The Forgotten Role of Glucose Effectiveness in the Regulation of Glucose Tolerance

Glucose effectiveness (S _G) is the ability of glucose per se to stimulate its own uptake and to suppress its own production under basal/constant insulin concentrations. In an individual, glucose tolerance is a function of insulin secretion, insulin action and S _G. Under conditions of declining insulin secretion and action (e.g. type 2 diabetes), the degree of S _G assumes increasing significance in determining the level of glucose tolerance both in fasted and postprandial states. Although the importance of S _G has been recognized for years, mechanisms that contribute to S _G are poorly understood. Research data on modulation of S _G and its impact in glucose intolerance is limited. In this review, we will focus on the role of S _G in the regulation of glucose tolerance, its evaluation, and potential advantages of therapies that can enhance glucose-induced stimulation of glucose uptake and suppression of its own production in conditions of impaired insulin secretion and action.