Adipokines and cytokines in non-alcoholic fatty liver disease


Dr Z. M. Younossi, Center for Liver Diseases at Inova Fairfax Hospital, 3289 Woodburn Road, Suite 375, Annanadale, Virginia 22003-6800, USA.


Background  Several adipocytokines have been implicated in the pathogenesis non-alcoholic fatty liver disease (NAFLD).

Aim  To assess adipocytokines in NAFLD patients and controls.

Methods  A total of 95 patients (26 non-alcoholic steatohepatitis (NASH), 19 simple steatosis (SS), 38 obese controls and 12 non-obese controls) were included. Fasting serum insulin, glucose, visfatin, resistin, adiponectin, tumour necrosis factor-α (TNF-α), interleukin-8 (IL-8) and IL-6 were determined. Univariate and multivariate analyses were used to compare groups and determine associations.

Results  Serum TNF-α and IL-8 were higher in NAFLD patients when compared with both obese and non-obese controls. Analysis involving all patients revealed a significant correlation between serum TNF-α and IL-8 (P < 6.319e−08), and between IL-6 and IL-8 (P < 5.271e−15). Homeostatic model assessment scores negatively correlated with adiponectin in NAFLD (P < 0.0032). Serum visfatin was higher in all three obese groups than in non-obese controls (P < 0.02, P < 0.002 and P < 0.008). Visfatin in NASH patients was lower than SS and obese controls. Although TNF-α was associated with NAFLD (P < 0.02), it was interdependent on visfatin. In comparison to SS, four factors were independently associated with NASH: age, alanine aminotransferase, IL-8 and adiponectin (P < 0.05). Multivariate analysis indicated that TNF-α was the only independent predictor of fibrosis in NASH (P < 0.0004).

Conclusion  These findings support a complex interaction between adipocytokines and the pathogenesis of NAFLD.