CVD risk from prolonged occupational sitting attenuated by additional physical activity – Evidence from a prospective cohort of 481,688 Asian adults

BackgroundFor the first time, the 2020 WHO guidelines on physical activity recommend reducing sedentary behaviors due to their health consequences. Less is known on the effect of prolonged occupational sitting, especially in the context of low physical activity engagement.This study aims at quantifying cardiovascular risk associated with prolonged occupational sitting and determining the additional amount of physical activity that may be needed to attenuate it.MethodsA cohort comprising 481,688 participants in a health surveillance program in Taiwan was followed between 1996 and 2017, collecting data on occupational sitting time, leisure-time physical activity (LTPA) habits, lifestyle, and metabolic parameters. The all-cause and expanded cardiovascular disease (CVD + diabetes mellitus + kidney disease) mortality associated with three occupational sitting volumes (mostly sitting, alternating sitting and non-sitting, mostly non-sitting) was analyzed applying multivariate Cox regression models to calculate the hazard ratios (HRs) for all participants and by subgroups, including five levels of LTPA. Deaths in the first two years of follow-up were excluded to avoid reverse causality.ResultsThe study recorded 26,257 deaths during a mean follow-up period of 12.85 years. Individuals mostly sitting at work had a higher mortality risk than those mostly non-sitting, both from all causes (HR: 1.16, 95% CI: 1.11-1.20) and from expanded CVD (HR:1.46, 95% CI:1.35-1.58), after adjusting for gender, age, education, smoking, drinking, and body mass index. Individuals alternating sitting and non-sitting at work did not experience increased risk for all-cause mortality, compared to individuals mostly non-sitting at work (HR: 1.01, 95% CI: 0.97-1.05), but did experience higher risk of deaths due to expanded CVD (HR: 1.13, 95% CI: 1.04-1.23). Individuals engaged in low (15-29 min/day) or no (<15 min/day) LTPA, who mostly sit at work, would need to increase their LTPA by 15 and 30 minutes respectively to reduce their risk of mortality to that of similarly inactive individuals who mostly do not sit at work.ConclusionsAs part of modern lifestyles, prolonged occupational sitting is considered normal and has not received due attention, even though its deleterious effect has been largely proved. Alternating sitting and non-sitting at work, as well as an extra 15 to 30 min/day of LTPA, can attenuate the harms of prolonged occupational sitting. Thus, emphasizing the associated harms and suggesting workplace system changes could help the society to de-normalize this common behavior, similarly to the process of de-normalizing smoking.

Association Between Occupational Sitting With High Sensitivity C-Reactive Protein: The Jackson Heart Study

Modifiable, behavioral risk factors like occupational sitting may contribute to inflammation, an important cardiovascular risk factor. This study evaluated the association of self-reported occupational sitting with changes in c-reactive protein (CRP) and the role of sex. We examined occupational sitting and baseline CRP levels for 2889 African American participants in the Jackson Heart Study. Four multivariable linear regression models were estimated to determine the association of occupational sitting and CRP. Analyses were conducted in 2020. The mean age was 50.8 years and 61% were female. Participants who reported occupational sitting as “often/always” had CRP levels of 4.9±6.8 mg/L, “sometimes” had levels of 4.8±8.1 mg/L, and “never/seldom” had levels of 4.3±6.8 mg/L. In the unadjusted model, “often/always” engaging in occupational sitting was significantly associated with higher levels of CRP when compared to “never/seldom” ( P < .05). This differed by sex with female participants who reported “often/always” occupational sitting had CRP levels of 6.0±7.6 mg/L compared to only 5.1±6.9 mg/L for “never/seldom.” Neither the overall association nor the female-specific association remained statistically significant in the adjusted models. We found an association between occupational sitting and inflammation, measured by CRP. This association varied by sex but did not remain significant after fully adjusting for covariates.

Evaluation of a natural workspace intervention with active design features on movement, interaction and health

BACKGROUND: There is increasing focus on designing workspaces that promote less sitting, more movement and interaction to improve physical and mental health. OBJECTIVE: This study evaluates a natural intervention of a new workplace with active design features and its relocation to a greener and open space. METHODS: An ecological model was used to understand how organisations implement change. Pre and post survey data from 221 matched cases of workers and accelerometery data (n = 50) were analysed. RESULTS: Results show a decrease in occupational sitting (-20.65 mins/workday, p = 0.001) and an increase in workplace walking (+5.61 mins/workday, p = 0.001) using survey data, and accelerometery data (occupational sitting time: –31.0 mins/workday, p = 0.035, standing time: +22.0 mins/workday, p = 0.022, stepping time: +11.0 mins/workday, p = 0.001). Improvements in interaction, musculoskeletal pain and mental health were reported. CONCLUSIONS: Application of the ecological model shows that the organisation understands how to target the built environment and social/cultural environment but not how to target behaviour change at the individual level.

Occupational sitting time, its determinants and intervention strategies in Malaysian office workers: a mixed-methods study

Adults who accumulate a lot of sedentary time per day are at an increased risk of metabolic syndrome, type 2 diabetes, and hypertension. Prolonged sitting is also associated with depression, anxiety, bipolar disorder and schizophrenia. With the increase in desk-based office work, many office workers spend long hours sitting at the workplace. The aim of this study was to assess occupational sitting time in Malaysian government office workers, and investigate determinants of occupational sitting time and potential strategies to interrupt sitting time. We conducted a mixed-methods study consisting of a survey and focus group discussions (FGDs). A total of 1338 office workers from 24 Malaysian ministries completed the Occupational Sitting and Physical Activity Questionnaire. Twenty-nine office workers who spent at least 7 h per day sitting at work participated in FGDs. We enquired about knowledge, awareness and perceptions related to prolonged sitting time, barriers and facilitators to sitting time at work, and potential intervention strategies. Mean daily sitting time at work was 5.96 h (standard deviation = 1.37 h). FDGs confirmed barriers and facilitators to sitting time in accordance with the social-ecological model for health. Intrapersonal, social and physical environmental factors as well as organizational culture and organizational policy were mentioned to affect occupational sitting time. The results show that Malaysian government office workers spent a significant amount of time sitting at work and we identified multi-level factors influencing sitting time. A smartphone-based intervention to interrupt sitting time at work was suggested and is currently being tested.