The age of onset of diabetes and glutamic acid decarboxylase titer measured long after diagnosis are associated with the clinical stage of slow-onset type 1 diabetes

Aims: Diabetes mellitus is divided into 3 clinical stages: not insulin requiring, insulin requiring for control, and insulin requiring for survival. We investigated the clinical characteristics of patients with slow-onset type 1 diabetes (T1D) to examine which clinical factors influence the clinical stage. Methods: One hundred fifty patients with slow-onset T1D were divided into 3 groups based on disease stage, and clinical features were compared among these groups. The patients were also divided into 4 groups based on the age of onset and the glutamic acid decarboxylase antibody (GAD-Ab) titer, which was measured long after diagnosis (mean, 9.2 years). The frequencies of the 3 stages were compared among these 4 groups. Results: The age of onset and the log (GAD-Ab) titer differed significantly among the 3 stages. The number of patients not requiring insulin was significantly higher and the number of those requiring insulin for survival was significantly lower in the group in which the age of onset was >= 50 and the log (GAD-Ab) titer <0.6, while the opposite pattern was observed in the group in which the age of onset was <50 and the log(GAD-Ab) titer >= 0.6. Conclusions: Our results suggest that the combination of the age of onset and GAD-Ab titer measured long after diagnosis might predict the clinical stage of slow-onset T1D. (C) 2012 Elsevier Ireland Ltd. All rights reserved.