Reconsidering the sedentary behaviour paradigm

PLoS One. 2014 Jan 15;9(1):e86403. doi: 10.1371/journal.pone.0086403. eCollection 2014.

Abstract

Aims: Recent literature has posed sedentary behaviour as an independent entity to physical inactivity. This study investigated whether associations between sedentary behaviour and cardio-metabolic biomarkers remain when analyses are adjusted for total physical activity.

Methods: Cross-sectional analyses were undertaken on 4,618 adults from the 2003/04 and 2005/06 U.S. National Health and Nutrition Examination Survey. Minutes of sedentary behaviour and moderate-to-vigorous physical activity (MVPA), and total physical activity (total daily accelerometer counts minus counts accrued during sedentary minutes) were determined from accelerometry. Associations between sedentary behaviour and cardio-metabolic biomarkers were examined using linear regression.

Results: Results showed that sedentary behaviour was detrimentally associated with 8/11 cardio-metabolic biomarkers when adjusted for MVPA. However, when adjusted for total physical activity, the associations effectively disappeared, except for C-reactive protein, which showed a very small, favourable association (β = -0.06) and triglycerides, which showed a very small, detrimental association (β = 0.04). Standardised betas suggested that total physical activity was consistently, favourably associated with cardio-metabolic biomarkers (9/11 biomarkers, standardized β = 0.08-0.30) while sedentary behaviour was detrimentally associated with just 1 biomarker (standardized β = 0.12).

Conclusion: There is virtually no association between sedentary behaviour and cardio-metabolic biomarkers once analyses are adjusted for total physical activity. This suggests that sedentary behaviour may not have health effects independent of physical activity.

MeSH terms

  • Accelerometry
  • Adult
  • Biomarkers / blood
  • Blood Glucose
  • Blood Pressure
  • Cholesterol, HDL / blood
  • Cross-Sectional Studies
  • Female
  • Humans
  • Insulin / blood
  • Linear Models
  • Male
  • Middle Aged
  • Motor Activity
  • Risk Factors
  • Sedentary Behavior*
  • Triglycerides / blood
  • Waist Circumference
  • Young Adult

Substances

  • Biomarkers
  • Blood Glucose
  • Cholesterol, HDL
  • Insulin
  • Triglycerides

Grant support

The authors have no support or funding to report.