Objective Measures of Activity Level and Mortality in Older Men

<jats:sec><jats:title>Objectives</jats:title><jats:p>To examine associations between objective measures of activity level and mortality risk in older men.</jats:p></jats:sec><jats:sec><jats:title>Design</jats:title><jats:p>Prospective cohort study.</jats:p></jats:sec><jats:sec><jats:title>Setting</jats:title><jats:p>Six U.S. sites.</jats:p></jats:sec><jats:sec><jats:title>Participants</jats:title><jats:p>Men aged 71 and older followed an average of 4.5 years (N = 2,918).</jats:p></jats:sec><jats:sec><jats:title>Measurements</jats:title><jats:p>Time awake spent in sedentary behavior (metabolic equivalent (<jats:styled-content style="fixed-case">MET</jats:styled-content>) level ≤1.50), light activity (<jats:styled-content style="fixed-case">MET</jats:styled-content> level 1.51–2.99), and at least moderate activity (<jats:styled-content style="fixed-case">MET</jats:styled-content> level ≥3.00) measured using an activity monitor worn for 5 days or longer and expressed as quartiles. Deaths were confirmed with death certificates; cause of death was adjudicated by review of certificates and records.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>During follow‐up, 409 (14%) men died. After multivariable adjustment, comparing Q4 with Q1, more time spent in sedentary behavior (Q4 vs Q1, hazard ratio (<jats:styled-content style="fixed-case">HR</jats:styled-content>) = 1.51, 95% confidence interval (<jats:styled-content style="fixed-case">CI</jats:styled-content>) = 1.10–2.08), less time spent in light activity (Q1 vs Q4, <jats:styled-content style="fixed-case">HR</jats:styled-content> = 1.54, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> = 1.06–2.24), and less time spent in at least moderate activity (Q1 vs Q4, <jats:styled-content style="fixed-case">HR</jats:styled-content> = 1.56, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> = 1.09–2.25) were similarly associated with greater mortality risk primarily due to higher risks of cardiovascular and noncardiovascular, noncancer death. The association between time spent in sedentary behavior and mortality varied according to time spent at higher activity level. More time spent in sedentary behavior was associated with greater risk of death in men spending 1.2 (median) h/d or more in at least moderate activity (Q4 vs Q1, <jats:styled-content style="fixed-case">HR</jats:styled-content> = 2.09, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> = 1.26–3.49) but not in those spending less time (Q4 vs Q1, <jats:styled-content style="fixed-case">HR</jats:styled-content> = 1.02, 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> = 0.62–1.66) (<jats:italic>P</jats:italic> = .005 for interaction).</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>In older men exceeding current guidelines on physical activity, more time spent in sedentary behavior is associated with greater mortality risk.</jats:p></jats:sec>