Intima-Media Thickness in 11- to 13-Year-Old Children: Variation Attributed to Sedentary Behavior, Physical Activity, Cardiorespiratory Fitness, and Waist Circumference.

Background: It is unclear how sedentary behavior (SED), physical activity (PA), and cardiorespiratory fitness (CRF) influence vascular structure in children of varying body size. This study examined whether associations between SED, PA, and CRF with intima-media thickness (IMT) added to that of abdominal fatness and IMT. Differences in physiological measures among waist circumference (WC) percentiles were tested. Methods: We assessed IMT of the carotid artery in 265 children aged 11 to 13 years (135 girls). Measures included IMT assessed with high-resolution ultrasonography, WC, body fat mass (BFM) from DXA, and CRF determined using a maximal cycle test. SED and PA were assessed by accelerometry. Association between IMT and CRF adjusted for PA variables, and body composition phenotypes were tested with multiple linear regression analysis. Results: CRF was related to IMT independently of moderate to vigorous PA (MVPA) and SED (P < .05). When WC was added to the model CRF was no longer associated with IMT (P > .05). Children in the higher WC group had increased mean values of BMI, BFM, WC, and IMT and lower MVPA and CRF (P < .05). Conclusion: Full modeling of SED, MVPA, CRF, and WC revealed that regional adiposity appears to have the biggest role in arterial structure of children. [ABSTRACT FROM AUTHOR]