Association of the mitochondrial regulator PGC-1α with diabetes mellitus and myocardial ischemia–reperfusion injury in coronary artery bypass grafting

Objectives This study aimed to evaluate whether peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) could serve as a marker of myocardial ischemia by examining its association with cross-clamp time, which reflects the duration of ischemia, in patients undergoing coronary artery bypass grafting (CABG). Methods The study included 44 adult patients who underwent open-heart surgery at the Cardiovascular Surgery Clinic between June 2024 and December 2024. Serum samples separated from the blood collected after cross-clamping and at the pump outlet were analyzed in our hospital’s central laboratory for the PGC-1α study. PGC-1α levels were analyzed in terms of clinical parameters, lactate and high-sensitivity cardiac troponin T (hs-cTnT) levels of the patients. Results Preoperative PGC-1α levels did not differ significantly from postoperative levels (2.06 ± 5.75 vs. 1.43 ± 3.35, p = 0.608), whereas hs-cTnT levels increased significantly after surgery ( p < 0.001). Preoperative PGC-1α showed a moderate positive correlation with DM ( r = 0.366, p = 0.015) but no significant association with other clinical variables, including ICU duration ( r = 0.078, p = 0.616), glucose, or HbA1c (all p > 0.05). In the multivariable analysis, DM (odds ratio [OR] = 3.060, p < 0.05) and ICU duration (OR = 1.466, p < 0.05) were independently associated with PGC-1α, whereas preoperative glucose and HbA1c were not. ROC analysis demonstrated that hs-cTnT showed a significant discriminative ability for cross-clamp time in non-DM patients (AUC = 0.844, 95% CI: 0.684–1.000, p = 0.002), whereas this relationship was not observed in DM patients. In contrast, PGC-1α did not demonstrate a significant discriminative performance in either group (AUC = 0.300–0.535, p > 0.05). Conclusion PGC-1α was not associated with cross-clamp time or conventional markers of acute myocardial injury in patients undergoing coronary artery bypass grafting, indicating that it does not reflect ischemic duration. In contrast, hs-cTnT levels were significantly associated with the cross-clamp time in non-diabetic patients, whereas this relationship was not observed in diabetic individuals. The association of PGC-1α with diabetes mellitus and ICU duration suggests that it may reflect metabolic status rather than acute myocardial injury.