Mechanisms of Abnormal Glucose Metabolism During the Treatment of Acute Severe Asthma

Twenty-five patients with acute severe asthma were treated with oxygen, corticosteroids and either salbutamol or aminophylline by intravenous infusion. Blood glucose, plasma insulin and glucagon were measured during the first 24 hours of treatment. Salbutamol and aminophylline rapidly caused hyperglycaemia, accompanied by a rise in insulin and a fall in plasma glucagon. At first the increase in plasma insulin was insufficient to restore normoglycaemia, but by 24 hours homeostasis was restored. The early submaximal insulin response was attributed to the fasting caused by breathlessness. There was no evidence of an increase in hormone secretion caused by direct β2-adrenergic stimulation of the pancreatic islets. The effect of corticosteroids on blood glucose over the period of study was considerably less than the contribution of either salbutamol, or aminophylline.