Abstract
BACKGROUND: Cardiovascular disease (CVD) remains a key cause of mortality worldwide. Prior work has found that the association between stress and cardiovascular outcomes is moderated by emotion regulation (ER) and expressive suppression (i.e., emotion inhibition), which is linked with adverse outcomes (i.e., inflammation) in Western (Americans) but not Eastern (Japanese) populations. Existing cultural differences in biological stress responses and suppression use suggest that these factors may have different implications for CV outcomes. OBJECTIVE: We address this gap in the literature by examining if ER differentially moderates the relationship between stress and CVD risk between Japanese and American adults. METHOD: Participants were from the Midlife in Japan and Midlife in the United States studies and had complete biomarker and psychological data (Japanese: N = 315, M (age) = 59.22, 149 females; Americans: N = 524, M (age) = 51.98, 291 females). Stress was indexed using the perceived stress scale. Trait suppression and reappraisal were indexed using the Emotion Regulation Questionnaire. CVD risk was indexed using a composite score of body mass index, C-reactive protein, interleukin-6, systolic blood pressure, and high-density lipoprotein cholesterol ratio. RESULTS: Adjusting for age, sex, education, tobacco, alcohol, and prescription medication use, linear regressions revealed robust cultural differences among those with high suppression (r = -0.10 [-0.19, -0.01]). Higher stress was linked with higher CVD risk in Americans regardless of the level of reappraisal or suppression (r's > 0.11, p's < 0.07). In contrast, among Japanese with high suppression, higher stress was associated with lower CVD risk (r = -0.09 [-0.23, 0.05]). Higher stress was associated with greater inflammation among Japanese with lower suppression (r = 0.10 [-0.07, 0.28]). CONCLUSIONS: Consistent with prior work, these findings suggest that adaptive ER moderates the association between stress and CVD risk, and that suppression may not be universally 'maladaptive.' Results emphasize the importance of considering cultural context when assessing the impact of emotion suppression on health, which may help explain differences in CVD outcomes between individuals from Eastern and Western populations.