Low cardiorespiratory fitness combined with excess adiposity is associated with elevated diastolic blood pressure in Brazilian children

Objective: To describe indicators of physical fitness, general and central adiposity, and blood pressure (BP) in schoolchildren aged 6-10 years in Curitiba (Brazil), comparing according to sex, BP status, adiposity, and physical fitness, and analyzing the combined effect of cardiorespiratory fitness (CRF) and adiposity in relation to BP levels. Methodology: Cross-sectional study with 167 children aged 6-10 years. Body mass, height, waist circumference (WC), systolic BP (SBP), and diastolic BP (DBP) were measured. Body mass index (BMI), BMI z-score (BMI-z), Tri-ponderal mass index (TMI), waist-to-height ratio (WHtR), and mean BP (MBP) were calculated. Physical fitness was assessed by handgrip strength, horizontal jump, and 20-meter shuttle run test. Adiposity was classified as normal or excessive (BMI, TMI, WC, WHtR). Hypertension was defined as BP values ≥P95 for sex and height. Analysis was performed using t-tests, chi-square tests, kruskal–wallis test and binary logistic regression. Results: Girls had higher body mass (p=0.038) and SBP (p=0.012) than boys. Frequencies of excess general adiposity (BMI-z=40.1%), central adiposity (WHtR=50.3%), and hypertension (17.4%) showed no differences between sexes. Children with high BP had higher means and frequencies of excessive adiposity (p<0.05) and low CRF (p=0.015). Hypertensive measures were associated with TMI (OR=3.15), WC (OR=2.92), WHtR (OR=2.77), and low CRF (OR=3.20) (p<0.05). Children with low CRF combined with high WC or TMI presented higher DBP and MBP than those with high CRF, regardless of adiposity classification (p<0.01). Conclusions: Children with high BP and hypertension had more general and central adiposity, and low CRF. The combination of low CRF and high adiposity was associated with higher DBP and MBP. Assessments in schoolchildren are important for identifying health risk factors, providing a basis for comprehensive preventive actions.