This study aimed to analyze the associations between sedentary behavior, physical activity (PA), and cardiorespiratory fitness (CRF), with carotid intima-media thickness (cIMT), a marker of atherosclerosis already present at an early stage among obese adolescents. The associations between anthropometric measures, sedentary time, PA, CRF, and cIMT of 54 Caucasian obese adolescents were analyzed using partial correlations (controlling for age and sex) and multiple linear regressions. Differences between participants with and without a healthy CRF were also analyzed using independent sample t test. Sedentary time did not correlate with any of the variables. Light physical activity correlated positively with mean cIMT (r(38) = 0.36, p = 0.024). Moderate physical activity (MPA) correlated positively with both mean (r(38) = 0.37, p = 0.018) and maximum (r(38) = 0.33, p = 0.039) cIMT. CRF was inversely associated with mean cIMT (r(40) = -0.36, p = 0.019), even when controlling for sedentary time (r(37) = -0.35, p = 0.030). The best predictors of cIMT were MPA and weight. No significant differences in cIMT were found between participants with healthy and unhealthy CRF.
Conclusion: Although we need to be cautious due to the limitations of the study, the results suggest that despite the importance of decreasing sedentary time, increasing PA intensity may be more effective in improving endothelial structural health among obese adolescents.
Trial registration: ClinicalTrials.gov NCT02024061.
Keywords: Cardiorespiratory fitness; Carotid intima-media thickness; Obese adolescents; Physical activity; Sedentary behavior.