August 17, 2017 (Toronto, Ont.)—Workers who stand on the job most of the time are at greater risk of heart disease than workers who predominantly sit.
According to a study just published in the American Journal of Epidemiology (doi 10.1093/aje/kwx298), even after taking into account a wide range of personal, health and work factors, people who primarily stand on the job are twice as likely as people who primarily sit on the job to have a heart attack or congestive heart failure.
“Workplaces have been hearing a lot lately about the health effects of prolonged sitting on the job,” says Institute for Work & Health (IWH) Senior Scientist Dr. Peter Smith, who led a team of researchers from IWH and the Institute for Clinical Evaluative Sciences (ICES) to conduct this study. “Our results suggest that workplaces also need to pay attention to the health effects of prolonged standing, and target their prevention programs accordingly.”
The study followed 7,300 workers aged 35-74 from Ontario, Canada (who were initially free of heart disease) for 12 years. These workers were respondents to the 2003 Canadian Community Health Survey (CCHS), which collected information on personal factors, health conditions, health behaviours and work conditions. It also collected job title information, which was used to estimate if a job primarily involved sitting, standing/walking, a combination of sitting/standing/walking or other body posture (such as bending or kneeling). Among the group included in the study, nine per cent were estimated to predominantly stand at work, and 37 per cent were estimated to predominantly sit. The researchers then linked the CCHS information to administrative health records housed at ICES to identify people who had a new case of heart disease over the next 12 years (2003-2015).
During this period, 3.4 per cent of the study group developed heart disease—more men (4.6 per cent) than women (2.1 per cent). Without taking any other factors into account (the unadjusted risk), the risk of heart disease was higher among people whose jobs required mostly standing (6.6 per cent) than among people whose jobs involved mostly sitting (2.8 per cent).
Even after adjusting for a wide range of factors— personal (e.g. age, gender, education levels, ethnicity, immigrant status, marital status), health conditions (e.g. diabetes, arthritis, hypertension, mood and anxiety disorders), health behaviour (e.g. smoking, drinking, body mass index, exercise) and work (e.g. physical demands, shift schedule) — the risk of heart disease was still twice as high among people who primarily stood on the job compared to those who primarily sat. In fact, the unadjusted risk of heart disease among people who stood on the job (6.6 per cent, as mentioned above) was even slightly higher than among daily smokers (5.8 per cent).
“A combination of sitting, standing and moving on the job is likely to have the greatest benefits for heart health,” says Smith. “Workplaces need to apply this message not just to workers who predominantly sit, but also — in fact, especially — to workers who predominantly stand.”
That said, workplaces need to look beyond physical job activity to truly protect the cardiovascular health of workers, Smith adds. While jobs that involved a combination of sitting, standing and walking were shown in this study to be associated with a decreased risk of heart disease among men, these jobs didn’t result in a decreased risk among women. Smith suspects this is due to the fact that nurses and teachers accounted for most of the jobs held by women in the “sitting, standing and walking” category, jobs known to be stressful in different ways.
“Prevention programs that focus solely on physical job activity, while ignoring other conditions such as the psychosocial work environment, are unlikely to lead to meaningful changes in cardiovascular risk,” Smith says.
About the Institute for Clinical Evaluative Sciences (ICES)
ICES is an independent, non-profit organization based in Toronto, Canada, that uses population-based health information to produce knowledge on a broad range of health-care issues. Its unbiased evidence provides measures of health system performance, a clearer understanding of the shifting health-care needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners and practitioners to make decisions about care delivery and to develop policy: www.ices.on.ca