Associação entre os níveis plasmáticos de adiponectina, leptina, insulina e TSH e a mortalidade em pacientes submetidos à cirurgia de revascularização do miocárdio

Abstract

Introduction: Cardiovascular diseases are the leading cause of death in Brazil and worldwide. Hormones can influence the outcomes of heart surgeries, including leptin, which affects the pathophysiology of cardiovascular diseases by promoting inflammation, oxidative stress, endothelial dysfunction, and cardiac remodeling. Adiponectin is involved in glucose homeostasis and is known for its antidiabetic, anti-atherogenic, and anti-inflammatory properties, supposedly having a cardioprotective effect. Insulin is the hormone that allows the myocardium to use glucose as an energy source, and diabetes mellitus is associated with higher cardiac mortality. Low TSH concentrations are predictive of postoperative cardiac events and cardiovascular mortality. Thus, these four hormones could serve as biomarkers for the outcomes of heart surgeries. Objectives: To analyze the serum concentrations of adiponectin, leptin, insulin, and TSH in patients who underwent coronary artery bypass grafting (CABG) surgery and correlate the hormonal data with the mortality rate within one year after surgery. Methodology: An observational and prospective clinical study conducted at the Pedro Ernesto University Hospital of UERJ, located in Rio de Janeiro. It involved 80 patients admitted to the cardio-intensive care unit for heart surgery with extracorporeal circulation. Results: The group of patients who died within one year after surgery showed the following statistical differences in hormone concentrations compared to the survival group: lower insulin (UI/ml) during the intraoperative period (27.81 ± 49.60; 86.31 ± 123.20; p-value = 0.0233), higher adiponectin (ng/ml) in the preoperative period (11706.3 ± 12597.2; 4419.2 ± 2988.4; p-value = 0.0061); intraoperative (6991.7 ± 6542.7; 3403.8 ± 2567.6; p-value = 0.0055); 24 hours postoperative (6715.8 ± 5085.0; 4673.6 ± 3978.2; p-value = 0.0092) and 72 hours postoperative (8857.3 ± 5765.8; 4673.6 ± 3978.2; p-value = 0.0006); and lower TSH (pg/ml) at 72 hours postoperative (24.4 ± 24.9; 216.2 ± 405.7; p-value = 0.0301). No significant difference was observed in leptin (pg/ml) concentrations during the evaluated periods. Conclusion: Leptin was not identified as a relevant marker for the risk of death or survival in patients undergoing CABG surgery. Increased insulin during the intraoperative period in the survival group may be associated with surgical stress and myocardial glucose metabolism to conserve oxygen consumption by the cardiac muscle. Lower TSH concentrations in the postoperative period of the death group may be related to a higher risk of adverse cardiac events and increased pro-inflammatory cytokines, which contributes to the risk of death. Among these hormones, our data suggest that adiponectin is the most relevant biomarker for the prognosis of patients undergoing CABG surgery. The higher adiponectin concentration in the death group may occur as a compensatory response, attempting to mitigate adverse factors in left ventricular function and promote glucose consumption by the myocardium. However, the role of adiponectin as a biomarker for worse cardiac prognosis needs further clarification.