We take a close look at a recent research paper and explore how its findings can inform OSH practice.
Journal of the American Heart Association
There is a need to explore common activity patterns undertaken by workers and the association between these activity profiles and cardiovascular disease (CVD). This study set out to explore the number and type of distinct profiles of activity patterns among workers and the association between these profiles, and predict 10-year risk for a first atherosclerotic CVD event.
Methods and findings
Distinct activity patterns from a cross-section of workers’ accelerometer data were sampled from Canadian Health Measures Survey participants (five cycles, 2007-17) and identified using hierarchical cluster analysis techniques. Six distinct activity profiles were identified from 8909 workers. Compared with the ‘lowest activity’ profile, individuals in the ‘highest activity’ and ‘moderate evening activity’ profiles were at 42% lower risk and 33% lower risk of predicted 10-year atherosclerotic CVD risk of >10%, respectively. ‘Moderate activity’ and ‘fluctuations of moderate activity’ profiles were also associated with lower risk estimates, whereas the ‘high daytime activity’ profile was not statistically different to the reference profile.
The six activity profiles of workers were:
- Steady movers (3219 workers). This group has moderate activity levels throughout the day, followed by light activity during the evening. They report low levels of physical activity for recreation. Compared with sedentaries, they have a 14% lower risk of heart disease over 10 years.
- The sedentaries (2808 workers). This group engages in low or light activity during at‑work and off-work hours. They report low levels of recreational physical activity.
- Dynamic movers (1194 workers). This group alternates between light activity and moderate activity throughout the day. They are the second most active group for recreational activities. Compared with sedentaries, the group has a 27% lower risk of heart disease over 10 years.
- Physical workers (713 workers). This group engages in vigorous physical activity during most daytime hours. This group’s risk of heart disease does not differ from sedentaries in a statistically significant way.
- The night shifters (225 workers). This group stays moderately active from midday through to midnight. Its risk of heart disease is 33% lower than that of sedentaries.
- Exercisers (750 workers). This group spends parts of the work day doing light or moderate activity, but also engages in vigorous physical activity at the start of the day, around noon, and again in the late afternoon and early evening. This group has the highest level of recreational physical activity. It has a 42% lower risk of heart disease compared with sedentaries.
Workers accumulating physical activity throughout the day and during recreational hours were found to have optimal CVD risk profiles. Workers accumulating physical activity only during daytime work hours were not associated with reduced CVD risk. Findings can inform alternative strategies to conferring the cardiovascular benefits of physical activity among workers. Large prospective studies are needed to confirm these findings.
‘We typically think a sedentary lifestyle is a risk factor for heart disease and that we should be more active throughout the day to lower our risk. Our research suggests the health effects of activity are different depending on the context in which it is accumulated. Workers who are very active or moderately active mostly during their daytime work hours might not be any different to sedentary people in terms of their future heart disease risk. This might be because work-related activity is either too low to improve fitness, or too physically strenuous and with little opportunity to rest. Strategies promoting physical activity only during work hours may be less effective than those promoting physical activity outside work hours.’ Aviroop Biswas, lead author
Implications for practice – IOSH’s take
When we think of sedentary work, we immediately think of the health implications around tasks and job roles where there is a lack of movement, such as sitting, reclining or standing. This research not only brings to light new types of sedentary work, but also emphasises the health impact these types of sedentary work can have. The paper gives OSH professionals an opportunity to consider tasks that could have health implications for workers which might not have been considered. One example of this is workers who are conducting physically strenuous tasks with little rest – this could be manual handling tasks – and looking at this not only from an MSD perspective but also having the knowledge to appreciate these tasks could have cardiovascular implications if they are not managed effectively.