[11C]5-hydroxy-tryptophan ([11C]5-HTP) PET of the pancreas has been shown to be a surrogate imaging biomarker of pancreatic islet mass. The change in islet mass in different stages of type 2 diabetes (T2D) as measured by non-invasive imaging is currently unknown. Here, we describe a cross-sectional study where subjects at different stages of T2D development with expected stratification of pancreatic islet mass were examined in relation to non-diabetic individuals. The primary outcome was the [11C]5-HTP uptake and retention in pancreas, as a surrogate marker for the endogenous islet mass.
We found that metabolic testing indicated a progressive loss of beta cell function, but that this was not mirrored by a decrease in [11C]5-HTP tracer accumulation in the pancreas. This provides evidence of retained islet mass despite decreased beta cell function. The results herein indicates that beta cell dedifferentiation, and not necessarily endocrine cell loss, constitute a major cause of beta cell failure in T2D.
§ Shared senior authorship
- Received November 25, 2016.
- Accepted February 16, 2017.
- © 2017 by the American Diabetes Association.