Gastroenteritis-associated hyperamylasemia: Prevalence and clinical significance

Background: Serum amylase levels can be elevated in various pathological conditions. However, acute gastro-enteritis has not been widely recognized as a cause for hyperamylasemia. Patients and Methods: We conducted a retrospective study of amylase results for all patients hospitalized or discharged from the emergency department with a diagnosis of gastroenteritis from April through November 1999. Patients with other possible medical causes for elevated amylase levels were excluded. We also compared the clinical and laboratory parameters of hyperamylasemic vs normoamylasemic hospitalized patients with gastroenteritis. Results: A total of 1041 patients with acute gastroenteritis were identified. Serum amylase levels were determined in 701 patients and were abnormally elevated in 66 of them. In 15 patients, other possible causes of hyperamylasemia were present, and these patients were excluded. The mean serum amylase level among the remaining 51 patients (7.4% of the remaining 686 patients with gastroenteritis) was 1.32 of the upper normal level, with a range of up to 2.2 times the upper normal range. Clinicians tended to admit more hyperamylasemic patients than normoamylasemic patients (10 of 51 vs 65 of 635; P=.03, 1 sided). However, the course of gastroenteritis in the hospitalized hyperamylasemic patients did not differ significantly from that in the hospitalized normoamylasemic patients, as judged by the clinical signs and symptoms, laboratory results, length of hospital stay, and need for antibiotics. Conclusions: Gastroenteritis is associated with a mild to moderate elevation of serum amylase levels in a significant portion of patients and should be included in the differential diagnosis of hyperamylasemia. Such elevation, however, does not seem to bear clinical significance in terms of the severity of disease.