Abstract 19184: Depression Mediates the Relationship Between Physical Activity and Quality of Life Among Patients With Coronary Heart Disease

Background: Depression, a known comorbidity in coronary heart disease (CHD), is associated with adverse cardiac events, mortality, symptom burden, physical limitation, and poor quality of life (QOL). Evidence has shown that depression impedes self-care behaviors including, physical activity. Similarly, regular physical activity has been shown to lessen depressive symptoms and improve cardiovascular health. However, there is limited research to determine whether depressive symptoms mediate or moderate the association between physical activity and overall QOL in the older adult population living with chronic CHD. Hypothesis: Depression mediates the positive association between physical activity and QOL. Depression is a moderator of physical activity and QOL. Objectives: 1) To determine the direct effect of depressive symptoms on physical activity and QOL; 2) to investigate the mediating effect of physical activity and depressive symptoms on QOL; and 3) to test the moderating effect of depressive symptoms on physical activity and QOL. Methods: This cross-sectional study collected 20-year follow-up survey data from 126 survivors from the Heart and Soul prospective cohort study of people living with CHD. Mediation testing was conducted using the steps described by Baron and Kenny. Results: Physical activity significantly predicted QOL ( β =.133, p =.02) and significantly predicted depressive symptoms ( β =-.1918, p =.0002); depressive symptoms significantly predicted QOL( β =-0.762, p <.0001). After depression was added to the model, the relationship between physical activity and QOL was no longer significant, indicating a mediating effect. The average causal mediation effect was statistically significant (.1463, p =.0002). Depression was not a moderator of physical activity and QOL (p>.05). Conclusions: This study demonstrated that depression mediated the effect of physical activity on QOL. The findings underscore the importance of addressing physical activity and depressive symptoms in interventions to improve the overall well-being and quality of life of individuals living with chronic CHD.