Prolonged hyperamylasemia in patients with acute pancreatitis is associated with recurrence of acute pancreatitis

Serum amylase levels in patients with acute pancreatitis often remain or fluctuate above the upper normal limit for over a week. This study investigated the clinical characteristics of patients with prolonged hyperamylasemia and their prognoses, including recurrence. We retrospectively analyzed patients with first attacks of acute pancreatitis in a single center between March 2010 and December 2016. Patients were divided into 2 groups according to normalization of the serum amylase levels within a week. A total of 313 patients were enrolled after exclusion. The serum amylase levels were normalized within a week in 205 patients (65.5%, group 1) and elevated over a week in 108 patients (34.5%, group 2). Group 2 was more related to alcohol, higher computed tomography (CT) severity index, local pancreatic complication, and moderately severe pancreatitis than group 1 (P < .05). Recurrent pancreatitis developed significantly more in group 2 (39.8%) than in group 1 (19.5%) (P < .001). The factors related to recurrent pancreatitis were amylase group, sex, alcohol, CT severity index, necrosis, and severity of pancreatitis (P < .05). Multivariate analysis showed that recurrent pancreatitis was independently associated with amylase group (odds ratio [OR] 2.123, 95% confidence interval [CI]= 1.227–3.673, P = .007) and alcohol (OR 2.023, 95% CI 1.134–3.611, P = .017). In conclusion, prolonged hyperamylasemia over a week is associated with recurrence of acute pancreatitis.