Determination of α-amylase in serum and urine of subjects with a low bicarbonate concentration in the duodenal aspirate after secretin stimulation

Abstract

A group of 23 patients with suspected pancreatic insufficiency having a maximal bicarbonate concentration of less than 70 mmole/1 in the duodenal aspirate after secretin stimulation was compared with normal subjects with regard to serum α-amylase values and urinary α-amylase excretion. The α-amylase was measured with a new, accurate and sensitive chromogenic method (Phadebas Amylase Test, Pharmacia, Sweden). Both the mean serum α-amylase values and the urinary excretion of α-amylase during 2 h after intake of 500 ml of water were low in the pathological series and differed highly significantly from the values of the control groups. Amylase clearance was significantly decreased in the pathological series, but the total overlap of the results precludes the use of serum α-amylase measurements as a diagnostic aid in pancreatic insufficiency. By contrast, the values for the urinary excretion of α-amylase showed little overlap of the results of the two series of subjects (only one value in the pathological series was above the suggested normal lower limit). This simple test, which can be made without a specialized gastroenterology department, could serve as a valuable aid in the laboratory diagnosis of pancreatic insufficiency. The results also indicate that at least 72% of the normal urinary α-amylase found in the water-load test is of pancreatic origin.