Abstract
Obesity is associated with comorbidities, including hypertension, which have been diagnosed in the pediatric population. The aim of this study was to verify the mediator role of physical activity in the relationship between anthropometric indicators and blood pressure (BP) in children with normal weight and children with overweight/obesity. The BeE-school project included 728 Portuguese children (376 boys, 352 girls), aged 6 to 10 years old, who were divided into two groups: children with normal weight and children with overweight/obesity, according to body mass index z-score (BMI-z). Body mass, height, waist circumference (WC), systolic BP (SBP) and diastolic BP (DBP) were assessed. Tri-ponderal mass index (TMI), waist-to-height ratio (WHtR) and mean BP (MBP) were calculated. Sedentary behavior and moderate-to-vigorous physical activity (MVPA) were determined by accelerometry. Mediation analyses were conducted considering predictors (WC, WHtR, TMI), mediators (MVPA on weekdays, weekend, total), outcomes (SBP, DBP, MBP). Children with overweight/obesity had higher mean values for BP measurements compared to their normal weight peers. In the correlations were not observed associations between anthropometric indicators and BP variables in children with normal weight, but MVPA on weekdays and MVPA total showed positive associations with SBP. However, children with overweight/obesity presented significant positive associations between all anthropometric indicators and BP variables. The present study provides evidence that physical activity functions as a competitive mediator in relationship between TMI and BP in children with overweight/obesity. The overweight simultaneously elevates BP directly while reducing protective physical activity engagement in Portuguese children.