Diabetic cardiomyopathy in uncomplicated type 2 diabetes is associated with the metabolic syndrome and systemic inflammation

Excerpt

To the Editor: Even in the absence of hypertension or coronary artery disease, type 2 diabetic patients show myocardial structural and functional changes that are ascribed to so-called diabetic cardiomyopathy [1, 2]. Changes in cardiac energy metabolism, resulting from altered myocardial substrate supply and utilisation, in association with insulin resistance, may underlie this condition [3, 4]. In addition to linking insulin resistance, obesity, diabetes and cardiovascular disease, systemic inflammation has been implicated in cardiac functional and structural abnormalities [5, 6]. We hypothesised that cardiac functional changes in subjects with uncomplicated type 2 diabetes may be associated with a number of features of the metabolic syndrome, as defined by National Cholesterol Education Program guidelines [7], and markers of systemic inflammation. To this purpose, using magnetic resonance imaging, we determined cardiac systolic and diastolic function in 13 asymptomatic normotensive men with recently diagnosed (<5 years), well-controlled type 2 diabetes (mean age 56±6 years, HbA₁c 6.1±1.1%, mean diabetes duration 14 months [range 6–60 months]) and 13 age-matched controls [2]. Patients had no history or symptoms of cardiovascular disease and all subjects had a normal ECG. Exclusion criteria were microalbuminuria, retinopathy and autonomic neuropathy, as evaluated by Ewing’s cardiovascular tests, and the use of insulin or drugs other than oral hypoglycaemic agents. Plasma TNF-α and IL-6 concentrations and high-sensitivity C-reactive protein (CRP) were determined by ELISAs. Because of non-normal distribution, the inflammatory markers were logarithmically transformed. In addition, a systemic inflammation index was calculated as the sum of the logarithms of these inflammatory markers. The protocol conformed with the principles outlined by the Declaration of Helsinki and was approved by the local ethics committee. All subjects gave written informed consent. Comparisons between groups were made by unpaired two-tailed Student’s t-test. Results are presented as means±SD or as medians (interquartile range). …