Fasting energy utilization in the smaller of twins with epinephrine-deficient hypoglycemia

Glucose infusion paradoxically accelerates degradation of adenine nucleotide in working muscle of patients with glycogen storage disease type VII

We investigated the effect of glucose infusion on adenosine triphosphate degradation in skeletal muscle of patients with glycogen storage disease type VII. Three patients and six healthy subjects exercised on a bicycle ergometer twice, once with 20% glucose infusion and once with saline infusion. The glucose infusion increased plasma glucose levels to 170 to 182 mg/dl and serum insulin levels to 30 to 50 microU/ml, while it markedly decreased plasma free fatty acid levels. The exercise-induced increases in plasma ammonia, inosine, and hypoxanthine were much larger with glucose than with saline infusion in the patients. Urinary excretion of inosine and hypoxanthine with glucose infusion was twice as high as that with saline infusion. No such differences were present between glucose and saline infusion in the healthy subjects. Glucose infusion therefore accelerates the energy crisis in working muscle of patients with glycogen storage disease type VII, probably due to a decrease in fatty acid utilization.

Depletion of hepatic glycogen in the hypoglycaemia of fatal childhood diarrhoeal illnesses

To determine whether depletion of liver glycogen or accumulation of liver fat (steatosis) was associated with the development of hypoglycaemia in children with fatal diarrhoeal illnesses, a case-control study was carried out comparing 17 children who had blood sugars less than or equal to 30 mg/dl with 17 age matched control children who had blood sugars greater than or equal to 59 mg/dl. The most common causes of diarrhoea in the hypoglycaemic children were Shigella sp. and Vibrio cholerae. The mean duration of diarrhoea before admission for the hypoglycaemic children, 7.8 d, was shorter than the 20.7 d for the controls (P less than 0.01). Most children in both groups showed signs of malnutrition, metabolic acidosis, and pneumonia. Liver specimens were obtained at post-mortem examination and stained with haematoxylin and eosin for general assessment and with periodic acid-Schiff stain for glycogen. Glycogen depletion was detected in 9 hypoglycaemic children and in only 3 control children (P less than 0.05). Hepatic steatosis, on the other hand, occurred with equal frequency in both groups but was associated with severe malnutrition in the hypoglycaemic patients (P less than 0.05). This result suggested that hypoglycaemia develops during acute diarrhoeal illnesses because gluconeogenesis fails to maintain the blood sugar concentration after depletion of liver glycogen. Frequent feeding of children with diarrhoea might help to prevent this complication.