Exocrine Pancreatic Insufficiency and Diabetes Mellitus

Gastrointestinal symptoms are common in patients with diabetes mellitus. One possible cause for these symptoms is exocrine pancreatic insufficiency, and although several hypotheses have been proposed to explain the aetiology, the precise pathophysiological mechanisms remain to be elucidated. The prevalence and the clinical importance of exocrine pancreatic insufficiency are debatable. Exocrine pancreatic insufficiency has been confirmed in insulin-dependent and non-insulin-dependent diabetes mellitus and might be related to diabetes mellitus duration. Considering the limitations of the tests, the test and patient selections in different studies have undoubtedly contributed to these conflicting results. Other likely causes are the underestimation of chronic pancreatitis and unrecognised pancreatogenic diabetes (type 3c diabetes mellitus). Because many studies have failed to relate the clinical symptoms of exocrine pancreatic insufficiency to a positive function test (e.g., faecal elastase-1 concentrations), and serum nutritional markers (as signs of malabsorption) were not been determined in all studies, the clinical importance of exocrine pancreatic insufficiency in patients with diabetes mellitus is also controversial. This review presents a critical analysis of the currently published literature on this topic, including the detailed limitations of the specific tests used to confirm exocrine pancreatic insufficiency.