Tight glycemic control may increase regenerative potential of myocardium during acute infarction.

Abstract

We analyzed the effects of tight glycemic control on regenerative potential of myocardium during acute myocardial infarction. Seventy-five patients with their first acute myocardial infarction undergoing coronary bypass surgery were studied: 25 patients with glycemia below 140 mg/dl served as the control group; hyperglycemic patients (glucose>140 mg/dl) were randomized to intensive glycemic control (IGC; n=20; glucose goal, 80-140 mg/dl), conventional glycemic control (CGC; n=20; glucose goal, 180-200 mg/dl), or glucose-insulin-potassium (GIK; n=10; glucose goal, 180-200 mg/dl) for almost 3 d before surgery, using insulin infusion followed by sc insulin treatment. During surgery, myocyte precursor cells (MPC) (c-kit/MEFC2/GATA4-positive cells), oxidation of MPC DNA (c-kit/8-hydroxydeoxyguanosine-positive cells), senescent MPC (c-kit/p16INK4a-positive cells), and cycling cardiomyocytes (Ki-67-positive cells) were analyzed in biopsy specimens taken from the peri-infarcted area. Before surgery, plasma glucose reduction was greater in the IGC group than in the CGC and GIK groups (P<0.001 for both). IGC patients had higher MPC (P<0.01) and cycling myocytes (P<0.01), as well as less oxidized (P<0.01) and senescent MPC (P<0.01) in peri-infarcted specimens compared with both CGC and GIK patients. Tight glycemic control, by reducing senescent MPC, may increase regenerative potential of the ischemic myocardium.