Serum amylase during recovery from diabetic ketoacidosis

To elucidate the mechanism of the hyperamylasaemia which is often found in diabetic ketoacidosis, 9 patients who were admitted in this disease state were studied. Blood samples were taken every 4 hours for the first 24 hours and thereafter daily for 7 days. Serum amylase concentration increased gradually in all patients, from 256 (65-1155) U/1 at the initial sampling to a maximum of 1160 (210-2670) U/1 20-24 hours later (p. greater than 0.01), median values with 95% confidence limits. Simultaneously, plasma inorganic phosphate concentrations decreased from a median value of 1.35 mmol/l to 0.45 mmol/l (p less than 0.01), and a significant negative correlation was found between the changes in these parameters in 5 patients. Isoenzyme analysis in 8 of the patients showed that hyperamylasaemia was of the "salivary type" in two and of the "pancreatic type" in two. None of the patients had clinical signs of pancreatitis. It is concluded that in diabetic ketoacidosis, the increase in serum amylase concentration observed in all patients is closely related to the action of insulin in the majority of these, and some possible mechanisms are discussed.