However, daily breaks from sitting and leisure-time activity can help mitigate the “serious” risks associated with prolonged occupational sitting, the researchers say.
“As part of modern lifestyles, prolonged occupational sitting is considered normal and has not received due attention, even though its deleterious effect on health outcomes has been demonstrated,” wrote the authors, led by Wayne Gao, PhD, with Taipei Medical University College of Public Health, Taipei City, Taiwan.
“The importance of physical activity and moving around can never be overstated,” Michelle Bloom, MD, director of the cardio-oncology program at NYU Langone Health in New York, who wasn’t involved in the study, told this news organization.
“As a cardiologist, I bring this up at almost every visit with every patient regardless of why they’re seeing me, because I think that patients respond better when their doctor says it than when they just kind of know it in the back of their mind,” said Dr. Bloom, who is also a professor in the Division of Cardiology, NYU Grossman Long Island School of Medicine, New York.
The study was published online in JAMA Network Open.
Prolonged Sitting Hard on the Heart
2020 marked the first time that guidelines on physical activity from the World Health Organization recommended reducing sedentary behaviors owing to their health consequences. Less is known on the specific association of prolonged occupational sitting with health outcomes, especially in the context of low physical activity.
For their study, Dr. Gao and colleagues quantified health risks associated with prolonged sitting on the job and determined whether a certain threshold of physical activity may attenuate this risk.
Participants included 481,688 adults (mean age, 39 years; 53% women) in a health surveillance program in Taiwan. Data on occupational sitting, leisure-time physical activity, lifestyle, and metabolic parameters were collected.
During an average follow up of nearly 13 years, 26,257 participants died; more than half (57%) of the deaths occurred in individuals who mostly sat at work. There were 5371 CVD-related deaths, with 60% occurring in the mostly sitting group.
In multivariate analysis that adjusted for sex, age, education, smoking, drinking, and body mass index, adults who mostly sat at work had a 16% higher risk of dying of any cause (hazard ratio [HR], 1.16; 95% CI, 1.11-1.20) and a 34% increased risk of dying of CVD (HR, 1.34; 95% CI, 1.22-1.46) compared with those who mostly did not sit at work.
Adults who mostly alternated between sitting and not sitting at work were not at increased risk of all-cause mortality compared with individuals who mostly did not at work (HR, 1.01; 95% CI, 0.97-1.05).
Among adults who mostly sat at work and engaged in low (15-29 minutes) or no (< 15 minutes) daily leisure-time activity, increasing activity by 15 and 30 minutes per day, respectively, lowered the risk for mortality to a level similar to that of inactive individuals who mostly do not sit at work.
“Overall, our findings from a large prospective cohort help to strengthen the increasingly accumulating evidence linking a sedentary lifestyle and health risks,” the authors wrote.
“Systemic changes, such as more frequent breaks, standing desks, designated workplace areas for physical activity, and gym membership benefits, can help reduce risk,” they added.