Physical activity and depression symptoms in women with chronic illness and the mediating role of health-related quality of life.

BACKGROUND:The aim of this study was to determine the impact of physical activity on depression symptom severity in women 45 years and older with a chronic illness diagnosis, and explore relations between physical activity and psychological and health-related characteristics predicting depression symptoms. METHODS:1932 women diagnosed with one of five chronic illnesses: asthma, depression, diabetes, osteoarthritis, or osteoporosis participated in a sub-study of the 45 and Up Study-a cross-sectional study of people aged 45 years and older. The survey included items measuring demographics, depression symptoms, health-related quality of life (HRQoL), health-related hardiness, sleep quality, and health behaviours, such as physical activity. RESULTS:A multiple regression model explained 43% of the variance in depression symptoms (R2 = 0.43, F (18) = 61.72, p < .001); intensity of physical activity was a significant predictor of depression symptoms (p < .001), and HRQoL was found to explain the most variance (B = -10.00) in depression symptoms. Mediation analysis confirmed that HRQoL partially mediated the relation between physical activity and depression symptoms; however, the effect was very small. LIMITATIONS:Cross-sectional data and self-report measures limit the implications of the findings. CONCLUSION:Women with chronic illness engaging in more vigorous physical activity had less severe depression symptoms. Findings suggest that improving HRQoL is critical to the prevention and management of depression symptoms in women with chronic illness. Psychological and health-related factors that influence HRQoL, such as sleep quality and health-related hardiness, are important clinical considerations for health practitioners.