TITLE:
Functional imaging of skeletal muscle glucose metabolism by 18FDG PET to characterize insulin resistance in patients at high risk for coronary artery disease
AUTHORS:
Ikuo Yokoyama, Toshiyuki Moritan, Yusuke Inoue
KEYWORDS:
Insulin Resistance; Glucose Metabolism; Skeletal Muscle; Coronary Risk Factor; Type II Diabetes Mellitus; Hypertension; Hyperlipidemia;18F-FDG; PET
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.5 No.12A,
December
31,
2012
ABSTRACT: Insulin
resistance is associated with several coronary risk factors and is thought to
play a critical role for the development of coronary artery disease. Insulin
resistance has several causes, including an impaired skeletal muscle glucose
utilization rate (SMGU), reduced peripheral blood flow, and altered fatty
tissue metabolism, with SMGU being considered the most important. Nonetheless,
insulin resistance has only been estimated by the glucose disposal rate (GDR)
in previous studies. Methods: Skeletal muscle metabolic imaging with 18FDG
and positron emission tomography (PET) was undertaken to measure SMGU during
hyperinsulinemiceuglycemic clamping in 22 normotensive type-2 diabetics under
no medications (T2- DM), 17 normotensive non-diabetic hypertriglyceridemics,
22 patients with hypertension, and 12 agematched controls. Whole body insulin
resistance was assessed by the GDR during hyperinsulinemiceuglycemic insulin
clamping. Results: The SMGU and GDR were significantly reduced in T2DM (32.1 ± 16.6
μmol/min/kg and 24.3 ± 13.0 μmol/min/kg, respectively), hypertriglyceridemics
(36.5 ± 13.5 μmol/min/ kg and 22.7 ± 8.07 μmol/min/kg respectively) and patients
with hypertension (35.4 ± 26.6 μmol/min/kg and 29.0 ± 9.90 μmol/min/kg, respectively)
compared with controls (72.2 ± 44.1 μmol/min/kg and 43.0 ± 22.9 μmol/min/kg, p
with T2DM, essential hypertension and hypertriglyceridemia. 18FDG PET functional imaging allows insulin resistance to be assessed.