Associated factors in high blood pressure among schoolchildren in a middle size city, southern Brazil.

OBJECTIVE: To establish the prevalence of high blood pressure and associated factors among schoolchildren from Caxias do Sul, state of Rio Grande do Sul, Brazil.

METHODS: This school-based cross-sectional study assessed boys and girls aged 7 to 12 years from private and public schools. Three measurements of the children's blood pressure were taken during one visit to the schools. Weight, height, and waist circumference were measured. We also assessed the children's aerobic capacity (9-minute running test) and socioeconomic status. Statistical analysis was carried out using the chi-square test and logistic regression in order to control for confounding factors.

RESULTS: The sample included 1,413 children. Prevalence of schoolchildren with high blood pressure was 13.8% (systolic, diastolic, systolic/diastolic), and the proportion was higher (double) for obese and/or overweight children in comparison to normal-weight children. Children with increased waist circumference had 2.8 times greater chance of having high blood pressure levels than those with appropriate waist circumference (95% confidence interval 2.513-3.186 and p = 0.000). Individuals belonging to a high social class, defined according to the Brazilian National Economic Index, had 2.6 times greater chance of having high blood pressure.

CONCLUSIONS: In the present study, schoolchildren aged 7 to 12 years from Caxias do Sul had high prevalence of high blood pressure levels; increased waist circumference, high socioeconomic status, and low physical capacity were associated with this condition. We suggest that measures be taken to promote the practice of physical activity and dietary control to improve blood pressure levels and thus reduce risk factors.