Glucose intolerance in acute infections

To evaluate the influence of an infective agent, severity of infection and the age of the patient on infection-induced glucose intolerance, concentrations of fasting blood glucose, serum insulin (n = 31) and plasma glucagon (n = 22) were measured and the oral glucose tolerance test (OGTT) was carried out (n = 26) during acute and convalescence phases and after complete recovery in patients with viral (n = 17) or bacterial (n = 14) infections. Serum insulin was increased (P less than 0.001) but plasma glucagon was decreased (P less than 0.01) both during acute infection and the convalescence period. In the acute stage, 2-h values of blood glucose (P less than 0.01) and serum insulin concentrations (P less than 0.001) during OGTT were elevated. The index of insulin resistance (glucose x insulin) was increased by 33% during infection and by 28% during convalescence (P less than 0.001). The observed changes did not correlate with the severity of infection, were more pronounced in younger patients than in older ones and were not dependent on the infective agent. It is clinically important to recognize that the restoration of insulin sensitivity takes longer than the immediate recovery period from the infection.