We investigated the effect of insulin on total and regional myocardial blood flow (MBF) and glucose uptake (MGU) in healthy subjects (50 ± 5 yr) by means of positron emission tomography (PET) with oxygen-15-labeled water (H2 15O) and fluorine-18 labeled fluorodeoxyglucose (18FDG) before and during physiological hyperinsulinemia (40 mU·min-1·m-2). Twelve male subjects were included in the study. During hyperinsulinemia, MBF increased from 0.91 ± 0.28 to 1.01 ± 0.31 ml·min-1·g-1 (n = 7 patients, P = 0.05; n = 112 regions, P <0.005). Intersubject variability ranged from -3.0 to +41%. MGU increased from 0.11 ± 0.08 (n = 5) to 0.56 ± 0.08 μmol·min-1·g-1 (P <0.0001, n = 7). MBF and insulin-mediated MGU were higher in the septum and anterior and lateral wall along short-axis regions of the heart. During hyperinsulinemia, MBF was also higher in the apex and midventricle compared with the base. MBF and MGU were positively correlated before (r = 0.66, P <0.0001) and during hyperinsulinemia (r = 0.24, P <0.05). These results provide evidence that insulin stimulates MBF in normal human hearts and appears to involve mainly those regions of the heart where insulin-mediated MGU is higher. Furthermore, regional distribution of insulin-stimulated MBF and MGU does not appear to be uniform across the left ventricular wall of healthy subjects.
|Journal||American Journal of Physiology - Endocrinology and Metabolism|
|Issue number||5 45-5|
|Publication status||Published - 2002|
- Diabetes mellitus
- Positron emission tomography
ASJC Scopus subject areas