Oxidative stress, depression, and risk of recurrence of stable coronary heart disease

Aim: The aim of the study was to investigate the relationships between a level of oxidative stress (OS), depression (D) and risk of recurrence of stable coronary heart disease (SCHD). Methods: A retrospective study was conducted on 174 participants, at the age 45+ years: 86 in-patients of the cardiology department with a recurrent SCHD and 88 in-patients of the cardiology department with primary SCHD. The severity of depressive symptoms was assessed using the long 30-item form of Geriatric Depression Scale (GDS), valid Latvian version of GDS-LAT. The blood samples were taken from each patient to measure oxidative stress parameters malondialdehyde (MDA) and glutathione peroxidase (GPx). Results: 83.9% of the sample had high level of MDA. In 72.4% of the sample the GPx level was normal, in 17.8% it was high and in 9.8% low. Slightly more than a half of the patients were experiencing depression (44.3% - mild D and 6.9% - severe D). GPx was found statistically differing between primary and recurrent SCHD (p = 0,003). Patients with both D and high GPx had 10.6 times higher chances of recurrent SHCD compared to those without D and normal GPx (p = patients with present D were experiencing both - high levels of MDA and GPx - more often than responders with no D, but this wasn't statistically significant [p = 0.51]). Conclusion: In the present study it was found that level of antioxidant (AO) enzyme GPx was significantly higher in depressed patients with recurrent SCHD compared to patients without D and to patients with primary SCHD and patients with both D and high GPx had higher chances of recurrent SCHD compared to those without D and normal GPx. It could be supposed that GPx is a more significant marker of risk of D and recurrence of SCHD. The high level of MDA in most of both (primary and recurrent SCHD) groups patients could evidence that increased OS is a risk factor for CHD in general. Monitoring OS biomarkers seems to be important in the management of SCHD comorbidity with D. Further studies are warranted to confirm these findings.