Long-Term Prognosis of Autoimmune Pancreatitis in Terms of Glucose Tolerance

Objective: Glucose intolerance is often observed in autoimmune pancreatitis (AIP), although its long-term prognosis after steroid treatment (ST) is still unclear. Methods: A total of 47 patients with AIP were enrolled. On the basis of the change in hemoglobin A1c (Hb(A1c)) and the use of diabetic medication, prognosis was classified into 3 categories, namely, "improved,'' "aggravated,'' and "unchanged.'' The relation between the result of an initial glucagon tolerance test (Delta CPR) and the later use of insulin during maintenance ST was examined in 20 patients. The transitions of homeostasis model assessment beta cell and insulin resistance (HOMA-beta and HOMA-R) were analyzed in 16 patients. Results: Glucose tolerance was improved in 6 patients (13%), aggravated in 9 patients (19%), and unchanged in 32 patients (68%). All patients with Delta CPR less than 0.6 ng/mL were obliged to use insulin even after long-term observation, whereas all patients with Delta CPR more than 1.0 ng/mL were free from insulin therapy. Moreover, HOMA-beta showed significant improvement after ST (43.9% (sic)56.0% in median, P = 0.030), and HOMA-R showed significant aggravation (1.30 -> 1.78, P = 0.039). Conclusions: Glucose tolerance that is too severely damaged may not recover fully even after ST. Thus, ST should be performed to preserve insulin secretion at the early stage of AIP.