Role of the liver in alcohol-induced alteration of high-density lipoprotein metabolism.

The effect of alcohol intake on the serum levels of high-density lipoprotein cholesterol (HDL-ch), apoprotein A-I (apo A-I), and apoprotein A-II (apo A-II) was investigated in 15 habitual alcohol drinkers without liver injury (group A), 17 with mild hepatic damage (group B), and five with advanced liver disease (group C). The serum level of HDL-ch was higher in group A than in 10 nondrinkers (P less than 0.01) but lower in group B (P less than 0.05) and markedly lower in group C (P less than 0.01). The level of apo A-I was also higher in group A (P less than 0.05), although the level of apo A-II was not. To elucidate the effect of alcohol on apo A-I production by hepatocytes, the synthesis of apo A-I and albumin by cultured rat liver cells in the presence of ethanol was also investigated. Ethanol enhanced the production of apo A-I but not that of albumin. The results suggest that serum HDL is elevated in habitual alcohol drinkers without liver injury and that the elevation of HDL in blood is mainly dependent on the increase of apo A-I synthesis in the liver.