Depressed mood but not fatigue mediate the relationship between physical activity and perceived stress in middle-aged women

Objective: To determine whether depressed mood and fatigue mediate the relationships between physical activity, body mass index, menopausal hot flashes, and perceived stress. Method: This study is a secondary analysis of data obtained from a sub-sample of peri- and postmenopausal women (N=212) from the TREMIN Research Program on Women's Health. Results: The hypothesized mediational model was tested using path analysis within a structural equation modeling framework in Mplus Version 5.1. In unadjusted analysis, the relationships between physical activity, menopausal hot flashes, and perceived stress were mediated by depressed mood; fatigue mediated the relationships between hot flashes, body mass index, and perceived stress. When adjusting for age, insomnia, menopausal and hormone use status, the mediational effects of depressed mood oil stress remained significant only for physical activity, and fatigue mediated the relationship between hot flashes and stress. The adjusted model explained 70% of variance in perceived stress, 82% of variance in depressed mood, and 81% of variance in fatigue. Conclusion: Depressed mood may partially explain the relationship between physical activity and perceived stress in middle-aged women, however further studies are needed to corroborate causality. (C) 2009 Elsevier Ireland Ltd. All rights reserved.