Using data from the Prospective Urban Rural Epidemiology (PURE) project, a recent analysis found that spending more than 8 hours a day sitting was linked to an elevated risk of a composite of all-cause death and cardiovascular disease (CVD) events.
More time spent sitting during the day was linked to an increased risk of early death and CVD events, such as cardiovascular death, myocardial infarction (MI), stroke, or heart failure, in this study that followed over 100,000 persons from 21 countries for 8 to 12 years.
Nearly 9% of all deaths were attributed to prolonged sitting and inactivity, which was particularly dangerous.
“This is close to the contribution of smoking (10.6% in our study),” Scott Lear, PhD, Simon Fraser University. Importantly, the increased risks of prolonged sitting were offset by increased physical activity, he said.
The highlight that the finding persisted across the study’s economically diversified settings and was significantly more obvious in lower- and lower-middle-income nations. The authors draw the conclusion that reducing inactive time and boosting physical activity might be an essential strategy for alleviating the global burden of premature mortality and CVD.
JAMA Cardiology published the study online on June 15.
The results are based on information from the PURE cohort, which included 105,677 persons between the ages of 35 and 70 (mean age, 50 years; 59 percent women). A median of 11 years of follow-up resulted in 5696 major CVD events and 6233 deaths.
According to multivariable adjusted models, people who sat for 8 or more hours per day had a 20% higher risk of dying from any cause than people who sat for less than 4 hours per day. A 12 percent higher risk of death and a 13 percent higher risk of severe CVD were found when people sat for 6 to 8 hours a day. Although the link held true for high-, middle-, and low-income countries, it was more pronounced in the latter two groups.
In the study, those who were the least active and sat for more than eight hours a day had the highest risk (up to 50 percent greater). The danger was only 17 percent in individuals who were most inactive but sat the most. The least amount of sitting has the lowest risk.
“We can only speculate why, but it may be due to socioeconomic factors, such that sitting in high-income countries is associated more with higher-paid jobs and higher socioeconomic status,” Lear said. “If you must sit, getting in more exercise at other times during the day can help offset the risks, he noted. It’s important for clinicians to realize the scope of the problem and how substantially sitting and physical inactivity contribute to disease,” Lear told.
Lear advises healthcare professionals to concentrate on the low-cost interventions that increase physical exercise and limit sitting time. He argued that clinicians should take these findings to heart and make sure they are adhering to the activity recommendations in order to maintain their health.
It’s generally difficult to draw conclusions about causes from observational data, but this study of a sizable and diverse group was well-done, according to Harlan Krumholz, MD. According to Krumholz, the link between sedentary behaviour and unfavourable outcomes seems reasonable, and increasing physical activity is the answer because it has few drawbacks and many benefits.
“As our society increasingly drifts toward more screen time and less physical activity, we need to consider what effects that might have on our long-term health and function,” he said. “Humans seem built to move ― and to suffer if we do not. This article certainly supports my bias toward encouraging people to be active and stay active as a way to promote health and lifelong function,” Krumholz added.
Parvathy Sukumaran 
