Objectively measured physical activity, sedentary behaviour and all-cause mortality in older men: does volume of activity matter more than pattern of accumulation?

Abstract

Objectives To understand how device-measured sedentary behaviour and physical activity are related to all-cause mortality in older men, an age group with high levels of inactivity and sedentary behaviour. Methods Prospective population-based cohort study of men recruited from 24 UK General Practices in 1978 -1980 . In 2010 surviving men were invited to a follow-up, 1655 (aged 71-92 years) agreed. Nurses measured height and weight, men completed health and demographic questionnaires and wore an ActiGraph GT3x accelerometer. All-cause mortality was collected through National Health Service central registers up to 1 June 2016. results After median 5.0 years' follow-up, 194 deaths occurred in 1181 men without pre-existing cardiovascular disease. For each additional 30 min in sedentary behaviour, or light physical activity (LIPA), or 10 min in moderate to vigorous physical activity (MVPA), HRs for mortality were 1.17 (95% CI 1.10 to 1.25), 0.83 (95% CI 0.77 to 0.90) and 0.90 (95% CI 0.84 to 0.96), respectively. Adjustments for confounders did not meaningfully change estimates. Only LIPA remained significant on mutual adjustment for all intensities. The HR for accumulating 150 min MVPA/week in sporadic minutes (achieved by 66% of men) was 0.59 (95% CI 0.43 to 0.81) and 0.58 (95% CI 0.33 to 1.00) for accumulating 150 min MVPA/week in bouts lasting ≥10 min (achieved by 16% of men). Sedentary breaks were not associated with mortality. Conclusions In older men, all activities (of light intensity upwards) were beneficial and accumulation of activity in bouts ≥10 min did not appear important beyond total volume of activity. Findings can inform physical activity guidelines for older adults.Nearly all epidemiological evidence used to estimate the shape of the dose-response curve between physical activity (PA) and mortality is based on self-reported PA.1 Moderately active compared with inactive adults have 20%-30% reductions in all-cause mortality, with greater reductions in older (>65 years) than middle-aged adults.2 PA is a key determinant of longevity globally.3 Current activity guidelines suggest accumulating ≥150 min moderate to vigorous PA (MVPA) per week in bouts lasting ≥10 min.4 5 The 10 min bout requirement was based on trial data for cardiometabolic risk factors only, not clinical end points. 5 In order to test whether the accumulation of MVPA in ≥10 min bouts affects risk of mortality, prospective cohort studies with device-measured physical activity (which can provide minute by minute data for calculation of bouts) and mortality data are required, but few studies have such data. Such data can also inform whether accruing sedentary time in prolonged bouts is associated with adverse effects on mortality, as this has been identified as an important research gap. Many studies report that higher levels of self-reported sedentary time are associated with mortality, [6][7][8][9] although self-reported sedentary behaviours may suffer from measurement error or recall bias.10-14 Experimental studies suggest benefits...

Accumulation of Moderate‐to‐Vigorous Physical Activity and All‐Cause Mortality

“…Their results indicate that total MVPA with no bout requirement, MVPA in 5‐minute bouts, and MVPA in 10‐minute bouts resulted in similar risk reductions for all‐cause mortality. These data are similar to a recent report on health outcomes in older men that found total activity, including light intensity and activity expressed in bouts, was inversely related to all‐cause mortality …”

“…that found total activity, including light intensity and activity expressed in bouts, was inversely related to all-cause mortality. 7 In the research reported by Saint-Maurice and colleagues, the adjusted hazard ratios for all-cause mortality for increasing quartiles of total MVPA were 0.43, 0.24, and 0.27 for quartiles 2, 3 and 4, respectively (quartile 1 as reference). 6 In prior systematic reviews or meta-analysis using self-report PA data, the hazard or risk ratios for all-cause mortality when comparing the more or most active with the least active have been closer to 0.60 to 0.65.…”

Device‐measured light‐intensity physical activity and mortality: A meta‐analysis

“…Of these, 1010 articles were excluded after title and abstract screening and 23 full-text articles were assessed for potential eligibility. 10,11,[19][20][21][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] Of these 23 articles, six studies met the criteria. 10,11,[19][20][21]33 From the remaining 17 studies contacted via email, five of them provided the requested results.…”

“…10,11,[19][20][21][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] Of these 23 articles, six studies met the criteria. 10,11,[19][20][21]33 From the remaining 17 studies contacted via email, five of them provided the requested results. [29][30][31][32]34 Eight studies did not provide cutoff point of LPA because data re-analysis was not available, [36][37][38][40][41][42]44,45 one study included participants with chronic kidney disease, 35 and the other three studies did not adjust for MVPA.…”

Seven days in medicine: 14-20 February 2018

“…Clocking up just a few minutes at a time of any level of physical activity, rather than the recommended 10 minute bouts, is linked to a lower risk of death in older men as long as they reach the target of 150 minutes a week, suggested a study published in the British Journal of Sports Medicine 3. Each additional 30 minutes a day of light activity, such as gentle gardening or taking the dog for a walk, was associated with a 17% lower risk of death.…”