Yield of testing for micronutrient deficiencies associated with pancreatic exocrine insufficiency in a clinical setting: An observational study

BACKGROUND: Pancreatic exocrine insufficiency (PEI) can be difficult to diagnose and causes maldigestion symptoms and malabsorption. There has been a number of studies that have identified PEI associated micronutrient deficiencies (PEI-MD), however there is variation in both the frequency and type of PEI-MD reported, with the majority of studies including patients with PEI due to chronic pancreatitis (CP) or CP without PEI. There is a paucity of information regarding the prevalence of PEI-MD in patients with PEI without CP and the yield of testing for PEI-MD in a clinical setting in patients with suspected benign pancreatic diseases. AIM: To prospectively assess the yield and type of PEI–MD in patients with and without PEI secondary to benign pancreatic disease. METHODS: Patients investigated for maldigestion symptoms with Faecal Elastase-1 (FEL-1) and suspected or proven benign pancreatic disease were prospectively identified. At the time of FEL-1 testing, serum samples were taken for micronutrients identified by previous studies as PEI-MD: prealbumin, retinol binding protein, copper, zinc, selenium, magnesium and later in the study lipid adjusted vitamin E. FEL-1 was recorded, with a result < 200 µg/g considered diagnostic of PEI. Patients underwent computed tomography (CT) imaging when there was a clinical suspicion of CP, a new diagnosis of PEI recurrent, pancreatic type pain (epigastric abdominal pain radiating to back with or without previous acute pancreatitis attacks) or weight loss. RESULTS: After exclusions, 112 patients were recruited that underwent testing for FEL-1 and PEI-MD. PEI was identified in 41/112 (36.6%) patients and a pancreatic CT was performed in 82 patients. Overall a PEI-MD was identified in 21/112 (18.8%) patients. The yield of PEI-MD was 17/41 (41.5%) if PEI was present which was significantly higher than those without 4/71 (5.6%) (P = 0.0001). The yield of PEI–MD was significantly higher when PEI and CP were seen together 13/22 (59.1%) compared to CP without PEI and PEI without CP (P < 0.03). Individual micronutrient assessment showed a more frequent occurrence of prealbumin 8/41 (19.5%), selenium 6/41 (14.6%) and magnesium 5/41 (12.2%) deficiency when PEI was present (< 0.02). The accuracy of using the significant micronutrients identified in our cohort as a predictor of PEI showed a positive predictive value of 80%-85.7% [95% confidence interval (CI): 38%-100%] and a low sensitivity of 9.8%-19.5% [95% CI: 3.3%-34.9%]. CONCLUSION: Testing for PEI-MD in patients with suspected pancreatic disease has a high yield, specifically when PEI and CP are found together. PEI-MD testing should include selenium, magnesium and prealbumin.