PROJECT SUMMARY Altered immune function, and in particular systemic inflammation, has been repeatedly associated with exposure to psychosocial stress and with increased risk for aging-related disease, but the mechanisms underlying these associations are unclear. The long-term goal of this research is to help elucidate the immune mechanisms linking psychosocial stress with aging-related and, in particular, cardiometabolic disease. The overall objective of this application is to determine the extent to which the levels of multiple immune mediators coordinately change in response to stress and predict cardiometabolic risk in perimenopausal women, an aging population characterized by high stress burden, declining estradiol levels, and dramatically increasing cardiometabolic risk. The central hypothesis is that stress during the perimenopause triggers systemic changes in the levels of multiple cytokines and other circulating molecules, and these systemic changes act in concert with declining estradiol levels to increase cardiometabolic risk. Consequently, the rationale of this application is that determining the levels of multiple circulating markers and their coordinated responses to stress during the perimenopause can yield novel, composite (multi-marker) predictors of cardiometabolic disease in aging women. The central hypothesis will be tested by pursuing two specific aims: 1) Determine how stress modulates immune mediators and pathways in aging perimenopausal women; and 2) Identify multi-marker predictors of cardiometabolic worsening during the menopausal transition. To accomplish these aims, the proposed research will use blood plasma previously collected – both at baseline rest and post-laboratory stress – in a well-characterized cohort of 151 perimenopausal women with already documented longitudinal measures of vascular and metabolic function. Plasma at both collection timepoints will be analyzed using quantitative cytokine arrays to profile 80 circulating markers involved in processes relevant for cardiometabolic disease, such as inflammation, metabolic regulation, and coagulation. The research proposed in this application is innovative because it will for the first time perform extensive, stress-stimulated cytokine profiling during the menopausal transition, a period characterized by high stress burden, changing hormonal and immune milieu, and increasing cardiometabolic risk, thus being uniquely positioned to address these critical relational gaps in knowledge. The proposed research is significant because it leverages already available biological material and extensive metadata to identify new molecular targets and risk markers and to ultimately enhance early interventions for cardiometabolic disease in aging women.