Back to Journals » Clinical Epidemiology » Volume 10

Replacing sedentary time with physical activity: a 15-year follow-up of mortality in a national cohort

Authors Dohrn IM, Kwak L, Oja P, Sjöström M, Hagströmer M

Received 14 September 2017

Accepted for publication 23 November 2017

Published 25 January 2018 Volume 2018:10 Pages 179—186


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 3

Editor who approved publication: Professor Irene Petersen

Ing-Mari Dohrn,1 Lydia Kwak,2 Pekka Oja,3 Michael Sjöström,4 Maria Hagströmer1,5

1Department of Neurobiology, Care Sciences and Society (NVS), 2Institute of Environmental Medicine (IMM), Karolinska Institutet, Stockholm, Sweden; 3UKK Institute, Tampere, Finland; 4Department of Biosciences and Nutrition (BioNut), Karolinska Institutet, 5Functional Area Occupational Therapy and Physiotherapy, Karolinska University Hospital, Stockholm, Sweden

Background: Sedentary behavior is associated with health risks in adults. The potential benefits of reducing sedentary time may be dependent not only on decrease per se, but also on the type of activity it replaces. Few longitudinal studies have investigated the effects on mortality when replacing objectively assessed sedentary time with another physical activity (PA) behavior.
Objective: To investigate the effects of replacing objectively assessed sedentary time with time in light-intensity PA or moderate-vigorous PA (MVPA) on all-cause mortality, cardiovascular disease (CVD) mortality or cancer mortality in a cohort with 15 years follow-up time.
Methods: In total, 851 women and men from the population-based Sweden Attitude Behaviour and Change study were included. Time spent sedentary, in light-intensity PA and in MVPA were assessed using an Actigraph 7164 accelerometer. Mortality data were obtained from Swedish registers. Cox proportional hazards models estimated hazard ratios (HR) of mortality with 95% confidence intervals (CI) and isotemporal substitution models were used to estimate the effect of replacing sedentary behavior with PA for the same amount of time.
Results: Over a follow-up of 14.2 years (SD 1.9) with 12,117 person-years at risk, 79 deaths occurred, 24 deaths from CVD, 27 from cancer, and 28 from other causes. Replacing 30 minutes/day of sedentary time with light-intensity PA was associated with significant reduction in all-cause mortality risk (HR: 0.89, 95% CI: 0.81-0.98) and CVD mortality risk (HR: 0.76, 95% CI: 0.63-0.92). Replacing 10 minutes of sedentary time with MVPA was associated with reduction in CVD mortality risk (HR: 0.62, 95% CI: 0.42-0.91). No statistically significant reductions were found for cancer mortality.
Conclusion: This statistical modelling study suggests that replacing sedentary time with light-intensity PA could have beneficial effect on both all-cause mortality and CVD mortality. Replacing sedentary time with MVPA could reduce CVD mortality.

Keywords: accelerometry, isotemporal substitution, light intensity, moderate-to-vigorous intensity, prospective, sedentary behavior

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]