Ethanol and its novel metabolites inhibit insulin action on adipocytes

The effects of ethanol, acetaldehyde, and the two novel metabolites of ethanol 2,3-butanediol and 1,2-propanediol on basal and insulin-stimulated adipocyte lipogenesis and glucose oxidation in vitro were investigated. Whereas ethanol and acetaldehyde inhibited both processes at concentrations far greater than those found in alcoholic subjects, the two diols were extremely potent inhibitors of basal and insulin-stimulated adipocyte metabolism at concentrations far below those observed in alcoholic subjects. The incorporation of labeled glucose into the fatty acid moiety and glucose oxidation were inhibited at lower concentrations (0.25 μM) than those required to inhibit the incorporation of the labeled glucose into glycerol. The diols are therefore potent inhibitors of basal and insulin-stimulated adipocyte metabolism. This effect may be relevant to the pathogenesis of insulin resistance in alcoholic subjects.