Positive Health Online

Abstract

BENSCHOP and colleagues, The National Jewish Medical and Research Center, Denver, Colorado, USA performed a meta-analysis in order to describe the relationships between cardiovascular and natural killer (NK) cell number changes and acute psychological stress in women .

Background

Methodology

Data from 8 studies were analysed. A total of 128 healthy women, 85 aged 18-45 years and 43 aged 49-87 years were subjected to a speech stressor (N = 80) or a mental effort stressor (N = 48), either mental arithmetic or the Stroop test. Correlations between NK cell number changes, systolic (SBP) and diastolic (DBP) blood pressure and heart rate (HR) were computed. Meta-analysis programmes studied correlations across studies and examined whether correlations changed with stressors or age.

Results

In all the studies there were significant increases over the baseline observed for each variable. Across the studies, the mean weighted r between changes in HR, DBP and SBP was medium (rw = 0.25) to large (rw = 0.64). There was a medium to large average correlation between HR and NK changes (rw = 0.37), whereas average correlations of NK cell number changes with blood pressure changes were small to medium (rw < or = 0.23). The correlations between NK cell number changes and cardiovascular variables were homogeneous across the studies; however, mutual correlations between cardiovascular variables were heterogeneous. One moderator variable became visible: correlations between HR and DBP reactions were larger in studies with older than younger subjects.

Conclusion

Changes in NK cell and HR responses induced by acute stress in women are regulated to a certain extent by the same mechanisms. Neither the stressor nor age appear to be very important in considering the correlations between NK cell and cardiovascular changes. This meta-analysis integrates data, which can be used as reference material for future studies, regarding NK cell and cardiovascular responses in women.

References

Benschop RJ et al Cardiovascular and immune responses to acute psychological stress in young and old women: a meta-analysis. Psychosom Med 60(3): 290-6 May-Jun 1998.