Key points Ask Is daily sitting time associated with mortality and cardiovascular diseases (CVD) in countries of different economic levels? Findings In this cohort study that included 105,677 participants from 21 countries , increased sitting time was associated with increased risk of all-cause mortality and serious CVD, and the association was most pronounced in low- and lower-middle-income countries. Adhering to the World Health Organization’s recommendations for physical activity could effectively mitigate the risk of prolonged sitting. Which means that reducing sedentary time along with increasing physical activity may be an important strategy to alleviate the global burden of premature deaths and cardiovascular diseases. |
Importance
A high amount of sitting time is associated with increased risk of cardiovascular disease (CVD) and mortality in high-income countries, but it is unknown whether risks also increase in low- and middle-income countries.
Aim
To investigate the association of sitting time with mortality and major cardiovascular diseases in countries of different economic levels using data from the Prospective Urban Rural Epidemiological study.
Design, environment and participants
This population-based cohort study included participants aged 35 to 70 years recruited from January 1, 2003 and followed until August 31, 2021, in 21 high-, middle-, and low-income countries . with a median follow-up of 11.1 years.
Exhibitions
Daily sitting time measured using the International Physical Activity Questionnaire.
Main results and measures
The composite of all-cause mortality and major CVD (defined as cardiovascular death, myocardial infarction, stroke, or heart failure).
Results
Of 105,677 participants, 61,925 (58.6%) were women and the mean (SD) age 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 with the reference group (<4 hours per day of sitting), greater sitting time (≥8 hours per day) was associated with a higher risk of the composite outcome (hazard ratio [HR], 1 .19; 95% CI, 1.11-1.28; P for trend < 0.001), all-cause mortality (HR, 1.20; 95% CI, 1.10-1.31; P for trend < 0.001) and major CVD (HR, 1.21; 95% CI, 1.10-1.34); p for trend < .001).
When stratified by country income levels , the association of sitting time with the composite outcome was strongest in low- and lower-middle-income countries (≥8 hours per day: HR, 1.29; 95% CI, 1 .16-1.44) compared with high- and upper-middle-income countries (HR, 1.08; 95% CI, 0.98-1.19; P for interaction = 0.02).
Compared with those who reported sitting less than 4 hours per day and a high level of physical activity, participants who sat for 8 or more hours per day experienced a 17% to 50% higher associated risk of the composite outcome in all levels of physical activity; and the risk attenuated along with increasing physical activity levels.
Conclusions and relevance
- A high amount of sitting time was associated with an increased risk of all-cause mortality and CVD in economically diverse settings, especially in low- and lower-middle-income countries.
- Reducing sedentary time along with increasing physical activity could be an important strategy to alleviate the global burden of premature deaths and CVD.
