Background: The mechanisms of the positive relationship between alcohol intake and plasma concentration of high-density lipoprotein (HDL) are still unclear. The present study shows the metabolism modifications of apolipoprotein (apo) AI and apoAII in normolipidaemic healthy volunteers after a period of moderate red wine consumption.
Design: Five non-smoking male subjects were studied at the end of two consecutive 4-week periods, one without alcohol and the other with an intake of 50 g per day of alcohol, in random order. The metabolic parameters of apoAI and apoAII in HDL were determined after endogenous labelling using amino acid labelled with stable isotope. Cholesterol, triacylglycerols, HDL-cholesterol, apoAI, apoAII, LpAI, LpAI:AII were determined in plasma at the end of the two study periods.
Results: Cholesterol and triacylglycerols did not vary significantly during the two periods, whereas HDL-cholesterol increased from 43.8 to 50.0 mg dL-1 (P < 0.05). ApoAI and apoAII increased significantly (20% and 60% respectively) after the diet was supplemented with alcohol. LpAI:AII increased from 73.8 to 101.6 mg dL-1 (+32%) (P < 0.05), whereas alcohol had no effect on the concentration of LpAI. The alcohol treatment did not significantly alter the metabolism of apoAI. Conversely, the fractional catabolic rate of apoAII decreased significantly by 21% (P < 0.05) with alcohol, whereas the production rate of apoAII tended to increase by 18% (P = 0.08).
Conclusion: The decrease in the fractional catabolic rate of apoAII could lead to an accumulation of apoAII-containing lipoproteins in plasma and account for the dramatic increase in LpAI:AII observed in the plasma of subjects consuming alcohol.