. MEASUREMENTS HS (by ultrasonography), glucose tolerance status (by oral glucose load), insulin resistance [by homeostasis model assessment (HOMA)], and plasma adiponectin concentration [by enzyme-linked immunosorbent assay (ELISA)] were measured. RESULTS Subjects with nonalcoholic HS (n = 43) had markedly lower plasma adiponectin concentrations than those without HS (n = 25) (5.6 +/- 3 vs. 10.8 +/- 4 mug/ml; P < 0.001). In addition, the former had significantly higher values for body mass index (BMI), waist/hip ratio (WHR), HOMA-insulin resistance score,plasma insulin (at fasting and after glucose load), plasma triglyceride and liver enzyme concentrations [such as alanine aminotransferase (ALT) and gamma-glutamyltranspeptidase (GGT)], and tended to have lower high density lipoprotein (HDL) cholesterol concentration. The significant differences in plasma adiponectin levels that were observed between the groups were little affected by adjustment for potential confounding variables, such as age, sex, BMI, WHR, lipids and HOMA-insulin resistance score. Similarly, in multivariate regression analyses, hypoadiponectinaemia significantly predicted the presence of HS (P < 0.001) and the increased levels of GGT and ALT (P < 0.05), independently of potential confounders. CONCLUSIONS These results show that decreased plasma adiponectin concentrations are closely correlated with nonalcoholic HS in healthy obese individuals.