A large-scale study using wearable device data found standing did not appear to reduce cardiovascular disease risk and may have increased the risk of orthostatic circulatory diseases.
The research, published in the International Journal of Epidemiology, provided new insights into the health impacts of sitting and standing behaviors. Researchers analyzed data from 83,013 UK Biobank participants who wore wrist accelerometers for 7 days. They examined associations between daily time spent sitting, standing, and overall stationary behavior with incident cardiovascular disease and orthostatic circulatory disease over an average 6.9-year follow-up period.
The study revealed standing time was not associated with reduced CVD risk at any duration. Standing more than 2 hours per day was associated with increased risk of orthostatic circulatory disease, with risk increasing by 11% for every additional 30 minutes.
Sitting time above 10 hours per day was associated with increased risk of both CVD and orthostatic circulatory disease. For CVD, risk increased by 15% for each hour of sitting beyond 10 hours daily, while risk for orthostatic circulatory disease increased by 26% for each additional hour beyond 10 hours.
This research represented one of the largest wearable device-based studies examining these relationships, with distinct measurements of sitting and standing time. Previous studies often relied on self-reported data or used devices that could not differentiate between sitting and standing postures.
The researchers suggested the absence of ambulatory movement during both sitting and standing may contribute to circulatory issues. They emphasized strategies to reduce cardiovascular risk should focus on increasing overall physical activity rather than replacing sitting with standing.
The study adjusted for various confounding factors including age, sex, ethnicity, smoking history, alcohol consumption, body mass index, education, diet, family history of CVD, and medication use. The researchers also conducted sensitivity analyses to account for potential reverse causation.
While the observational nature of the study precluded causal inferences, the authors noted that their findings had potential implications for workplace health recommendations and patient care strategies, particularly for those at high risk of CVD.
The study's limitations included potential misclassification of posture inherent to wrist-worn devices, although daily estimates were similar to those from gold-standard thigh-worn devices in other UK cohorts. Additionally, the UK Biobank's low response rate may have affected generalizability, though previous research suggested this does not substantially influence associations between lifestyle factors and disease risk.
The authors suggested that while reducing excessive sitting time remains an important strategy for cardiovascular health, promoting standing alone may not be sufficient and could potentially increase risk of certain circulatory conditions. They emphasized the need for strategies encouraging overall movement and physical activity throughout the day.
The authors declared having no competing interests.