This study explored relationships, before and after surgery, between perceived stress and the activity of white-blood cells (neutrophils) in 82 patients undergoing heart surgery involving cardiopulmonary bypass surgery (CPB).
On the evening before surgery and at follow-up, 6-weeks after discharge, patients completed self-administered standard psychological measures. Small peripheral blood samples were taken, from which neutrophil activity was quantified using nitro-blue tetrazolium (NBT) and luminoldependant chemiluminescence (phagocytic capacity).
There were consistent, statistically significant associations between stress and percent age NBT cells at baseline and at follow-up. Regression analysis showed that perceived stress was a predictor of neutrophil activity at follow-up suggesting that higher levels of stress are associated with higher levels of activity. Results from the phagocytic capacity data support and strengthen the NBT findings; in response to stimuli the phagocytic capacity of the neutrophils is reduced at baseline (high stress) and increased at follow-up (lower stress). Significant decreases were found on perceived stress, anxiety, depression, negative affect and health-related stress at follow-up. Patients' self-efficacy was high at baseline and remained high throughout the study.
Results highlighted a consistent, significant relationship between perceived stress and the ‘activity’ of neutrophils. The implications of this finding are worthy of exploration given that stressactivated neutrophils may adversely influence health outcomes.