It might be time to get up and do a few stretches — over 7% of all-cause and cardiovascular disease (CVD) deaths and up to 8% of non-communicable diseases around the globe can be attributed to physical inactivity, researchers found.
At this point, the link between physical inactivity and risk of premature mortality is a tale as old as time. For example, one study from 2012 estimated that physical inactivity caused between 6% and 10% of worldwide premature mortality, coronary heart disease, type 2 diabetes, breast cancer, and colon cancer. However, despite the widespread knowledge that physical activity leads to better health outcomes, 27.5% of adults fall short of current public health guidelines for physical activity, Peter T. Katzmarzyk, PhD, of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, and colleagues explained in the British Journal of Sports Medicine.
They set out to determine the current global burden of non-communicable diseases associated with physical inactivity and examine variations by geographical region and level of national income.
“The global health burden associated with physical inactivity is substantial,” Katzmarzyk and colleagues wrote. “These data are crucial to inform governments and policy-makers, particularly in populous middle-income countries. While the relative non-communicable disease burden is greatest in high-income countries, middle-income countries have the greatest number of people affected by physical inactivity…Our results provide evidence that the public health burden associated with physical inactivity is truly a global issue that will require international collaboration to mobilize change and achieve these public health goals.”
For their analysis, the study authors determined the major health outcomes most closely associated with physical inactivity, relying on evidence from the U.S. 2018 Physical Activity Guidelines Advisory Committee — the Committee reported strong evidence that physical inactivity is linked to risk of “all-cause mortality, [CVD] mortality, and incidence of coronary heart disease, stroke, hypertension, type 2 diabetes, several cancers (bladder, breast, colon, endometrial, esophageal, gastric, renal), dementia, and depression,” they explained. They did not include outcomes that the Committee deemed to have moderate, weak, or insufficient evidence for associations with physical activity, they added.
The study authors calculated a “semiadjusted population attributable risk” (PARsemi) for each outcome, which was calculated using the prevalence of physical activity in the source population and the multivariable-adjusted relative risk (RR) for the outcome in a physically inactive person. The prevalence of insufficient physical activity was obtained from a recent publication of data collected in 2016 for adults from 168 countries. Insufficient activity was defined as falling short of current guidelines — at least 150 min of moderate-intensity or 75 min of vigorous-intensity physical activity per week, or equivalent.
PARsemi was computed for each outcome by country, World Bank Income Classification, and geographical region.
“We assumed normal distributions for physical inactivity prevalence and the log of the RRs,” they wrote. “Given that single RR estimates were used to compute all PARs for a given outcome, differences in PARs across countries or regions reflect the differences in physical inactivity prevalence. To estimate the number of global deaths attributable to physical inactivity, we applied the PARs for all-cause mortality and cardiovascular disease mortality to the number of deaths (ages ≥15 years) from low-income, middle-income and high-income countries in 2016.”
The study authors found that, worldwide, “7.2% and 7.6% of all-cause and cardiovascular disease deaths, respectively, are attributable to physical inactivity. Further, the proportions of non-communicable diseases attributable to physical inactivity range from 1.6% for hypertension to 8.1% for dementia. There was an increasing gradient across income groups; PARs were more than double in high-income compared with low-income countries. However, 69% of total deaths and 74% of cardiovascular disease deaths associated with physical inactivity are occurring in middle-income countries, given their population size. Regional differences were also observed, with the PARs occurring in Latin America/Caribbean and high-income Western and Asia-Pacific countries, and the lowest burden occurring in Oceania and East/Southeast Asia.”
To put their findings into context, Katzmarzyk and colleagues noted that “the 7% global PAR for all-cause mortality associated with physical inactivity compares with an estimated global PAR of 8.7% for global tobacco use, 1.2% for global sugar-sweetened beverage consumption, 10% in women and 11% in men for obesity in Europe, and between 3% and 15% for obesity in the USA.”
While these findings shed light on the overall health burden of physical inactivity around the world, the study authors argued that more definitive results can be derived from future studies that “track actual changes in physical activity over time using device-based measurement methods and resulting changes in non-communicable disease incidence and prevalence…” They added that future analyses should make use of surveillance and outcome data across varying levels of physical activity to better quantify the global health burden, and that data on physical activity across sex and age groups should be incorporated.
Study limitations included use of a theoretical population-based approach to estimate disease burden; an inability to estimate PARs using a dose-response approach; and an inability to account for different exposure-outcome associations at different ages.
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Physical inactivity poses a substantial global health burden, accounting for over 7% of all-cause and cardiovascular disease (CVD) deaths and up to 8% of non-communicable diseases around the globe.
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Note that while relative non-communicable disease burden was greatest in high-income countries, middle-income countries have the greatest number of people affected by physical inactivity.
John McKenna, Associate Editor, BreakingMED™
The study authors had no relevant relationships to disclose.
Cat ID: 192
Topic ID: 86,192,730,6,8,914,13,935,192,48,669,916,918,925
