In our study, we will propose a model, which would provide the basis to establish a marker for chronic reactivation of CMV and shed more light into the pathophysiology of CMV infection in patients with CAD in relation to GDF-15 and NrF2 and their implications on disease progression. Ultimately, this would then enable us to identify patients at risk and develop novel strategies for future treatment and prevention of heart diseases in our country. In light of our project research, the question arises whether telomere length could represent a marker of chronic CMV reactivation and uncertainty their length will be modified by the effect of DPP-4 or not?