This randomized, double-blind, prospective clinical trial aims to investigate the effect of remote ischemic preconditioning (RIPC) on myocardial protection in patients with type 2 diabetes mellitus undergoing elective coronary artery bypass graft (CABG) surgery. Perioperative myocardial injury remains a significant concern during CABG, particularly in high-risk patients such as those with diabetes. RIPC is a low-cost, non-invasive intervention that may reduce myocardial damage by enhancing ischemic tolerance through intermittent limb ischemia. Sixty patients aged 40-85 years with type 2 diabetes scheduled for isolated CABG will be randomized to either receive RIPC or standard care. RIPC will be applied through five cycles of upper limb cuff inflation and deflation prior to sternotomy. High-sensitivity troponin T levels will be measured at 24, 48, and 72 hours postoperatively to assess myocardial injury. Secondary outcomes include acute kidney injury (KDIGO classification), maximum vasoactive-inotropic score (VIS) during the first 72 postoperative hours, ICU and hospital length of stay. This study will provide insight into the cardioprotective role of RIPC in diabetic patients undergoing cardiac surgery.