Glucose counterregulation, the physiological mechanisms that normally
very effectively prevent or correct hypoglycemia, involves both dissip
ation of insulin and activation of glucose counterregulatory (glucose-
raising) systems. Glucagon and epinephrine stand high in the hierarchy
of redundant counterregulatory factors. Hypoglycemia develops or prog
resses when both glucagon and epinephrine are deficient and insulin is
present despite the actions of other glucose-counterregulatory factor
s. Growth hormone (like cortisol) is demonstrably involved in defense
against prolonged (as opposed to short-term) hypoglycemia, but it is n
ot critical to recovery from even prolonged hypoglycemia or to the pre
vention of hypoglycemia after an overnight fast. Thus, growth hormone,
like cortisol stands lower in the hierarchy of the redundant glucose-
counterregulatory factors.