Author(s)

Ikuo Yokoyama, Toshiyuki Moritan, Yusuke Inoue

Department of Cardiovascular Medicine, Clinical Research Center, Sanno Hospital of International University of Health and Welfare, Tokyo, Japan.
Department of Clinical Engineering, Faculty of Medical Engineering, Suzuka University of Medical Science, Suzuka, Japan.
Department of Radiology, Kitasato University Graduate School of Medicine, Sagamihara, Japan.

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 < 0.01, respectively). In all groups studied, SMGU was significantly correlated with GDR (r = 0.76, p < 0.01) and GDR (F = 13.9) was independently related to SMGU (r = 0.81, p < 0.01). Conclusion: Insulin resistance is significantly associated with SMGU to a similar degree among patients with T2DM, essential hypertension and hypertriglyceridemia. ¹⁸FDG PET functional imaging allows insulin resistance to be assessed.

Insulin Resistance; Glucose Metabolism; Skeletal Muscle; Coronary Risk Factor; Type II Diabetes Mellitus; Hypertension; Hyperlipidemia;¹⁸F-FDG; PET

Yokoyama, I. , Moritan, T. and Inoue, Y. (2012) Functional imaging of skeletal muscle glucose metabolism by ¹⁸FDG PET to characterize insulin resistance in patients at high risk for coronary artery disease. Journal of Biomedical Science and Engineering, 5, 819-825. doi: 10.4236/jbise.2012.512A103.