Relationship of Objectively Measured Physical Activity, Sedentary Behavior and Sleep Time with Cardiovascular and Mtabolic Outcomes in Adolescents (A Pilot Study): ABCD Growth Study.

STUDY OBJECTIVE: Different behaviors are considered important factors that may influence a healthy lifestyle. Given this fact, we aim to analyze the relationship between moderate-vigorous physical activity (MVPA), sleep time, and sedentary time, with cardiometabolic outcomes in adolescents. METHODS: Cross-sectional study, with 152 eutrophic and healthy adolescents. The behavioral variables were collected objectively and the arterial thickness was measured through ultrasound. Blood variables (LDL, TG, HDL, glucose, and insulin) were collected in a private laboratory. To analyze the data, the Student t test and Kruskal-Wallis test were used to compare the groups. All analyses adopted p < 0.05. RESULTS: Girls who demonstrated better combined behaviors, presented significant results for TG (p = 0.045), BP (p = 0.016), and cardiovascular score (p = 0.049) when compared to their peers. Furthermore, the practice of physical activity combined with sufficient sleep time was associated with lower values of arterial thickening (p = 0.017). CONCLUSIONS: In view of the results presented, it is possible to state that the aggregation of behaviors was more consistent in females and that the practice of physical activity and adequate sleep time can reflect on cardiovascular health.

Physical Activity and Skipping Breakfast Have Independent Effects on Body Fatness Among Adolescents.

OBJECTIVE: We analyzed the longitudinal relationship between breakfast intake and adiposity among adolescents, and the possible mediation role of physical activity on this phenomenon. METHODS: We conducted the longitudinal study composed of 86 adolescents (11-14 years old), absence of any known chronic diseases and no regular medicine use that returned the formal consent and assent both signed. Breakfast intake was reported through face-to-face interviews. Adiposity was assessed using a densitometry scanner. Physical activity was estimated through step counts performed using pedometers. Biological maturation was estimated through the maturity level. Student t test for independent samples was used to compare adolescents who were "nonskipping breakfast" and "skipping breakfast," whereas the relationship between adiposity, physical activity, and skipping breakfast was assessed using Pearson correlation. Structural equation model was created to identify the mediation role of physical activity on the relationship between nonskipping breakfast and adiposity. RESULTS: After 12 months, adolescents who had consumed breakfast regularly presented decreased trunk fatness (-3.5% [95% confidence interval (CI): -6.9 to -0.2]) and body fatness (-2.3% [95% CI: -3.9 to -0.7]) compared with their counterparts. Physical activity had an inverse relationship with trunk fatness (r = -0.270 [95% CI: -0.457 to -0.060]). Nonskipping breakfast was, however, not significantly related to trunk fatness; however, physical activity seems to reduce trunk fatness in our sample (r = -0.281; 95% CI: -0.479 to -0.083). CONCLUSIONS: Adolescents who ate breakfast regularly presented lower body fatness independent of physical activity, whereas trunk fatness decreased in adolescents who improved physical activity.