Background: Adiponectin is a circulating protein with hepatoprotective effects.
Aims: To study the relationship of excessive alcohol consumption and serum adiponectin levels (SAL).
Patients and Methods: The SAL were determined in (i) heavy drinkers without advanced liver damage during the course of alcohol withdrawal, (ii) patients with chronic hepatitis C virus (HCV) infection, (iii) patients with alcohol-associated cirrhosis, and (iv) healthy volunteers that consumed excessive amounts of alcohol for only a short period of time. Further, primary human hepatocytes (PHH) and adipocytes were incubated in vitro with alcohol or serum of patients.
Results: Patients with chronic alcohol consumption had significantly higher SAL than HCV-patients with comparable degrees of liver damage. In alcoholics, but not in HCV patients, SAL positively correlated with serum levels of aminotransferases. Further, SAL correlated with the amount of alcohol consumption but declined during the course of alcohol abstinence. After short-term excessive alcohol consumption SAL were not elevated in healthy individuals. Adiponectin mRNA was detectable in adipocytes but not in hepatocytes, and alcohol failed to induce adiponectin in both cell types. In contrast, serum of active drinkers induced adiponectin expression in adipocytes while serum from the same individuals collected after alcohol withdrawal had no effect.
Conclusions: Alcohol exhibits a specific effect on SAL that is dose and time dependent, and correlates with the degree of hepatic damage. Alcohol does not seem to affect adiponectin expression directly in adipocytes but potentially via mediators systemically released as a result of the chronic alcohol intake.