Analysis of pancreatic volume in acute‐onset, slowly‐progressive and fulminant type 1 diabetes in a Japanese population

AIMS/INTRODUCTION: A decrease in the size of the pancreas is observed in islet autoantibody‐positive non‐diabetic donors and acute‐onset type 1 diabetes irrespective of the diabetes duration. Little is known, however, about the relationship between the size of the pancreas and type 1 diabetes subtypes, including fulminant type 1 diabetes. MATERIALS AND METHODS: We examined the pancreatic volume (PV) in 44 adult patients with type 1 diabetes (16 acute‐onset type 1 diabetes, 18 slowly progressive type 1 diabetes and 10 fulminant type 1 diabetes) and 39 age‐ and body mass index‐matched non‐diabetic controls. PV was measured by computed tomography. The ability to secrete insulin was assessed by stimulated C‐peptide after intravenous glucagon administration. RESULTS: PV was significantly correlated with bodyweight in both control participants and type 1 diabetes patients. The PV index (PVI; PV/bodyweight) was decreased by 39% in type 1 diabetes compared with that in controls. PVI was significantly decreased in acute‐onset type 1 diabetes patients and slowly progressive type 1 diabetes patients (both P < 0.0001), but not in fulminant type 1 diabetes patients (P = 0.10), compared with control participants. In cases patients with recent‐onset type 1 diabetes (0–7 days post‐diagnosis), PVI was significantly decreased in acute‐onset type 1 diabetes patients (n = 8, P = 0.0005), but not in fulminant type 1 diabetes patients (n = 7, P = 0.44), compared with controls. PVI showed no correlations with the diabetes duration, C‐peptide levels, glycated hemoglobin, glutamic acid decarboxylase autoantibody levels, serum amylase or daily total insulin dose in type 1 diabetes subtypes. CONCLUSIONS: The present results show that patients with acute‐onset type 1 diabetes and slowly progressive type 1 diabetes have small pancreases irrespective of the diabetes duration or C‐peptide levels. In contrast to earlier findings on acute‐onset type 1 diabetes, we found no reduction of PVI at the onset of fulminant type 1 diabetes.