Objectives
Pancreatic necrosis may develop in moderately severe and severe acute pancreatitis (AP), and result in pancreatic exocrine insufficiency (PEI). The aim of this prospective study was to investigate development of PEI in patients recovering from the first attack of moderately severe or severe AP.

Materials and methods
Altogether 70 patients were recruited. The development of PEI was determined by measuring the fecal elastase-1 (FE-1) during the hospitalization time, and in the follow up period 1–2 months and 12 months after discharge. Persistent PEI was defined as FE-1 level below 200 µg/g at 12 months follow up.

Results
52 patients completed the study. The median age was 53 years, 65% were male, and 63% had severe AP. The most common etiology was alcohol (58%). After 12 months of discharge the FE-1 values were normal in 67% of patients, showed moderate insufficiency in 6% and severe insufficiency in 27% of patients. For pancreatic function there was a tendency to recover in one year follow up. However, four (17%) patients with initially normal FE-1 level developed persistent PEI, whereas three (25%) and eight (57%) patients with initially moderate or severe insufficiency, had persistent PEI at 12 months. During hospitalization new onset diabetes, extent (>50%) and anatomical site (body) of pancreatic necrosis, and low FE-1 level (median 28 µg/g, range 15–161) were predictive for persistent PEI at 12 months.

Conclusion
Around a third of patients with first attack of moderately severe or severe AP develop PEI.