Causes and diagnosis of pancreatic exocrine insufficiency

Causes of pancreatic exocrine insufficiency (PEI) include:

• pancreatectomyAustralasian Pancreatic Club Pancreatic Enzyme Replacement Therapy Guidelines Working Party, 2015
• chronic pancreatitis
• cystic fibrosisAustralasian Pancreatic Club Pancreatic Enzyme Replacement Therapy Guidelines Working Party, 2015
• obstruction of the main pancreatic duct caused by tumours
• reduced stimulation of pancreatic enzymes after gastric surgery or due to coeliac disease
• type 2 diabetesAustralasian Pancreatic Club Pancreatic Enzyme Replacement Therapy Guidelines Working Party, 2015
• inflammatory bowel disease.Australasian Pancreatic Club Pancreatic Enzyme Replacement Therapy Guidelines Working Party, 2015

PEI is identified based on the clinical context of the patient (eg patients with chronic pancreatitis), their symptoms (eg loose foul-smelling bowel movements, weight loss), and laboratory nutritional markers indicative of malnutrition (including blood concentration of vitamin A, vitamin D, vitamin E, magnesium, zinc, retinol binding protein, albumin and prealbumin, and international normalised ratio [INR]).

Testing for PEI is difficult because available tests have limited sensitivity and specificity; however, faecal elastase may be used. Faecal elastase has a sensitivity of approximately 40% in predicting PEIRoberts, 1986Australasian Pancreatic Club Pancreatic Enzyme Replacement Therapy Guidelines Working Party, 2015. If PEI is suspected despite a normal faecal elastase, blood nutritional markers can be used for assessmentLindkvist, 2012.

A therapeutic trial of pancreatic enzyme supplements can help to confirm the diagnosis of PEI; assess the effect of supplementation on the patient’s symptoms and nutritional status before deciding whether to continue therapy.