Vodka and wine consumption in a swine model of metabolic syndrome alters insulin signaling pathways in the liver and skeletal muscle

BackgroundThe purpose of this study was to examine the effects of alcohol in the context of metabolic syndrome on insulin signaling pathways in the liver and skeletal muscle.MethodsTwenty-six Yorkshire swine were fed a hypercaloric, high-fat diet for 4 weeks then split into 3 groups: hypercholesterolemic diet alone (HCC, n = 9), hypercholesterolemic diet with vodka (HCVOD, n = 9), and hypercholesterolemic diet with wine (HCW, n = 8) for 7 weeks. Animals underwent intravenous dextrose challenge before euthanasia and tissue collection.ResultsHCC, HCVOD, and HCW groups had similar blood fasting glucose levels, liver function test, and body mass index. Thirty and 60 minutes after dextrose infusion, HCVOD and HCW groups had significantly increased blood glucose levels compared with the HCC group. The HCW group had significantly increased levels of insulin compared with the HCC group. Immunoblotting in skeletal muscle demonstrated that alcohol up-regulates p-IRS1, IRS2, AKT, AMPKα, PPARα, Fox01, and GLUT4. In the liver, HCW had up-regulation of AKT, AMPKα, and GLUT4 compared with HCC. Skeletal muscle immunohistochemistry demonstrated increased sarcolemmal expression of GLUT4 in both alcohol groups compared with HCC.ConclusionModerate alcohol consumption in a swine model of metabolic syndrome worsens glucose metabolism by altering activation of the insulin signaling pathway in the liver and skeletal muscle.