Association between Striatal/Pancreatic Dopaminergic Ratio and Glycated Hemoglobin

Abstract

Abstract Context: 18F-FDOPA-based PET/CT imaging is used routinely in the management of various pancreatic diseases. It enters β-cells via the neutral amino acid transporter (LAT1/4F2hc). In patients with diabetes, an increase in blood glucose levels leads to a decrease in LAT1 expression. There is great interest in finding an association between glycated hemoglobin (HbA1c) level and pancreatic dopaminergic activity. Objective, Patients and Design: This study investigates the in vivo association between pancreatic dopaminergic activity and glycated hemoglobin (HbA1c) in both diabetic and non-diabetic patients. For this purpose, we defined the mean Striatal/Pancreatic Dopaminergic Ratio (SPDRmean) and conducted a retrospective analysis of all patients who underwent 18F-FDOPA-PET/CT of the head and body trunk from 01/01/2010 to 01/31/2021. HbA1c level at examination date was obtained. Pancreatic SUVmean, striatal SUVmean and pancreatic volume were computed. SPDRmean was calculated to correct for interpatient variability. Diabetic and non-diabetic patient groups were compared. In a linear regression model we determined the relationship between SPDRmean and HbA1c adjusted for age and sex. Results: We included 76 patients: 22 diabetics (29%), and 54 non-diabetics (71%). Between the diabetic and non-diabetic group there was a significant difference in age (p=0.006), pancreatic SUVmean (p =0.001) and SPDRmean (p<0.001). There was no significant difference in sex, striatal SUVmean, and pancreatic volume. For each SPDRmean unit increment HbA1c increases by 11.78 mmol/mol (95.0% CI 4.46-19.08). Conclusions: SPDRmean is highly associated with HbA1c in both diabetic and non-diabetic patients.