A shrinking pancreas predicts type 1 diabetes
11 April 2013 (10:20 AM) - Hot Topics
It has long been known that the exocrine pancreas shrinks in long-term type 1 diabetes. The reason for this (and for the decreased pancreatic weight also seen in type 2 diabetes) is unknown, although some have suggested that it might be due to loss of the trophic effect of insulin leaving the pancreatic islets. Two recent studies now show that it is already smaller at the onset of the disease, suggesting early involvement of the exocrine pancreas in the disease process, and identifying another early marker of pre-type 1 diabetes
In the first of the two studies, Alistair Williams and colleagues in Bristol estimated pancreatic volume using magnetic resonance imaging. In a previous study they confirmed autopsy studies by showing pancreatic volume to be decreased by 48% in those with >10 years of diabetes.
They now tested 24 healthy individuals (median age 27 yrs), and 20 adult patients with recently diagnosed type 1 diabetes (median age 27 yrs). The median duration of diabetes was 3.8 months. Pancreatic volume was estimated by an experienced radiologist who was blinded as to the diagnosis. After correction for body weight, pancreatic volume was reduced by 26% in those with recent onset diabetes .
Meanwhile, Campbell-Thompson and colleagues from Gainesville examined pancreases obtained via nPOD (network for Pancreatic Organ Donors). The study group consisted of 23 previously healthy donors, 8 people without diabetes but positive for single islet autoantibodies, and 20 with established type 1 diabetes. The mean pancreatic weights were 81.4 g for the controls, 61.3 for the antibody positive group, and 44.9 g for those with diabetes.
Pancreatic weight does vary within a healthy population but these studies, taken together, provide a striking indication that the disease process that eventuates in type 1 diabetes can produce pathophysiological changes in the exocrine pancreas before the onset of hyperglycaemia, opening up a fascinating new area for research.
The suggestion that such changes might be used to predict progression to type 1 diabetes appears more doubtful, although Williams et al point out that the MRI technique could prove more informative if used repeatedly in the same individual. Read more about the Exocrine pancreas in type 1
^ Williams AJK et al. Pancreatic volume is reduced in adult patients with recently diagnosed type 1 diabetes. J Clin Endocrinol Metab 2012;97(11):E2109-2113
^ Campbell-Thompson et al. Pancreas organ weight in individuals with disease-associated autoantibodies at risk for type 1 diabetes. JAMA 2012;30(22)2337-9