Stress-induced release of matrix metalloproteinase-9 in patients with coronary artery disease: The possible influence of cortisol.

Stress and inflammation are both important risk factors for coronary artery disease (CAD). However, the susceptibility to stress-induced inflammation and its determinants have been little explored in patients with CAD. Here, our aim was to study the stress-induced inflammatory response, more precisely the early release of matrix metalloproteinase (MMP)-9, and its association with cortisol response in patients with CAD. Sixty-four patients underwent a standardized laboratory stress test. The stress-induced release of MMP-9 was closely associated with the release of other neutrophil-associated proteins, MMP-8 and myeloperoxidase (MPO). It also showed a large variation among patients, as did cortisol. Twenty minutes after stress, a negative association between changes in MMP-9 and cortisol was seen (p<0.01). In vitro, dexamethasone reduced the IL-8-mediated release of MMP-9 from neutrophils, indicating that glucocorticoids may exert rapid effects on neutrophil activation. Further characterization of patients revealed that stress-induced release of MMP-9 was related to leukocyte telomere shortening and increased ultrasound-assessed plaque occurrence in the carotid arteries, but not to other characteristics such as age, gender or psychological background factors. The susceptibility to stress-induced release of MMP-9 may thus have impact on disease phenotype. Stress tests can be useful to identify CAD patients in need of novel prevention and treatment strategies.