Aims/hypothesis: Loss of pancreatic beta cell mass and function leads to the development of diabetes mellitus. Currently there is no technical way to non-invasively image islet function and mass. Murine models suggest that islets are highly vascularised organs that make a significant contribution to the total pancreatic blood flow. The current study was undertaken to test with arterial spin labelling (ASL) magnetic resonance imaging if islet mass and/or stimulation of human pancreatic islets by hyperglycaemia can differentially increase whole-pancreas perfusion, thereby distinguishing non-diabetic from type 1 diabetic patients.
Methods: We assessed pancreatic blood flow using ASL at baseline, during a hyperglycaemia clamp study (glucose at 11 mmol/l) and during recovery to euglycaemia.
Results: Seventeen healthy volunteers and seven type 1 diabetic patients were studied. In healthy volunteers we observed no change in pancreatic blood flow during the three phases of the study. A trend for an increase in blood flow was observed in the two control tissues, the liver and kidney. Similarly, there was no significant difference in blood flow during the three stages (baseline, hyperglycaemia and recovery) in diabetic patients and there was no significant difference observed between diabetic patients and normal volunteers.
Conclusions/interpretation: Our data suggest that in humans neither increased demand nor islet mass has a substantial influence on pancreatic perfusion. It is possible, however, that the current state-of-the art imaging technology employed in this study might not be sensitive enough to distinguish between a true effect and noise.
Trial registration: ClinicalTrials.gov NCT00280085.