In healthy individuals, maintenance of a normal plasma glucose concentration depends upon:
●A normal endocrine system for integrating and modulating substrate mobilization, interconversion, and utilization
●Functionally intact enzymes for glycogenolysis, glycogen synthesis, glycolysis, gluconeogenesis, and utilization of other metabolic fuels for oxidation and storage
●An adequate supply of endogenous fat, glycogen, and potential gluconeogenic substrates (eg, amino acids, glycerol, and lactate)
Adults are capable of maintaining a near-normal blood glucose concentration, even when totally deprived of calories for weeks or, in the case of obese subjects, months . In contrast, healthy neonates and young children are unable to maintain normal plasma glucose concentrations after even a short fast (24 to 36 hours) and exhibit a progressive decline in plasma glucose concentration to hypoglycemic values [2,3].