GCG and Hyperglycemia: Hyperglycaemia is associated with adverse clinical outcomes in critically ill patients regardless of diabetes status.104–106 Proposed causes of stress-induced hyperglycaemia include excessive counterregulatory hormones (e.g. corticosteroids, glucagon, growth hormone, catecholamines) and release of the cytokines tumour necrosis factor (TNF)-alpha and interleukin (IL)-1.