Hypoketonemia and age-related fasting hypoglycemia in growth hormone deficiency

Body fuels were measured in 45 normal children and 17 growth hormone-deficient patients after 24 hours of fasting. After three months of therapy with human Growth Hormone (hGH) 16 of the patients were restudied. In all groups, β-hydroxybutyrate (BOHB) concentrations correlated inversely with age and with glucose concentrations. When adjusted for these factors, the concentrations of BOHB were significantly lower in the growth hormone-deficient patients than in the control children, before ( P < 0.01) as well as after therapy ( P < 0.01). Only the five youngest patients became hypoglycemic. During fasting, ketones, which serve as an alternative fuel for the brain, spare glucose. Thus, a shortage of ketones would compromise the ability of the patient to conserve glucose and predispose the patient to fasting hypoglycemia. Accordingly, we propose that hypoketonemia is a critical factor in the genesis of fasting hypoglycemia in growth hormone deficiency.