Sedentary behavior, sleep, quality of life, and subjective memory function in middle-aged and older adults

Sedentary behavior (SB) has been associated with poor health outcomes. Middle-aged and older adults often spend more time in SB compared to younger adults. Little is known about the association of SB with health-related quality of life (HRQOL) and subjective memory function. Poor sleep quality is also prevalent among middle-aged and older adults. However, no known study has examined the mediating role of sleep quality in the association of SB with HRQOL and subjective memory function. Study 1 examined the relationship between objective measurement of SB and HRQOL. Cross-sectional analyses included 1,353 US middle-aged and older adults from the 2005-2006 National Health and Nutrition Examination Survey. The results showed that higher SB percentage was significantly associated with poor general health, more physically unhealthy days, and more activity limitation days. However, SB hours related to better general health and fewer physically unhealthy days. Neither SB percentage nor SB hours were related to mentally unhealthy days. Sleep quality mediated the association of SB percentage to general health, physically unhealthy days, and mentally unhealthy days. Study 2 identified different types of SB and examined their separate associations with HRQOL and subjective memory function. Cross-sectional analyses recruited 363 US middle-aged adults from Amazon MTurk. Exploratory factor analysis categorized ten different sedentary activities into Common Engaging SB, High Engaging/Leisure SB, and Less Engaging/Passive SB. Findings suggested that Common Engaging SB was adversely associated with HRQOL and subjective memory function, whereas High Engaging/Leisure SB was positively related to HRQOL, but not subjective memory function. Further, sleep quality appeared to mediate the association of Common Engaging SB and High Engaging/Leisure SB to HRQOL. Future research should examine these associations by conducting longitudinal studies and comparing objective and subjective measurements of SB. Moreover, objective measurements of sleep quality, HRQOL, and memory performance are needed to eliminate recall bias associated with self-reported data. Reducing sitting time, particularly Common Engaging SB, could be a useful strategy by which to improve HRQOL and subjective memory function. Health promotion programs might help to promote mentally engaging activities because such activities might increase individuals’ HRQOL. Interventions are needed to raise public awareness regarding the importance of sleep quality