GCG and hyperinsulinism: Elevated VMH NE and 5HT activity produces a unique neuroendocrine profile characterized by increased plasma NE, epinephrine, glucagon, insulin, free fatty acid (FFA), triglyceride, and leptin levels, increased sympathetic/neuroendocrine drive for hepatic glucose output, adipose lipolysis, and vasoconstriction [11], as well as an increased insulin secretory response to glucose and hyperinsulinemia [11, 15] that, as a composite, represents the hallmark of the MS.