Atherosclerosis Prevention in Adolescents with Obesity: The Role of Moderate–Vigorous Physical Activity

Carotid intima–media thickness (cIMT) is a subclinical marker of atherosclerotic development, which is impaired in adolescents with obesity. This study aimed to analyze the impact of physical activity (PA), cardiorespiratory fitness (CRF), body mass index (BMI), and body composition changes on the cIMT of adolescents with obesity. Longitudinal data (6 months) from adolescents aged 12–18 years, with a BMI ≥97th percentile, previously recruited for the non-randomized controlled trial PAC-MAnO (Clinicaltrials.gov-NCT02941770) were analyzed using partial correlations controlling for sex and pubertal status and multiple regressions. A total of 105 adolescents (51.4% girls, 86.7% Caucasian), 14.8 ± 1.8 years old, with a BMI z-score of 3.09 ± 0.74 were included. Total body fat mass (TBFM) (F(1,91) = 23.11, p < 0.001), moderate–vigorous PA (MVPA) (F(1,91) = 7.93, p = 0.0006), and CRF (mL/kg/min) (F(1,90) = 19.18, p < 0.001) predicted cIMT variance with an R2 of 0.24, 0.09, and 0.23, respectively. MVPA changes showed a high correlation with CRF variation (r(91) = 0.0661, p < 0.001). This study suggests that although cIMT is impaired in overweight adolescents, improvements in TBFM, MVPA, and CRF are associated with cIMT improvement. Although both energy intake and MVPA may influence TBFM, MVPA plays the most relevant role in cIMT development due to its direct association with CRF.