Sedentary Time Linked to Increased Mortality Risk in Frail Adults

Sedentary time is associated with increased mortality risk in middle-aged and older individuals who are frail and inactive, but not in individuals who are nonfrail and inactive, according to the results of a recent study.

In their study, the researchers examined data from 3141 community-dwelling adults aged 50-years or older who participated in the 2003/04 and 2005/06 cohorts of the US National Health and Nutrition Examination Survey. The researchers used uniaxial accelerometers to measure duration of sedentary behavior and a 46-item index to measure individuals’ frailty.

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Overall, in individuals with low levels of frailty, sedentary time was not associated with mortality, regardless of physical activity levels. Among individuals who were frail, sedentary time was associated with higher mortality risk in those who were physically inactive.

“The effect of sedentary behaviors on mortality varied by level of frailty. Adults with the highest frailty level experienced the greatest adverse impact. Low frailty levels (frailty index score ≤ 0.1) seemed to eliminate the increased risk of mortality associated with prolonged sitting, even among people who did not meet recommended physical activity guidelines,” the researchers concluded.

—Michael Potts


Theou O, Blodgett JM, Godin J, Rockwood K. Association between sedentary time and mortality across levels of frailty [published online August 21, 2017]. doi: 10.1503/cmaj.161034.