Time spent sitting related to total mortality

January 01, 0001

Time spent sitting related to total mortality

The obesity epidemic is attributed in part to reduced physical activity. Evidence supports that reducing time spent sitting, regardless of activity, may improve the metabolic consequences of obesity. Analyses were conducted in a large prospective study of US adults enrolled by the American Cancer Society to examine leisure time spent sitting and physical activity in relation to mortality. Time spent sitting and physical activity were queried by questionnaire on 53,440 men and 69,776 women who were disease free at enrolment. The researchers identified 11,307 deaths in men and 7,923 deaths in women during the 14-year follow-up.

After adjustment for smoking, body mass index, and other factors, time spent sitting (6 or more vs less than 3 hours/day) was associated with mortality in both women (relative risk = 1.34) and men (relative risk = 1.17). Relative risks for sitting (6 or more hours/day) and physical activity (less than 24.5 metabolic equivalent (MET)-hours/week) combined were 1.94 for women and 1.48 for men, compared with those with the least time sitting and most activity. Associations were strongest for cardiovascular disease mortality. The time spent sitting was independently associated with total mortality, regardless of physical activity level.

The researchers concluded: "Public health messages should include both being physically active and reducing time spent sitting."

This was by questionnaire and has potential confounders.

For the full abstract, click here.

American Journal of Epidemiology 172(4):419-429 published online 22 July 2010
© 2010 Johns Hopkins Bloomberg School of Public Health
Leisure Time Spent Sitting in Relation to Total Mortality in a Prospective Cohort of US Adults. Alpa V. Patel, Leslie Bernstein, Anusila Deka et al. Correspondence to Alpa Patel: alpa.patel@cancer.org

Category: A. General/Unspecified. Keywords: mortality, motor activity, sedentary lifestyle, prospective cohort study, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 17 September 2010

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