Continuous nocturnal intragastric feeding, combined with frequent daytime feedings, has been reported to improve both linear growth and the metabolic abnormalities in patients with
glucose-6-phosphatase deficiency (Type I
Glycogen Storage Disease). However, elevated blood levels of
lactate have persisted. The present studies explore the relationship between blood
lactate concentrations in six patients with
glucose-6-phosphatase deficiency and variations in the rate and composition of the intragastric feeding. Blood
lactate and plasma
glucose concentrations were determined at rates of
dextrose administration ranging from 3-34 mg/kg/min.
Dextrose infusion at 100-200% of estimated normal
glucose production rates gave the best control of blood
lactate concentrations. Lower rates of
dextrose infusion resulted in significantly higher blood
lactate levels; higher rates produced
hyperglycemia, but no significant further reduction of blood
lactate. At identical rates of
glucose administration, a
dextrose-containing infant formula and a high
carbohydrate enteric feeding
solution gave no significant improvement in control of blood
lactate levels compared to
dextrose alone. Plasma
glucose levels fell more rapidly when intragastric feeding was stopped than after a mixed meal and
hypoglycemia appeared to develop before counter-regulatory responses could be mobilized. These observations may account for the increased susceptibility to symptomatic
hypoglycemia reported in patients treated with intragastric feeding.