The high cost of a sedentary lifestyle just became a bit more evident ― a new global study shows that inactivity drives up to 8% of noncommunicable diseases and mortality.
Physical inactivity, defined as engaging in less than 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity per week, is estimated to have caused 7.2% (95% CI, 5.4 – 9.0) of all-cause deaths and 7.6% (95% CI, 6.1 – 9.3) of cardiovascular disease (CVD) deaths, according to investigators led by Peter T. Katzmarzyk, PhD, associate executive director for population and public health sciences, Pennington Biomedical Research Center, Baton Rouge, Louisiana.
The results, based on population data for 15 health outcomes across 168 countries, were published online March 29 in the British Journal of Sports Medicine.
The prevalence-based population-attributable risks (PARs) caused by a sedentary lifestyle range from 1.6% (95% CI, 1.0 – 2.4) for hypertension to 8.1% (95% CI, 2.6 – 14.9) for dementia, report Katzmarzyk and colleagues.
PARs are more than twice as high in high-income regions, such as the West and Asia-Pacific, as in low-income areas, such as Oceania, East/Southeast Asia, and sub-Saharan Africa. In the populous middle-income regions of Latin America and the Caribbean, 69% of total deaths and 74% of CVD deaths are associated with physical inactivity.
“The results support the notion that physical activity is having a broad impact on population health,” Katzmarzyk told Medscape Medical News. “Both policy-level changes to promote physical activity and clinical and work-site interventions are warranted. It is important to intervene at all levels to help increase physical activity in all contexts.”
For their study, Katzmarzyk and associates determined the global prevalence of insufficient physical activity from data collected in 2016 for adults from 168 countries.
They then examined the effect of physical activity in large recent meta-analyses and pooled-data studies for 15 adverse health outcomes: all-cause mortality, CVD mortality, dementia, depression, coronary artery disease, stroke, type 2 diabetes, and hypertension, as well as bladder, breast, colon, endometrial, esophageal, gastric, and renal cancer.
The calculations were aggregated for each country with respect to World Health Organization region and World Bank country income groups.
Although he believes the findings are generalizable to different populations around the world, Katzmarzyk concedes that most research on this topic has been done in high-income countries. “But there’s no evidence these results would not be applicable to other populations,” he said. “Similar to those of smoking, the adverse consequences of inactivity appear to be universal in humans.” However, more studies are needed in different populations to confirm the results.
Captain Richard P. Troiano, PhD, a program director in the National Cancer Institute’s Division of Cancer Control and Population Sciences, believes the estimates are applicable to the United States, inasmuch as most of the population risk estimates are from high-income countries. “Other factors, such as competing risks, may complicate the application to lower-income countries, but the application of standardized risk estimates is certainly a reasonable approach,” said Troiano, who did not participate in the current study but was involved in two source documents referred to in the study.
The current findings support earlier studies that demonstrate that physical inactivity is associated with a significant public health burden. “However, the evidence now shows associations with 10 or more chronic diseases,” Katzmarzyk said. His group believes collaboration on an international scale is necessary to mobilize change regarding this global health issue.
Although the connection between inactivity and disease is not new, “[t]his new evidence helps elevate the importance of physical activity,” said Melody Ding, PhD, MPH, an associate professor in the School of Public Health at the University of Sydney, Sidney, Australia. “There are many diseases physical activity prevents, and therefore populations around the world should engage in more physical activity for a myriad of health benefits,” she said.
Ding, who was not involved in the current study, stressed the importance of distinguishing between exercise and physical activity. “Exercise is physical activity done in one’s leisure time for the intention of recreation or fitness. Physical activity includes everything,” she told Medscape Medical News. “What governments should promote around the world is a population update of physical activity, which includes any movement, such as walking to shops, cycling to work, taking stairs at work, working in the yard, and, of course, exercise.”
According to Troiano, removing environmental barriers to physical activity and actively promoting it at multiple levels are required. “Considerable evidence supports the need for changes to transportation systems, land use, and environment design to increase physical activity in urban areas,” he said.
Healthcare professionals are uniquely positioned to highlight the importance of physical activity by asking patients about their energy expenditure and encouraging more. “A recent study of time use found that Americans reported an average of more than 5 hours per day of free time but spent 24 minutes or less in physical activity,” Troiano said. “Physicians and other healthcare providers could emphasize how choosing a little more freedom time for physical activity could substantially improve health and well-being.”
The study was supported in part by the National Institutes of Health’s General Medicine Sciences, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Institute on Aging. The authors, Troiano, and Ding have disclosed no relevant financial relationships.
Br J Sports Med. Published online March 29, 2021. Full text
Diana Swift is a medical journalist based in Toronto. She can be reached at firstname.lastname@example.org.
Follow Medscape on Facebook, Twitter, Instagram, and YouTube.