Low fecal elastase 1 levels do not indicate exocrine pancreatic insufficiency in type-1 diabetes mellitus

Objectives: On the basis of very low fecal elastase 1 and very high fecal fat estimations, it has been claimed that exocrine pancreatic insufficiency is frequent in diabetic patients, and that in up to 40% of the patients, pancreatic enzyme substitution would be indicated. Because this would affect millions of diabetic patients worldwide, we evaluated this suggestion by testing exocrine pancreatic function in type-1 diabetes using the criterion standard of exocrine pancreatic function tests, the secretin-cerulein test (SCT). The results of this test were then compared with those of fecal elastase 1 and fecal fat estimations. Methods: Thirty-three patients with type-1 diabetes mellitus underwent an SCT, a fecal fat estimation, and 2 fecal elastase 1 tests (using both monoclonal and polyclonal antibodies) to evaluate their exocrine pancreatic function. Results: The SCT results were abnormal in 11 of the 33 patients, who showed only mild to moderate exocrine pancreatic insufficiency, and the stimulated lipase secretion was never less than 10% of the level where pancreatic steatorrhea first occurs. The correlation between fecal elastase 1 and SCT showed much lower sensitivity, specificity, and positive and negative predictive values than did the correlation between SCT and fecal fat. Nonpancreatogenic steatorrhea was present in two thirds of the patients and was probably caused by bacterial overgrowth. Conclusions: Neither low fecal elastase 1 nor raised fecal fat levels reliably indicate exocrine pancreatic insufficiency in type-1 diabetes and therefore should not be used as an indicator for expensive pancreatic enzyme substitution.