3D implications of epicardial adipose tissue in the stratification of cardiac glucose uptake in type 2 diabetes: A [18F]FDG PET/CT study

Purpose: Epicardial adipose tissue (EAT) may reflect cardiovascular risk in type 2 diabetes (T2D). Thus, [18F]FDG PET/CT images of glucose energy metabolism following hyperinsulinemic-euglycemic clamp (HEC) were used to investigate whether the EAT associates to myocardial glucose uptake and clinical biomarkers promoting cardiovascular risk in T2D.Methods: Forty-seven T2D patients underwent cardiac [18F]FDG PET/CT examination after HEC. Scans were sorted into poor and good uptake groups according to the mean standardized uptake value (SUVmean). EAT was characterized from non-contrast CT images and included in comparisons. Both target-to-background ratios (TBR) and regional cardiac uptake in the 17-segment model were calculated and correlated to EAT-derived parameters. Results: TBR uptake in non-obese strongly associated to troponin levels (R = 0.8135), while EAT volumes were associated in obese (R = -0.7091) for similar troponin levels. Regarding segmental cardiac uptake, significant EAT volumes association (R = -0.5939) with additional clustering determined at-risk patients presented a 3D EAT thickness over 1.17 (cm). Dichotomizing EAT in thin and thick regions revealed thin EAT was associated to regional cardiac uptake in non-obese (R = -0.7172), whereas both thick (R = -0.6955) and total EAT (R = -0.7878) were associated in obese. Conclusion: 3D thin and thick regions in EAT allow cardiac glucose uptake stratification in T2D.Trial registration: NCT02248311