Sitting Time and All-Cause Mortality Risk in 222 497 Australian Adults

Sydney School of Public Health, University of Sydney, Sydney, NSW 2006, Australia.
Archives of internal medicine (Impact Factor: 13.25). 03/2012; 172(6):494-500. DOI: 10.1001/archinternmed.2011.2174
Source: PubMed

ABSTRACT Prolonged sitting is considered detrimental to health, but evidence regarding the independent relationship of total sitting time with all-cause mortality is limited. This study aimed to determine the independent relationship of sitting time with all-cause mortality.
We linked prospective questionnaire data from 222 497 individuals 45 years or older from the 45 and Up Study to mortality data from the New South Wales Registry of Births, Deaths, and Marriages (Australia) from February 1, 2006, through December 31, 2010. Cox proportional hazards models examined all-cause mortality in relation to sitting time, adjusting for potential confounders that included sex, age, education, urban/rural residence, physical activity, body mass index, smoking status, self-rated health, and disability.
During 621 695 person-years of follow-up (mean follow-up, 2.8 years), 5405 deaths were registered. All-cause mortality hazard ratios were 1.02 (95% CI, 0.95-1.09), 1.15 (1.06-1.25), and 1.40 (1.27-1.55) for 4 to less than 8, 8 to less than 11, and 11 or more h/d of sitting, respectively, compared with less than 4 h/d, adjusting for physical activity and other confounders. The population-attributable fraction for sitting was 6.9%. The association between sitting and all-cause mortality appeared consistent across the sexes, age groups, body mass index categories, and physical activity levels and across healthy participants compared with participants with preexisting cardiovascular disease or diabetes mellitus.
Prolonged sitting is a risk factor for all-cause mortality, independent of physical activity. Public health programs should focus on reducing sitting time in addition to increasing physical activity levels.

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    • "It is estimated to cause around 21–25% of breast and colon cancer burden, 27% of diabetes, and about 30% of ischaemic heart disease burden [3]. It was found to be responsible for 1 in 10 deaths in the United States [4], and in a recent large study of Australian adults it was consistently associated with all-cause mortality across a number of different demographic and behavioural factors, including physical activity itself [5]. In Australia, about 16,000 people die prematurely every year because they are not active enough. "
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    ABSTRACT: Background. Measures of screen time are often used to assess sedentary behaviour. Participation in activity-based video games (exergames) can contribute to estimates of screen time, as current practices of measuring it do not consider the growing evidence that playing exergames can provide light to moderate levels of physical activity. This study aimed to determine what proportion of time spent playing video games was actually spent playing exergames. Methods. Data were collected via a cross-sectional telephone survey in South Australia. Participants aged 18 years and above (n = 2026) were asked about their video game habits, as well as demographic and socioeconomic factors. In cases where children were in the household, the video game habits of a randomly selected child were also questioned. Results. Overall, 31.3% of adults and 79.9% of children spend at least some time playing video games. Of these, 24.1% of adults and 42.1% of children play exergames, with these types of games accounting for a third of all time that adults spend playing video games and nearly 20% of children's video game time. Conclusions. A substantial proportion of time that would usually be classified as "sedentary" may actually be spent participating in light to moderate physical activity.
    Journal of obesity 06/2014; 2014. DOI:10.1155/2014/287013
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    • "Whilst knowledge and awareness of health risks associated with a behaviour are not sufficient to change behaviour alone, they are an important perquisite needed for change (Schwarzer, 2008). Given the evidence of health risks associated with long periods of sitting and its endemic occurrence in everyday activities it is important to identify those population groups who are most unaware of its health risks (Owen et al., 2008; Patel et al., 2010; Pavey et al., 2012; Thorp et al., 2010; van der Ploeg et al., 2012). This is highlighted by qualitative research in office workers that identified that increasing awareness of the health risks associated with sitting may be an important driver for changing sitting behaviours (Gilson et al., 2011). "
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    ABSTRACT: Objective. Prolonged sitting is an emerging risk factor for poor health yet few studies have examined awareness risks associated with sitting behaviours. This study identifies the population subgroups with the highest levels of unawareness regarding the cardiovascular disease (CVD) risks associated with sitting behaviours. Method. Adults (n = 1256) living in Queensland, Australia completed a telephone-based survey in 2011, analysis conducted in 2013. The survey assessed participant's socio-demographic characteristics, physical activity, sitting behaviours and awareness of CVD risks associated with three sitting behaviours: 1) sitting for prolonged periods, 2), sitting for prolonged periods whilst also engaging in regular physical activity, and 3) breaking up periods of prolonged sitting with short activity breaks. Population sub-groups with the highest levels of unawareness were identified based on socio-demographic and behavioural characteristics using signal detection analysis. Results. Unawareness ranged from 23.3% to 67.0%. Age was the most important variable in differentiating awareness levels; younger adults had higher levels of unawareness. Body mass index, physical activity, TV viewing, employment status and time spent at work also identified population sub-groups. Conclusion. Unawareness of CVD risk for prolonged sitting was moderately high overall. Younger adults had high levels of unawareness on all of the outcomes examined.
    Preventive Medicine 05/2014; 65. DOI:10.1016/j.ypmed.2014.05.009 · 2.93 Impact Factor
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    • "There is increasing evidence that time spent in sedentary behaviors (sitting or reclining with low energy expenditure),(Owen, 2012) is associated with poor health outcomes, including obesity, type 2 diabetes, cardiovascular disease and premature mortality (Chau et al., 2013, Thorp et al., 2011, Williams et al., 2008, van der Ploeg et al., 2012, Ford and Caspersen, 2012, Pavey et al., 2012). Over the past 20 years, time spent in sedentary behavior has increased, largely as a result of screen based activities such as watching television and using computers, sedentary modes of transport and sedentary occupations (Chau et al., 2012, Shields and Tremblay, 2008, Church et al., 2011). "
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    ABSTRACT: To examine changes in sitting time (ST) in women over nine years and to identify associations between life events and these changes. Young (born 1973-78, n=5215) and mid-aged (born 1946-51, n=6973) women reported life events and ST in four surveys of the Australian Longitudinal Study on Women's Health between 2000 and 2010. Associations between life events and changes in ST between surveys (decreasers ≥2hrs/day less, increasers ≥2hrs/day more) were estimated using generalized estimating equations. Against a background of complex changes there was an overall decrease in ST in young women (median change -0.48hrs/day, interquartile range [IQR]=-2.54, 1.50) and an increase in ST in mid-aged women (median change 0.43hrs/day; IQR=-1.29, 2.0) over nine years. In young women, returning to study and job loss were associated with increased ST, while having a baby, beginning work and decreased income were associated with decreased ST. In mid-aged women, changes at work were associated with increased ST, while retiring and decreased income were associated with decreased ST. ST changed over nine years in young and mid-aged Australian women. The life events they experienced, particularly events related to work and family, were associated with these changes.
    Preventive Medicine 03/2014; 64. DOI:10.1016/j.ypmed.2014.03.017 · 2.93 Impact Factor
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