Can we walk away from cardiovascular disease risk or do we have to ‘huff and puff’? A compositional accelerometer data analysis among adults and older adults in the Copenhagen City Heart Study
Abstract Background: To decrease the risk of cardiovascular disease (CVD), it is unclear whether it is enough to walk more, or if high intensity physical activity (HIPA) is needed. It is also unclear if this differs between adults and older adults. We investigated how sedentary behaviour, walking, and HIPA, were associated with systolic blood pressure (SBP), waist circumference (WC) and low-density lipoprotein cholesterol (LDL-C) among adults and older adults in a general population sample using compositional data analysis. Specifically, the measure of association was quantified by reallocating time between sedentary behaviour and 1) walking, and 2) HIPA. Methods: Cross-sectional data from the fifth examination of the Copenhagen City Heart Study was used. We estimated daily time spent in physical behaviours from accelerometer data worn 24 h/day for 7 days (i.e., right frontal thigh and iliac crest; median wear time: 6 days, 23.8 h/day) using the software Acti4. SBP, WC and LDL-C were measured during a physical examination. Eligible participants had to have ≥5 days with ≥16 h of accelerometer recordings per day, and not use antihypertensives, diuretics or cholesterol lowering medicine. The 24-hour physical behaviour composition consisted of sedentary behaviour, standing, moving, walking, HIPA (i.e., sum of climbing stairs, running, cycling and rowing), and time in bed. We used fitted values from linear regression models to predict the difference in outcome given the investigated time reallocations. Results: Among the 1053 eligible participants we found an interaction between the physical behaviour composition and age. Age-stratified (i.e., </≥65 years; 773 adults, 280 older adults) analyses showed that less sedentary behaviour and more walking compared to the group-specific mean composition was marginally associated with lower SBP among older adults, but not among adults. Less sedentary behaviour and more HIPA was among both adults and older adults marginally associated with a lower SBP, associated with a smaller WC among adults (marginally among older adults) and associated with a lower LDL-C in both age groups. Conclusions: Less sedentary behaviour and more walking seems to be associated with lower risk of CVD among older adults, while HIPA types are associated with lower risk among adults.