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Objectives: The purpose of this study was to investigate the relationship between hepatic triglyceride content and both myocardial function and metabolism in type 2 diabetes mellitus (T2DM)., Background: Heart disease is the leading cause of mortality in T2DM. Central obesity and hepatic steatosis, both hallmark abnormalities in T2DM, have been related to increased risk of heart disease., Methods: Sixty-one T2DM patients underwent myocardial perfusion and substrate metabolism measurements by positron emission tomography, using [15O]water, [11C]palmitate, and [18F]-2-fluoro-2-deoxy-D-glucose. In addition, whole-body insulin sensitivity (M/I) was determined. Myocardial left ventricular function and high-energy phosphate metabolism were measured using magnetic resonance imaging and [31P]-magnetic resonance spectroscopy, respectively. Hepatic triglyceride content was measured by proton magnetic resonance spectroscopy. Patients were divided according to hepatic triglyceride content (T2DM-low5.56%)., Results: In addition to decreased M/I (p=0.002), T2DM-high patients had reduced myocardial perfusion (p=0.001), glucose uptake (p=0.005), and phosphocreatine/adenosine triphosphate (PCr/ATP) ratio (p=0.003), compared with T2DM-low patients, whereas cardiac fatty acid metabolism and left ventricular function were not different. Hepatic triglyceride content correlated inversely with M/I (Pearson's r=-0.620, p<0.001), myocardial glucose uptake (r=-0.413, p=0.001), and PCr/ATP (r=-0.442, p=0.027). Insulin sensitivity correlated positively with myocardial glucose uptake (r=0.528, p<0.001) and borderline with myocardial PCr/ATP (r=0.367, p=0.072), whereas a positive association was found between cardiac glucose uptake and PCr/ATP (r=0.481, p=0.015)., Conclusions: High liver triglyceride content in T2DM was associated with decreased myocardial perfusion, glucose uptake, and high-energy phosphate metabolism in conjunction with impaired M/I. The long-term clinical implications of hepatic steatosis with respect to cardiac metabolism and function in the course of T2DM require further study., (Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the effects of hyperglycemia due to partial insulin deprivation on myocardial triglyceride (TG) content and myocardial function in patients with type 1 diabetes., Research Design and Methods: Myocardial and hepatic TG content and left ventricular (LV) function were measured by magnetic resonance (MR) spectroscopy and MR imaging during optimal glucoregulation and after 24 h of partial insulin deprivation (n = 10)., Results: Mean insulin infusion rate was 45 +/- 5 units at baseline, whereas it was 27 +/- 5 units during hyperglycemia (per 24 h, P < 0.001). Plasma glucose levels increased from 8.4 +/- 0.6 to 15.9 +/- 0.8 mmol/l (P < 0.001), and plasma levels of nonesterified fatty acids from 0.31 +/- 0.05 to 0.46 +/- 0.07 mmol/l (P = 0.015). Hyperglycemia had no effects on myocardial or hepatic TG content and LV function., Conclusions: Short-term hyperglycemic dysregulation does not modulate myocardial or hepatic TG content or myocardial function, despite considerable metabolic adaptations.