RESUMO
OBJECTIVE: To examine the associations of objectively measured sedentary time and television (TV) viewing time with emerging inflammatory and endothelial function markers in adolescents. STUDY DESIGN: This study comprised 183 adolescents (88 girls), aged 13 to 17 years. Sedentary time and moderate-to-vigorous physical activity was objectively measured with accelerometry, whereas TV viewing time was self-reported. White blood cell counts and levels of C-reactive protein, complement factors C3 and C4, interleukin-6, adiponectin, leptin, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, E-selectin, L-selectin, and plasminogen activator inhibitor-1 were measured in fasted blood samples. RESULTS: Sedentary time was not significantly associated with any of the examined cardiometabolic markers after controlling for potential confounders. However, TV viewing time was positively associated with soluble endothelial adhesion molecules intercellular adhesion molecule 1 (standardized ß = 0.19, P = .008), vascular cell adhesion molecule 1 (ß = 0.17, P = .020), L-selectin (ß = 0.18, P = .013), and E-selectin (ß = 0.16, P = .023) concentrations, after controlling for sex, age, pubertal status, moderate-to-vigorous physical activity, body mass index, and total sedentary time. CONCLUSIONS: High TV viewing time may play a key role in cardiovascular and metabolic diseases through the cell adhesion molecules in adolescence.
Assuntos
Doenças Cardiovasculares/sangue , Doenças Metabólicas/sangue , Comportamento Sedentário , Televisão , Adolescente , Biomarcadores/sangue , Feminino , Humanos , Masculino , Televisão/estatística & dados numéricos , Fatores de TempoRESUMO
OBJECTIVES: To examine the combined influence of physical activity and screen time (television and video games) on the odds of being overweight and to evaluate the utility of current public policy recommendations. STUDY DESIGN: Physical activity was assessed by a pedometer and screen time was assessed by survey in a sample of 709 children age 7 to 12 years. The percentage of subjects meeting current physical activity and screen time recommendations was calculated. Cross-tabulated physical activity-screen time groups were formed depending on whether or not the children were meeting current recommendations. Logistic regression was used to examine the influence of physical activity and screen time on the odds of being overweight. RESULTS: Children meeting physical activity and screen time recommendations were the least likely to be overweight. Approximately 10% of the boys and 20% of the girls meeting both recommendations were overweight, compared with 35% to 40% of those who did not meet either recommendation. Screen time and physical activity appeared to be equivalent risk factors for boys, even though physical activity in girls was more strongly associated with body mass index. CONCLUSIONS: Children not meeting the physical activity or screen time recommendations were 3 to 4 times more likely to be overweight than those complying with both recommendations.