[Biochemical bases of disturbed interactions between carbohydrate and fat metabolism in diabetes mellitus]

[Human ethanol-induced hyperlipoproteinemia (author's transl)]

Reversible hyperlipoproteinemia may be observed after ethanol loads in healthy man before any ethanol-induced disease is being established. Different pathogenetic ways to this acute ethanol-induced hyperlipoproteinemia have been investigated or postulated in recent years. Two main sites have appeared: changes in the metabolism of lipids and their precursors which depend from acutal oxidation of ethanol in the liver, and ethanol-induced activation of lipolysis in adipose tissue, transmitted by the sympathico-adrenal system. The changes in liver metabolism during ethanol oxidation have been well confirmed in many experiments, they nevertheless do not seem to lead to hyperlipoproteinemia in many experimental designs in animals and after drinkable amounts of ethanol in healthy man when lipolysis of adipose tissue is blocked and no food is ingested. After the intake of a fatty meal these triglycerides are becoming importance as a source of fatty acids. A possible increased de novo synthesis of palmitic acid may to a minor degree contribute to hypertriglyceridemia.

[Changes of triglycerid-fatty acids in healthy volunteers during acute ethanol ingestion with and without blocking peripheral lipolysis (author's transl)]

This investigation decided to answer the question of the origin of fatty acids for the increased synthesis of triglycerides in acute ethanol-induced hyperlipoproteinemia. Healthy persons ingested 0.5 g of ethanol/kg body weight initially and 0,15 g of ethanol/kg and hour for 12 hours. The fatty acids of plasma triglycerides were determined before and after ingestion of ethanol in persons fasting and nourished isocaloricaly, with and without blocking peripheral lipolysis by nicotinic acid and with addition of glucose. The fasting persons triglycerides fatty acids increased to 165.7 % of the initial value after 12 hours of ethanol ingestion, with a preferential increase in palmitic-, oleic- and stearic acid. When lipolysis in adipose tissue was blocked by 0.5 g of nicotinic adic/hour the triglyceride-fatty acids reached only 116.2% after 12 hours, with a decrease in oleic acid, which is present in adipose tissue to a higher degree than in plasma triglycerides. When nourished isocaloricaly, the enhancement of plasma triglyceride-fatty acids could not be suppressed by nicotinic acid. The changes in concentration and pattern of triglyceride-fatty acids announce that the fatty acids used for increased synthesis of triglycerides in fasting persons come from adipose tissue preferentially. In contrast ethanol-ingested hyperlipoproteinemia during ingestion of a food which cannot be suppressed by nicotinic acid, seems to orginate from fatty acids of the food and for de novo synthesis of fatty acids in the liver.