Sedentary Behavior as an Independent Factor
Physical activity plays an important role in the overall health of an individual. It has been established that physical activity is beneficial for eliminating the risk of death related to the sedentary time (Ekelund et al., 2016). However, the lifestyle of modern people involves a vast amount of time spent sitting, and a wide variety of professions and occupations demand different levels of immobility. Sedentary time can affect people’s health in many ways.
For example, sedentary behavior has been previously associated with an unhealthy diet in young people (Hobbs, Pearson, Foster, & Biddle, 2014). Therefore, it is crucial to study sedentary behavior as an independent factor influencing health outcomes.
A systematic review conducted by Biswas et al. (2016) provides a comprehensive analysis of the relationships between sedentary behavior and various health outcomes among adult people regardless of their physical activity levels. The authors hypothesized that sedentary time would be independently associated with cardiovascular and noncardiovascular outcomes. The introduction of the paper presents the purpose of the research and contains an explanation for the chosen approach: “studies suggest that long periods of sitting have deleterious health effects independent of adults meeting physical activity guidelines” (Biswas et al., 2016, p. 123). Moreover, the literature discussed in the beginning implies that physical activity and sedentary behavior could influence people’s health as mutually exclusive factors.
The Studies Reviewed and Data Analysis of Their Findings
Twenty thousand nine hundred eighty research papers were chosen from MEDLINE, PubMed, EMBASE, CINAHL, Cochrane Library, Web of Knowledge, and Google Scholar databases according to the inclusion and exclusion criteria. Authors selected articles that evaluated sedentary behavior in adult participants as the primary predictor, independent of physical activity, and correlated to at least one health outcome.
All of them were assessed for quality with the help of an evaluation tool previously validated and utilized by other researchers, and then data analysis was performed using Comprehensive Meta-analysis, version 2 (Biostat). Odds ratios, relative risk ratios, and HRs with associated 95% confidence levels were collected from papers for each outcome, if available. Most studies used prospective cohort designs, and 3 of them used cross-sectional and case-control study designs; all but one study used self-reported methods to collect data on participants’ sedentary behavior and physical activity.
Results showed that greater sedentary time was positively associated with an increased risk for all-cause mortality, cardiovascular disease mortality, cancer mortality, cardiovascular disease incidence, cancer incidence, and type 2 diabetes incidence even after statistical adjustment for physical activity. The most significant statistical effect was related to the risk of type 2 diabetes. Ten studies reported joint effects among sedentary time, physical activity, and health outcomes.
Within these ten studies, sedentary time was associated with a 30% lower relative risk for all-cause mortality among people with high levels of physical activity compared with people with low levels of physical activity. Therefore, the systematic review by Biswas et al. (2016) highlighted the importance of sedentary behavior as an independent factor and suggested that the degree of its negative influence might depend on the individual level of physical activity. An additional sensitivity analysis revealed that the chosen methods did not alter the statistical significance of the calculated results.
Few limitations of the study mentioned by the authors include the absence of the individual-level data, the selection of English articles exclusively, and the possible presence of publication bias. The findings of the paper are consistent with the denoted purpose and confirm the hypothesis proposed by the researchers. Sedentary behavior appears to be a substantial factor that can lead to adverse health outcomes among adult people independently of the level of their physical activity. Therefore, the reviewed article can be used as a source of practical information regarding health outcomes by medical workers and their patients.
Biswas, A., Oh, P. I., Faulkner, G. E., Bajaj, R. R., Silver, M. A., Mitchell, M. S., & Alter, D. A. (2015). Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults. Annals of Internal Medicine, 162(2), 123-132. Web.
Ekelund, U., Steene-Johannessen, J., Brown, W. J., Fagerland, M. W., Owen, M., Powell, K. E., … Lee, I.-M. (2016). Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women. The Lancet, 388(10051), 1302-1310. Web.
Hobbs, M., Pearson, N., Foster, P. J., & Biddle, S. J. H. (2014). Sedentary behaviour and diet across the lifespan: An updated systematic review. British Journal of Sports Medicine, 49(18), 1179-1188. Web.