Serum concentrations of trypsin-like immunoreactivity and pancreatic isoamylase in insulin dependent diabetic patients.

Serum trypsin-like immunoreactivity and pancreatic isoamylase were measured in 302 insulin-dependent diabetic patients (166 men) using radioimmunoassay for the former and a photocolorimetric method for the latter. There was a significant correlation between the two enzymes (r = 0.67, p less than 0.0001) with lower concentrations of both trypsin-like immunoreactivity (208.8 micrograms/L) and pancreatic isoamylase (67.5 U/L) in diabetic patients as compared to controls (p less than 0.0001). Using multiple regression analysis, a statistically significant association was only apparent between enzyme concentrations and age at onset of diabetes (r = 0.31, p less than 0.0001). The results suggest that impaired exocrine pancreatic function may occur in an appreciable proportion of diabetic patients and also that a primary insult to the exocrine pancreas occurring at the time of endocrine injury may be a contributory factor.