Atorvastatin induces insulin sensitization in Zucker lean and fatty rats

Abstract

Background The 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors (‘statins’) have been implicated in preventing new onset type 2 diabetes, whereas the mechanism of this effect is not known. We investigated the effects of an HMG-CoA reductase inhibitor, atorvastatin, on insulin sensitization in Zucker lean and fatty rats. Methods and results In vivo studies of insulin sensitization were performed in chow fed Zucker lean and fatty rats treated with atorvastatin 50 mg/kg/day (ATORVA_50) and results were compared to Zucker lean and fatty rats treated with drug vehicle only (CONT). Additional Zucker lean rats were treated with an intermediate dose of atorvastatin 25 mg/kg/day (ATORVA_25). Treatment with atorvastatin resulted in a dose-dependent improvement in whole body insulin sensitivity in both lean and fatty rats, with an approximately two-fold increase in glucose infusion rate and glucose disposal (Rd) in ATORVA_50 versus CONT ( p < 0.01). Atorvastatin 50 mg/kg/day resulted in an increase in 2-deoxyglucose (2-DOG) uptake by skeletal muscles (approximately two-fold increase in 2-DOG uptake in quadriceps ( p = 0.06) and gastrocnemius ( p < 0.01)) in lean Zucker rats. Insulin-stimulated phosphorylation of Akt/PKB was significantly increased in skeletal muscle of ATORVA_50 versus CONT in both lean and fatty rats. Conclusion Atorvastatin induces insulin sensitization in Zucker lean and fatty rats. This may be a clinically important pleiotropic effect if confirmed in insulin resistant humans.