Volumes and bouts of sedentary behavior and physical activity: associations with cardiometabolic health in obese children

Objective: To examine associations of volumes and bouts of sedentary behavior (SED) and moderate-to-vigorous physical activity (MVPA) with individual and clustered cardio-metabolic outcomes in overweight/obese children. Design and Methods: Cross-sectional data from 120 overweight/obese children (8.3±1.1y, 62% girls, 74% obese) with SED and MVPA assessed using accelerometry. Children were categorised into quartiles of mean bouts.day-1 of SED (10, 20, and 30min) and MVPA (5, 10, and 15min). Associations with triglycerides, HDL cholesterol, glucose, insulin, systolic/diastolic blood pressure, and clustered cardio-metabolic risk (cMet) were examined using linear regression, adjusted for confounders. Results: Independent of MVPA, SED volume was inversely associated with HDL cholesterol (β [95% CI] =-0.29 [-0.52, -0.05]). MVPA volume was inversely associated with diastolic blood pressure, independent of SED (β=-0.22 [-0.44, -0.001]), and cMet (β=-0.19 [-0.36, -0.01]) although not after adjustment for SED (β=-0.14 [-0.33, 0.06]). Independent of MVPA and SED volumes, participants in the highest quartile of 30min bouts.day-1of SED had 12% lower HDL cholesterol than those in the lowest quartile (d=0.53, p=0.046, ptrend=0.11). Conclusions: In addition to increasing MVPA, targeting reduced SED and limiting bouts of SED to/obese children.