The relationship between pancreatic atrophy after steroid therapy and diabetes mellitus in patients with autoimmune pancreatitis

Abstract

Background/objectives: Many patients with autoimmune pancreatitis (AIP) have an association with diabetes mellitus. It has not been clarified whether steroid therapy for AIP improves or worsens the condition of diabetes mellitus. The aim of this study was thus to investigate the relationship between pancreatic atrophy after steroid therapy and the clinical course of diabetes.

Methods: Thirty-one AIP patients, who were treated by steroid therapy, were included in this study during December 2005 to March 2013. Pancreatic atrophy 6 months after the beginning of steroid therapy was defined to be present when the width of the pancreatic body was less than 10 mm. The relationships between pancreatic atrophy and patient characteristics as well as the course of diabetes were examined.

Results: Steroid therapy was effective in all treated patients. Pancreatic atrophy was observed in 12 patients and not in 19 patients after the steroid therapy. AIP patients with pancreatic atrophy showed higher incidences of diabetes mellitus (p = 0.001, 9/12 vs. 2/19), diabetes control worsening (p = 0.007, 7/12 vs. 2/17), and new onset of diabetes (p = 0.02, 5/7 vs. 1/18) than those without atrophy. It was not associated with gender, other organ involvement, pattern of pancreas swelling (diffuse/focal), serum IgG4 level, alcohol intake, and pancreatic calcification on CT. Patients with new onset of diabetes needed insulin therapy, even in the maintenance therapy of AIP.

Conclusions: AIP patients with pancreatic atrophy after steroid therapy have a high incidence of diabetes mellitus. New onset of diabetes is closely associated with pancreatic atrophy after steroid therapy.

Keywords: Autoimmune pancreatitis; Diabetes; Insulin therapy; New onset of diabetes; Pancreatic atrophy; Steroid therapy.