LAUSR

Increased frequency of exposure and affective responsivity to daily stressors are predictive of future cardiovascular disease (CVD)-related health outcomes and mortality. Profound stress system dysfunction is a hallmark characteristic of major depressive disorder (MDD), likely contributing to MDD-CVD comorbidity. Although a greater increase in negative affective responsivity (NA-R) to daily stress is evident in adults with MDD, whether this is linked to heightened cardiovascular stress reactivity remains unclear. We hypothesized that the slope of the positive relation between daily stress (quantified as both exposure frequency and NA-R) and the magnitude of acute stress-induced increases in heart rate (HR) and blood pressure would be steeper in adults with MDD compared to healthy non-depressed adults (HA). For 8 consecutive days, stressful events encountered in everyday life and while in naturalistic environments (e.g., argument with a partner) were assessed via an ambulatory daily diary in 40 HA (22±4 yrs; 24 female) and 40 adults with MDD (23±6 yrs; 32 female). On the last day of the daily dairy, HR (electrocardiogram) and mean arterial pressure (MAP; finger photoplethysmography) were measured during the cold pressor test (CPT). Daily stress exposure frequency was calculated as the percentage of days with at least one stressor reported across the 8-day protocol, and NA-R was calculated as the intra-individual slope of the change in negative affect on stressor days (at least 1 stressor) compared to negative affect on stressor-free days (no stressors). There were no group differences in the frequency of daily stressor exposure [36±26 (range: 0-100) HA v 41±23% (range: 0-100) MDD; p=0.32]; however, as expected, NA-R was greater in adults with MDD [0.23±0.10 (range: 0.09-0.52) HA vs 0.34±0.16 a.u. (range:0.09-0.71) MDD; p<0.01]. Daily stressor exposure frequency was not related to CPT-induced increases in HR or MAP in either group (all p>0.05). However, NA-R was positively related to both the CPT-induced increase in HR (β=35.18, SE=9.04, p<0.01) and MAP (β=20.20, SE=9.16, p=0.03) in adults with MDD but not in HA (HR: β=2.89, SE=21.23, p=0.89; MAP: β=1.70, SE=17.78, p=0.92). These data suggest that increased emotional vulnerability to common stressors that occur in naturalistic environments and as a part of day-to-day living is linked to potentiated cardiovascular stress reactivity in young adults with MDD, likely contributing to increased CVD risk. NIH R21MH123928 and R00 HL133414 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.