Gpx and MDA Oxidative Stress Markers and Severity of Depression as Predictives of Recurrent Stable Coronary Heart Disease. Summary of the Doctoral Thesis

Abstract

Background. Cardiovascular disease is a major cause of death globally, taking over one-third of all deaths worldwide. Multiple research results are confirming coronary heart disease and depression as highly comorbid, associating depression with an increased risk of incidents of coronary heart disease and vice versa, and depression is a strong predictor of coronary heart disease outcome. One of the mechanisms that may explain the interaction between depression and cardiovascular diseases is oxidative stress. Assessment of oxidative stress markers could modify risk stratification, diagnosis and prevention, and treatment of coronary heart disease and depression patients. Aim. To investigate the relationships between oxidative stress biomarkers, the prevalence of depression, and the risk of recurrent stable coronary heart disease. Methods. A retrospective case-control study, comparing patients with primary stable coronary heart disease with patients who have recurrent stable coronary heart disease by determining oxidative markers levels and depression signs and severity. Medical record analysis, structured interview, Geriatric Depression Scale, and blood samples to detect oxidative stress markers MDA and GPx were used as investigation methods. Results and discussion. 174 patients were included in this study – 49.4% with primary coronary heart disease and 50.6% with recurrent. The majority of the sample (83.9%) had high levels of MDA and for the rest of them, the MDA level was considered normal. MDA level was slightly higher in primary stable coronary heart disease group without depression. For the majority of the patients (72.4%) the GPx level was normal, for 17.8% it was high, and for 9.8% – low. Slightly more than half of the patients were experiencing depression (44.3% – mild and 6.9% – severe). Oxidative stress is a risk factor for coronary heart recurrence, especially in depressed patients. The prevalence of depression was higher in patients with recurrent coronary heart disease. Patients with both high GPx and depression had 10.6 times higher chances of recurrent stable coronary heart disease compared to those with normal GPx and without depression. Conclusions. Elevated GPx level was more common among patients with recurrent stable coronary heart disease. GPx levels were also higher in depressed patients with recurrent stable coronary heart disease. The majority of patients had high levels of MDA with higher rates in patients with primary stable coronary heart disease. More than a half of patients were experiencing mild or severe depression symptoms with higher rates among patients with recurrent stable coronary heart disease. Patients with high GPx and depression have higher chances of recurrent stable coronary heart disease. Increased MDA level is a risk factor for stable coronary heart disease in general but it does not link to depression severity and recurrence of stable coronary heart disease. Hence antioxidant enzyme GPx is a more significant marker of the risk of depression and recurrence of stable coronary heart disease.