Descriptive epidemiology of physical activity energy expenditure in UK adults. The Fenland Study

Abstract

Background: Physical activity (PA) plays a role in the prevention of a range of diseases including obesity and cardiometabolic disorders. Large population-based descriptive studies of PA, incorporating precise measurement, are needed to understand the relative burden of insufficient PA levels and to inform the tailoring of interventions. Combined heart and movement sensing enables the study of physical activity energy expenditure (PAEE) and intensity distribution. We aimed to describe the sociodemographic correlates of PAEE and moderate-to-vigorous physical activity (MVPA) in UK adults. Methods: The Fenland study is a population-based cohort study of 12,435 adults aged 29 to 64 years-old in Cambridgeshire, UK. Following individual calibration (treadmill), participants wore a combined heart rate and movement sensor continuously for 6 days in free-living, from which we derived PAEE (kJ·day-1·kg-1) and time in MVPA (>3 & >4 METs) in bouts greater than 1 minute and 10 minutes. Socio-demographic information was self-reported. Stratum-specific summary statistics and multivariable analyses were performed. Results: Women accumulated a mean(sd) 50(20) kJ·day-1·kg-1 of PAEE, and 83(67) and 33(39) minutes·day-1 of 1-min bouted and 10-min bouted MVPA respectively. By contrast, men recorded 59(23) kJ·day-1·kg-1, 124(84) and 60(58) minutes·day-1. Age and BMI were also important correlates of PA. Association with age was inverse in both sexes, more strongly so for PAEE than MVPA. Obese individuals accumulated less PA than their normal-weight counterparts whether considering PAEE or allometrically-scaled PAEE (-10 kJ·day-1·kg-1 vs kJ·day-1·kg-2/3 in men). Higher income and manual work were associated with higher PA; manual workers recorded 13-16 kJ·kg-1·day-1 more PAEE than sedentary counterparts. Overall, 86% of women and 96% of men accumulated 21.4 minutes·day-1 of MVPA (>3 METs) on average (150 minutes per week). These values were 49% and 74% if only considering bouts >10 min (15% and 31% for >4 METs). Conclusions: PA varied by age, sex and BMI, and was higher in manual workers and those with higher incomes. Light physical activity was the main driver of PAEE; a component of PA that is currently not quantified as a target in UK guidelines.

Cross-platform genetic discovery of small molecule products of metabolism and application to clinical outcomes

“…We performed genome-wide meta-analyses of the levels of 174 metabolites from 7 biochemical categories (amino acids, biogenic amines, acylcarnitines, phosphatidylcholines, lysophosphatidylcholines, sphingomyelins, and sum of hexoses) captured by the Biocrates p180 kit measured using mass spectrometry (MS). As described in more detail below, a total of 174 metabolites were successfully measured in up to 9,363 plasma samples from genotyped participants of the Fenland study 27 .…”

“…A summary of the characteristics of participating cohorts is given in Supplemental Table S1 . The Fenland study is a population-based cohort study of 12,435 participants without diabetes born between 1950 and 1975 27 . Participants were recruited from general practice surgeries in Cambridge, Ely and Wisbech (United Kingdom) and underwent detailed metabolic phenotyping and genome-wide genotyping.…”

Resting heart rate as a biomarker for tracking change in cardiorespiratory fitness of UK adults: The Fenland Study

“…Physical activity was objectively measured over 6 days using a combined HR and movement sensor (Actiheart, CamNtech, Papworth, UK) with individual calibration of the HR-to-physical activity intensity relationship performed using data from the treadmill test as described above (17). Free-living data was pre-processed (26) and modelled using a branched equation framework (27) to estimate intensity time-series, which was then summarised over time as daily physical activity energy expenditure (PAEE) (kJ/kg per day) (17). Intensity was also expressed in standard metabolic equivalents (METs), using the conversion 1 MET = 71 J/min/kg (~3.5 ml O 2 ⋅min -1 ⋅kg -1 ), and summarised as moderate-to-vigorous physical activity for intensity greater than 3.0 METs.…”

“…Intensity was also expressed in standard metabolic equivalents (METs), using the conversion 1 MET = 71 J/min/kg (~3.5 ml O 2 ⋅min -1 ⋅kg -1 ), and summarised as moderate-to-vigorous physical activity for intensity greater than 3.0 METs. In the present analyses, the proportional PAEE accumulated in moderate and vigorous physical activity was used alongside total PAEE to account for both total physical activity and intensity in the same model (17).…”

“…Participants were invited to attend one of three testing facilities (Ely, Wisbech or Cambridge). Recruitment from general practice surgeries began in 2005, collecting data on a total of 12,435 participants (response rate 27%) as previously described (17). For the present analysis, data from 10,865 individuals was included after excluding participants with key missing variables such as RHR, VO 2 max, physical activity and body composition, as well as participants prescribed beta-blockers (n=315).…”