Circulating Biomarkers and MicroRNAs in the Diagnosis, Prognosis and Treatment of Diabetic Cardiomyopathy-A Review
Author(s): Moorthy S, Koshy T, SrinivasanV, Silambanan S
Background: In the year 2015, diabetes mellitus resulted in 5 million deaths which were predicted to increase by 34% in 2030. The prevalence of cardiomyopathy in diabetics is 12% and is almost 22% in people over 64 years of age. Individuals with diabetes mellitus present with cardiomyopathy in the absence of hypertension, coronary artery disease, or valvular heart disease. Diabetic cardiomyopathy is a cardiac condition presenting with heart failure characterized by diastolic dysfunction and cardiac remodeling, in the absence of signs of coronary artery disease and hypertension. Glucotoxicity and lipotoxicity are the initiators of excessive autophagy, apoptosis, altered excitation contraction coupling and remodeling of extracellular matrix with excessive fibrosis in the myocardium. Since the condition is silent during early stage, use of novel biomarkers may be useful to identify patients who are at risk of cardiomyopathy. So far, only a few studies have explored miRNAs profile in patients with diabetic cardiomyopathy with inconsistent results. Biomarkers and microRNAs have been identified to diagnostic as well as prognostic indicators of the various stages of progression of diabetic cardiomyopathy. Cardiac microRNAs target mitochondrial dysfunction and free radical production thus they have a promising role in implementing targeted therapy in patients with diabetic cardiomyopathy. This review was undertaken to understand the roles played by various biomarkers and microRNAs in the diagnosis and prognosis and therapy in patients with diabetic cardiomyopathy.
Methodology: A literature search was done in PubMed, Embase, Cochrane Library, Pubmed Central, UpToDate, with the focus on biomarkers in Diabetic Cardiomyopathy. The articles selected included those on pathogenesis of diabetic cardiomyopathy, various diagnostic modes, the role played by biomarkers and miRNAs in the diagnosis especially in the early stage, in the prognosis that is markers representing the various stages of diabetic cardiomyopathy and also in targeted therapy. Since this was a review article ethics clearance was not obtained. This study did not receive funding from any government, private, national or international funding agencies.
Discussion: Diabetic patients without signs of overt heart failure are found to have diastolic dysfunction and subclinical systolic dysfunction in most of the situations. The abnormalities in diastolic function or wall thickness reflect the changes of diabetic cardiomyopathy. At present, screening of asymptomatic diabetic cardiomyopathy for features of heart failure is not possible. This can be achieved by measuring circulating biomarkers and microRNAs. This results in reduction of the morbidity by early introduction of cardiac rehabilitation to diabetic individuals who are likely to develop cardiomyopathy in the coming years.