Short-Term Hyperinsulinemia and Hyperglycemia Increase Myocardial Lipid Content in Normal Subjects

Increased myocardial lipid content (MYCL) recently has been linked to the development of cardiomyopathy in diabetes. In contrast to steatosis in skeletal muscle and liver, previous investigations could not confirm a link between MYCL and insulin resistance. Thus, we hypothesized that cardiac steatosis might develop against the background of the metabolic environ-ment typical for prediabetes and early type 2 diabetes: combined hyperglycemia and hyperinsulinemia. Therefore, we aimed to prove the principle that acute hyperglycemia (during a 6-h clamp) affects MYCL and function (assessed by 1H magnetic resonance spectroscopy and imaging) in healthy subjects (female subjects: n = 8, male subjects: n = 10; aged 28 6 5 years; BMI 22.4 6 2.6 kg/m2). Combined hyperglycemia (202.0 6 10.6 mg/dL) and hyperinsuline-mia (110.6 6 59.0 mU/mL) were, despite insulin-mediated suppres-sion of free fatty acids, associated with a 34.4 % increase in MYC