title: Regional myocardial blood flow and glucose utilization during fasting and physiological hyperinsulinemia in humans.
abstract: 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 (H(2)(15)O) and fluorine-18 labeled fluorodeoxyglucose ((18)FDG) 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 micromol.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.
authors.affiliation: Medical Research Council Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London W12 ONN, United Kingdom.
authors.forename: Patricia
authors.initials: P
authors.lastname: Iozzo
authors.forename: Panithaya
authors.initials: P
authors.lastname: Chareonthaitawee
authors.forename: Marco
authors.initials: M
authors.lastname: Di Terlizzi
authors.forename: D John
authors.initials: DJ
authors.lastname: Betteridge
authors.forename: Ele
authors.initials: E
authors.lastname: Ferrannini
authors.forename: Paolo G
authors.initials: PG
authors.lastname: Camici
mesh_terms: D003326:Coronary Circulation / Q000502:physiology*; D005215:Fasting / Q000502:physiology*; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000493:pharmacokinetics*; D015309:Glucose Clamp Technique; D006801:Humans; D006946:Hyperinsulinism / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose