Bidirectional associations of accelerometer-assessed physical activity and sedentary time with physical function among older English adults: the EPIC-Norfolk cohort study

Abstract

To develop healthy ageing interventions, longitudinal associations between objectively assessed physical behaviours and physical function need to be better understood. We assessed associations between accelerometer-assessed total physical activity (PA), moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), sedentary time and prolonged sedentary bout time, and clinically assessed physical function (grip strength, usual walking speed (UWS), chair stand speed) at two time-points in 3188 participants (≥ 60 years) of the EPIC-Norfolk study. Bidirectional associations were assessed using multivariable linear regression. Over an average of 6.1 years, baseline physical behaviours (greater total PA, MVPA and LPA, and less sedentary time) were associated with better subsequent walking and chair stand speed. Better baseline physical function was associated with better follow-up physical behaviours. There were no bidirectional associations between changes in physical behaviours and grip strength. Improvements in UWS were associated with improvements in all physical behaviours. Improvements in chair stand speed were associated with improvements in total PA, MVPA, and sedentary bout time. Improvements in physical behaviours were associated with improvements in UWS (3.1 cm/s/yr per 100 cpm/yr total PA, 3.6 cm/s/yr per hr/day/yr MVPA, 2.5 cm/s/yr per hr/day/yr LPA, - 2.9 cm/s/yr per hour/day/yr sedentary time, and - 1.6 cm/s/yr per hr/day/yr prolonged sedentary bout time). Only improvements in total PA, MVPA and sedentary bout time were associated with improvements in chair stand speed. In conclusion, we found bidirectional associations between changes in some physical behaviours and physical function and between baseline physical behaviours and subsequent physical function, highlighting the importance of considering the full range of physical behaviours to promote healthy ageing.

Supplementary information: The online version contains supplementary material available at 10.1007/s10433-022-00733-y.

Keywords: Older adults; Physical activity; Physical function; Sedentary time.

Fig. 1

The bidirectional associations between physical function and physical behaviours. For all panels, MVPA is in green, LPA is in blue, ST is in red and Prolonged ST bouts is in orange. Beta is indicated by central square, 95% CI is indicated by the line. Baseline measures were taken between 2006 and 2011, and follow-up measures were taken between 2012 and 2016. Change in variables was from baseline to follow-up. In Panels A and B, results are from model 3. For Panel A, Beta is the number of mins/day of follow-up physical behaviours associated with each unit of the baseline physical function measure. For Panel B, Beta is the number of units of follow-up physical function measure associated with an hour/day of baseline physical behaviours. In Panels C and D, results are from model 3. For Panel C, Beta is the number of mins/day/year change in physical behaviour over follow-up associated with each unit/year change in the physical function measure. For Panel D, Beta is the number of units/year of change in physical function associated with an hour/day change in physical behaviour

Fig. 1

The bidirectional associations between physical function and physical behaviours. For all panels, MVPA is in green, LPA is in blue, ST is in red and Prolonged ST bouts is in orange. Beta is indicated by central square, 95% CI is indicated by the line. Baseline measures were taken between 2006 and 2011, and follow-up measures were taken between 2012 and 2016. Change in variables was from baseline to follow-up. In Panels A and B, results are from model 3. For Panel A, Beta is the number of mins/day of follow-up physical behaviours associated with each unit of the baseline physical function measure. For Panel B, Beta is the number of units of follow-up physical function measure associated with an hour/day of baseline physical behaviours. In Panels C and D, results are from model 3. For Panel C, Beta is the number of mins/day/year change in physical behaviour over follow-up associated with each unit/year change in the physical function measure. For Panel D, Beta is the number of units/year of change in physical function associated with an hour/day change in physical behaviour