Joint association of accelerometer-measured physical activity and sedentary time with all-cause mortality: a harmonized meta-analysis in more than 44,000 middle-aged and older individuals 

Ekelund U, Tarp J, Fagerland MW, et al. Joint association between accelerometer-measured physical activity and sedentary time and all-cause mortality: a harmonized meta-analysis in more than 44,000 middle-aged and older individuals British Journal of Sports Medicine 2020; 54 : 1499-1506

Commentary

This study was designed to investigate the joint association of accelerometer-measured physical activity and sedentary time with all-cause mortality.

It was a meta-analysis of nine prospective cohort studies from four countries, involving 44,370 individuals, followed for five years, during which time 3451 deaths were reported. (Mortality rate 7.8%)

The association between moderate to vigorous intensity physical activity (MVPA) and sedentary time combined was analyzed using Cox proportional hazards regression analysis and summarized using a variable effects meta-analysis.

The results showed that the mean duration of sedentary life across the cohort ranged from 8.5 hours/day to 10.5 hours/day and from 8 minutes/day to 35 minutes/day for MVPA.

Compared to the reference group, the risk of death increased with lower levels of MVPA and longer sedentary time; among the highest third of MVPA, the risk of death was intermediate (16%; 95% CI 0.87% to 1.54%) highest (40%; 95% CI 0.87% to 1.54%) ) were not statistically different from those indicated.

These results suggest that the longer the sedentary time, as measured by accelerometers, the higher the mortality rate for inactive individuals; MVPA of about 30-40 minutes per day weakens the association between sedentary time and mortality risk.