Duodenal calcium in chronic pancreatitis: is it of diagnostic value?

Chronic pancreatitis has been reported to be associated with an increased secretion of calcium in pancreatic juice. To determine whether estimation of duodenal calcium may be useful for diagnosing chronic pancreatitis, we compared duodenal calcium output in patients with chronic pancreatitis and in subjects without pancreatic disease, during intravenous infusion of secretion alone, with calcium, or with cholecystokinin-pancreozymin (CCK-PZ). Duodenal calcium output increased during infusion of both calcium and CCK-PZ to a similar extent in chronic pancreatitis and controls. Overall, duodenal output of chymotrypsin was markedly lower in chronic pancreatitis; however, chymotrypsin output increased in response to both intravenous calcium and CCK-PZ in both groups. Bilirubin output increased in both groups during calcium infusion, but this increase was significantly reduced in chronic pancreatitis; in contrast, CCK-PZ caused a similar increase in both groups. The high calcium output observed in hypercalcemia in the presence of low enzyme output suggests increased pancreatic secretion of enzyme-independent calcium in chronic pancreatitis. However, the difference is obscured by biliary calcium, which is secreted in much higher concentrations. Thus, duodenal calcium determination does not appear to be a useful diagnostic test in chronic pancreatitis.