Clinical Approach to Diabetic Cardiomyopathy: A Review of Human Studies

Background: Diabetic Cardiomyopathy (DC) has been defined as a distinct entity characterized by the presence of diastolic or systolic cardiac dysfunction in a diabetic patient in the absence of other causes for Cardiomyopathy, such as coronary artery disease (CAD), hypertension (HTN), or valvular heart disease. Diabetes affects every organ in the body and cardiovascular disease accounts for two-thirds of the mortality in the diabetic population. Diabetes-related heart disease occurs in the form of coronary artery disease (CAD), cardiac autonomic neuropathy or DC. The prevalence of cardiac failure is high in the diabetic population and DC is a common, but underestimated cause of heart failure in diabetes. The strong association between diabetes and heart failure has fueled intense human and animal research aimed at identifying the mechanisms underlying diabetic myocardial disease. Despite significant progress made, the precise pathogenesis of diabetic Cardiomyopathy is yet to be clearly defined. Hyperglycemia, dyslipidemia and inflammation are thought to play key roles in the generation of reactive oxygen or nitrogen species which are in turn involved. Methods: We have reviewed the up-to-date scientific literature addressing these issues. Results: The myocardial interstitium undergoes alterations resulting in abnormal contractile function noted in DC. In the early stages of the disease, diastolic dysfunction is the only abnormality, but systolic dysfunction supervenes in the later stages with impaired left ventricular ejection fraction. Transmitral Doppler echocardiography is usually used to assess diastolic dysfunction, but tissue Doppler Imaging and Cardiac Magnetic Resonance Imaging are being increasingly used for early detection of DC. Diabetic patients with microvascular complications show the strongest association between diabetes and Cardiomyopathy, an association that parallels the duration and severity of hyperglycemia. Conclusion: The management of DC involves improvement in lifestyle, control of glucose and lipid abnormalities, together with treatment of hypertension and CAD, if present.