Effects of Interrupting Sedentary Behavior on Metabolic and Cognitive Outcomes in Children
Prevention of pediatric obesity and its complications are U.S. public health priorities.
Promoting physical activity has been proposed as an intervention strategy. Apart from
reducing excessive weight, physical activity improves cardiovascular fitness, insulin
sensitivity, and academic performance. However, emerging evidence in adults suggests that
increased physical activity may not entirely counteract the negative health effects of a
Sedentary behavior is defined as a set of low-intensity activities involving limited body
movement (e.g.: TV viewing, prolonged sitting). TV viewing is associated with lower
cognitive functioning and depressive symptoms. Some studies found higher levels of childhood
sedentary behavior predicted higher body mass index (BMI) and cholesterol in adulthood,
suggesting that negative health consequences may begin early. Dunstan et al. conducted the
first lab-based study in adults investigating interrupting prolonged sedentary behavior with
physical activity breaks. The authors found that for overweight adults, adding 2-minute
moderate-intensity walking breaks every 20 minutes reduced postprandial insulin and glucose
responses by 23.0% and 29.6%, respectively. Thus, interrupting sedentary behavior may be an
intervention strategy to reduce health risks.
In children, cross-sectional observational studies indicate that sedentary behavior patterns
characterized by short bouts of activity are not associated with increased cardiometabolic
risk. However to date, no in-lab studies have manipulated sedentary behavior in children.
Therefore, we propose to conduct a randomized crossover pilot feasibility study to assess
whether interrupting sedentary behavior influences metabolic and executive function,
attention, mood, anxiety, and dietary intake. Children, ages 7-11 years, will complete two
conditions in random order: 3 hours of prolonged sitting and 3 hours of sitting interrupted
with 3 minutes of moderate-intensity walking every 30 minutes. The specific aim of this
project is to investigate whether interrupting sedentary behavior improves metabolic
parameters and changes executive function, attention, mood, anxiety, and dietary intake. The
primary hypothesis is that postprandial insulin incremental area under the curve (iAUC) will
be lower in the interrupted sitting vs. the prolonged sitting condition. The exploratory
secondary hypotheses are that glucose iAUC, executive function, attention, mood, anxiety,
and dietary intake will differ between the two conditions.
This project will investigate if interrupting sedentary time affects potential negative
health consequences of sedentary behavior in children. If interrupting sedentary time in
short bouts has beneficial effects among children, interventions examining the frequency,
duration, and intensity of such interruptions could be developed. Thus, these results have
the potential to provide insight into novel behavioral intervention targets in youth.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
Lower insulin incremental area under the curve (iAUC) during 3 hours after the OGTT.
Jack A Yanovski, M.D.
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
United States: Federal Government
|National Institutes of Health Clinical Center, 9000 Rockville Pike||Bethesda, Maryland 20892|