RESUMO
Background: Hyperglycemia is associated with an increased risk for death in acute coronary syndromes. This could be related to underlying glucose metabolism abnormalities or be caused by a counter-regulatory stress response. However, there is a paucity of data on the relationship between stress hormones, hyperglycemia, and clinical outcomes in myocardial infarction. Methods: Single-center, prospective, observational study. Patients admitted to the coronary care unit with a diagnosis of myocardial infarction were included. On admission, blood samples were obtained to measure serum glucose, cortisol, and catecholamines. A second sample was obtained at 8 AM after 48 h from admission. Results: There was a mild and positive correlation between serum cortisol and glucose (Spearman's rho = 0.24, p = 0.005), and no significant correlation was found between glucose and catecholamines. A similar correlation between cortisol and glucose among diabetics and non-diabetics was observed. Significantly higher serum cortisol and glucose levels were present in patients who developed heart failure or died during hospitalization. The association between glycemia and mortality lost significance in multivariate analysis, with a significant interaction term with cortisol (p = 0.003). Conclusion: Cortisol is a key responsible for stress hyperglycemia, and its deleterious effects on the cardiovascular system could be the cause for worst outcomes associated with hyperglycemia in ACS. Further research is warranted to ascertain this relationship and to investigate potential therapeutic targets.