INS and type 2 diabetes mellitus: Early human studies by Shulman et al. showed that, under steady state plasma concentration of both glucose and insulin mimicking postprandial conditions, the mean rate of muscle glycogen synthesis accounted for most of the whole body glucose uptake and virtually all of non-oxidative glucose metabolism in both healthy and diabetic subjects (Shulman, 2000), with defects in muscle glycogen synthesis playing a major role in causing insulin resistance in type 2 diabetes (Shulman, 2000).