Evaluation of new exocrine pancreatic function tests and their application to clinical research I. Aging and exocrine pancreatic function as evaluated by fecal chymotrypsin activity

To examine the relationship between aging and pancreatic exocrine function, fecal chymotrypsin activity (FCA) was measured by a photometric method in 62 healthy controls (20 to 87 years old, with a mean age of 51.0), 43 patients with non-pancreatic diseases ( 31 to 83 years old, with a mean age of 55.7), 40 controls with no known digestive diseases in an old-age home (63 to 92 years old, with a mean age of 77.6) and 22 patients with chronic pancreatitis (17 to 72 years old, with a mean age of 52.9).Pancreatic exocrine function decreased significantly with aging as indicated by: (a) a significant inverse correlation between aging and FCA in the 62 healthy controls (r=-0.56, p<0.001), in the 43 patients with non-pancreatic diseases (r=-0.58, p<0.001), and in the 40 controls in an old-age home (r=-0.52, p<0.001): and (b) a significantly lower FCA in the 21 healthy controls over 65 years of age (designated as B-group of healthy controls) than the 41 healthy controls under 65 years of age (designated as A-group of healthy controls).The 40 controls in an old-age home showed significantly lower FCA than the B-group of healthy controls. This result was ascribed to the fact that the former group comprised significantly older subjects than the latter.No significant difference was found in FCA between patients with chronic pancreatitis and B-group of healthy controls as well as controls in an old-age home. When the mean -2SD of the A-group of healthy controls was set as the lower limit of normal, 59.1 percent of patients with chronic pancreatitis, 52.4 percent of B-group healthy controls and 62.5 percent of controls in an old-age home showed abnormally low levels of FCA. This result indicates that the FCA value should be carefully interpreted with respect to the age of the patient before making the diagnosis of pancreatic disease.