HMGCR and Insulin resistance: Additionally, KDs, particularly VLCKD determines a reduction of insulin levels and a concomitant improvement in plasma lipids by inhibition of HMG-CoA reductase [88, 89]: in fact, the improvement of insulin resistance has positive effects on lipid metabolism through the action on 3-hydroxy-3-methylglutaryl coenzyme A reductase and striking effects on lipoprotein size and subclass particle concentrations [30].