Negative Life Events as a Mediator of the Relationship Between Optimism and Cardiovascular Reactivity

Blunted cardiovascular reactivity (CVR) is associated with adverse health outcomes such as depression, obesity, and increased carotid intima-media thickness. Research indicates that significant negative life events (NLE) contribute to reduced CVR and related health issues, with individual perceptions and coping mechanisms playing a crucial role. Optimism, which is linked to fewer reported NLEs and better cardiovascular health, may improve coping processes, thereby reducing NLE's impact on CVR. This study investigated how NLEs mediate the relationship between optimism and CVR. The sample consisted of 199 adults recruited from universities in Ecuador. Participants completed psychological assessments prior to a controlled 45-min experimental session, which included baseline cardiac activity measurements followed by the PASAT task. The findings indicated that the number of NLEs mediates the relationship between optimism and diastolic blood pressure (DBP) reactivity, while optimism also exerts a direct effect on CVR beyond this mediation. Specifically, a significant inverse relationship was observed between the number of NLEs and DBP reactivity, alongside a positive relationship between optimism and DBP reactivity. Additionally, pessimism was associated with reduced systolic blood pressure (SBP) reactivity, though neither pessimism nor NLEs showed any effect on heart rate. These results highlight the protective role of optimism in modulating stress-related impacts on CVR and align with previous research suggesting that low CVR might be a result of maladaptive stress responses.