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Summary: Those who sit six or more hours a day are at significantly increased risk of heart disease and early death.
Source: Simon Fraser University
New research adds weight to the argument that prolonged sitting can be harmful to your health.
An international study that surveyed more than 100,000 people in 21 countries found that people who sat six to eight hours a day had a 12 to 13 percent increased risk of early death and heart disease, while those who sat more when sitting eight hours a day, this increased to a sobering 20 percent.
The study, co-led by Simon Fraser University professor of health sciences Scott Lear, and Wei Li of the Chinese Academy of Medical Sciences in Beijing, is published today in the journal JAMA Cardiology.
Their research followed individuals for an average of 11 years and found that long periods of sitting were associated with an increased risk of early death and cardiovascular disease. While sitting was problematic in all countries, it was particularly so in low- and middle-income countries.
“The overall message here is to minimize sitting time,” says Lear. “If you have to be sedentary, that risk is offset by more exercise at other times of the day.”
Not surprisingly, those who were most sedentary and least active had the highest risk — up to 50 percent — while those who were most sedentary but also most active had a substantially lower risk of around 17 percent had.
“For those who sit more than four hours a day, replacing half an hour of sitting with exercise reduced the risk by two percent,” Lear notes. “With only one in four Canadians meeting the activity guidelines, there’s a real opportunity for people to increase their activity levels and reduce their chances of early death and heart disease.”
The study found a particular association in low-income countries, leading researchers to suggest that sitting in higher-income countries is typically associated with higher socioeconomic status and better-paying jobs.
Physicians should focus on less sitting and more activity because it’s a low-cost intervention that can have tremendous benefits, Lear notes.
But while clinicians need to spread the message to counter sedentary life with activity, individuals need to be more self-aware of their lifestyles and take their health seriously, Lear adds. “Our study found that a combination of sitting and inactivity accounted for 8.8 percent of all deaths, which is close to the contribution of smoking” (10.6 percent in Lear and Li’s study). “It’s a global problem that has a remarkably simple solution. Allowing time to get out of that chair is a good start.”
About this cardiovascular disease research news
Author: press office
Source: Simon Fraser University
Contact: Press Office – Simon Fraser University
Picture: The image is in the public domain
Original research: Closed access.
“Association of sedentary time with mortality and cardiovascular events in high, middle, and low-income countries” by Sidong Li et al. JAMA Cardiology
abstract
Association of sedentary time with mortality and cardiovascular events in high-, middle-, and low-income countries
meaning
Long periods of sitting are associated with an increased risk of cardiovascular disease (CVD) and mortality in high-income countries, but it is not known whether the risks are also increasing in low- and middle-income countries.
objective
To investigate the relationship between sedentary time and mortality and major cardiovascular disease in countries at different economic levels using data from the Prospective Urban Rural Epidemiology study.
Design, setting and participants
See also
This population-based cohort study included participants aged 35 to 70 years recruited from January 1, 2003 and followed up to August 31, 2021 in 21 high-, middle- and low-income countries with a mean follow-up of 11.1 years.
exposures
Daily sitting time measured using the International Physical Activity Questionnaire.
Main results and actions
The combination of all-cause mortality and major cardiovascular disease (defined as cardiovascular death, myocardial infarction, stroke, or heart failure).
Results
Of 105,677 participants, 61,925 (58.6%) were women and the mean age (SD) was 50.4 (9.6) years. During a median follow-up of 11.1 (IQR, 8.6-12.2) years, 6233 deaths and 5696 major cardiovascular events (2349 myocardial infarctions, 2966 strokes, 671 heart failure and 1792 cardiovascular deaths) were documented. Compared to the reference group (< 4 hours sitting per day), longer sitting time (≥ 8 hours per day) was associated with an increased risk for the combined outcome (hazard ratio). [HR], 1.19; 95% CI, 1.11-1.28; Pfor trend < 0.001), all-cause mortality (HR, 1.20; 95% CI, 1.10-1.31; Pfor trend < 0.001) and major cardiovascular disease (HR, 1.21; 95% CI, 1.10-1.34; Pfor trend < 0.001).
When stratified by country income, the association between sitting time and composite outcome was stronger in low- and middle-income countries (≥8 hours per day: HR, 1.29; 95% CI, 1.16–1.44) than in Low-income countries, high- and middle-income countries (HR, 1.08; 95% CI, 0.98-1.19; Pfor interaction = 0.02). Compared to those who reported sitting less than 4 hours per day and a high level of physical activity, participants who sat 8 or more hours per day had a 17% to 50% greater associated risk for the composite outcome across all physical activity levels; and the risk was attenuated along with increased physical activity.
Conclusions and Relevance
High sedentary times have been associated with an increased risk of all-cause mortality and cardiovascular disease in economically diverse settings, particularly in low- and middle-income countries. Reducing sedentary time along with increasing physical activity could be an important strategy to reduce the global burden of premature death and cardiovascular disease.
