Circulating cell‐free mitochondrial deoxyribonucleic acid is increased in coronary heart disease patients with diabetes mellitus

AIMS/INTRODUCTION Circulating cell-free mitochondrial deoxyribonucleic acid (ccf-mtDNA) is presumably derived from injured tissues or cells in the body and has been suggested to be potential biomarker in several diseases. The present study explored whether mtDNA could be used as a biomarker to evaluate disease in coronary heart disease (CHD) patients with or without diabetes mellitus (DM). MATERIALS AND METHODS A total of 50 CHD patients with type 2 diabetes, 50 CHD patients without type 2 diabetes, and 50 age- and sex-matched patients without CHD and DM (non-CHD-DM) were recruited. Ccf-mtDNA levels were assessed by measuring the nicotinamide adenine dinucleotide dehydrogenase 1 gene using quantitative real-time polymerase chain reaction. Receiver operating characteristic curve analysis of plasma mtDNA in CHD with or without DM was also determined. Multivariate logistic regression analyses were carried out to determine the correlation between the mtDNA levels and traditional CHD risk factors. RESULTS The plasma ccf-mtDNA levels were significantly elevated in CHD patients with DM compared with those without and non-CHD-DM. The area under the receiver operating characteristic curves of mtDNA in CHD patients with DM vs non-CHD-DM was 0.907%. Correlation analyses of the mtDNA levels and traditional CHD risk factors showed that the mtDNA levels were significantly correlated with fasting blood glucose in CHD patients with DM. CONCLUSIONS Ccf-mtDNA levels can be used as a biomarker in CHD patients with DM.