Elevated Blood Pressure in Rural Versus Urban School Children of Southeastern Brazil

There is evidence of increased blood pressure in children, although little studied in developing countries and rural areas. This study compared urban and rural differences in blood pressure and associated factors among children 7-10 years old. Cross-sectional study in 73 elementary schools of two municipalities in southeastern Brazil. Blood pressure was measured using an automatic device. BP levels were classified as being normal, borderline and high. Trained staff collected anthropometric data and skin color. The multivariate linear regression model included body mass index, age and skin color as confounding variables. A total of 2183 children (55% girls, 51.4% white, 58.7% living in urban areas) were studied. The prevalence of high blood pressure was 7.2% (6.3% in urban vs. 8.4 in rural, p=0.026). Obesity was detected in 7.3% (9% in urban vs. 5% in rural, p<0.001). Children living in rural areas have a systolic blood pressure 2.3 mmHg higher than children who live in urban areas. Similar difference was also found for diastolic blood pressure. The results confirm that age and overweight are associated with elevated blood pressure in children. It is possible that the white-coat effect is more frequent among rural children. Salt intake should be included in future studies.