Ketotic hypoglycaemia.

Ketotic hypoglycaemia is the most common form of childhood hypoglycaemia. This disorder classically manifests itself between the ages of 18 months and 5 years, and generally remits spontaneously before 8 or 9 years of age. A presumptive diagnosis is made by documenting a low blood sugar in association with ketonuria, ketonaemia and typical symptoms of hypoglycaemia. The definitive diagnosis is established by demonstrating an inability to tolerate a provocative ketogenic diet, or a fast. Susceptible or affected children develop severe hypoglycaemia and ketosis on this diet within 24 hours. Plasma alanine concentrations on either a normal or ketogenic diet were significantly lower in ketotic hypoglycaemic children compared with normal children. In contrast to adults, even normal children develop hypoglycaemia and ketonaemia when calorically deprived for relatively short periods of time (32 to 36 hrs).