Role of catabolic hormones in the hypoketonaemia of injury.

Adaptation to fasting results in ketosis, protein conservation, and diminished energy requirements. To determine whether the attenuation of these responses following injury is due to an altered hormonal environment, we infused the catabolic hormones cortisol, glucagon, and adrenaline into seven fasting subjects for 72 h. Saline alone was administered during a comparable control period. Hormone infusion achieved blood levels typical of moderate injury and resulted in hypermetabolism, hyperglycaemia, hyperinsulinaemia, and marked suppression of fasting ketosis. The hypoketonaemia could not be accounted for by decreased precursor availability, accelerated ketone utilization or increased urinary excretion. The altered hormonal environment associated with critical illness attenuates fasting ketosis by limiting hepatic ketogenesis.