Is breastfeeding protective for blood pressure in schoolchildren? A cohort study in northeast Brazil.

Abstract

This study assessed the influence of breastfeeding and nutritional status of full-term infants on blood pressure at school age. This was a cross-sectional study nested in a cohort of 375 infants recruited at birth between 1993 and 1994 in the state of Pernambuco, Brazil. A sample of 213 8-year-old children had their blood pressure measured. A multivariate linear regression analysis was used to identify the influence of low birth weight and breastfeeding duration on blood pressure, adjusting for socioeconomic conditions, maternal nutritional status, eating habits, growth rate (0-6 months), and the children's anthropometry at 8 years. Mean values of children's blood pressure were significantly higher with lower duration of breastfeeding. Higher per capita family income, maternal body mass index and height, child's weight and length at birth, and child anthropometric dimensions at 8 years of age were associated with higher levels of blood pressure. The multivariate linear regression analysis showed that children who were breastfed for less than 40 days had higher systolic blood pressures, explaining 2.2% of its variation. Anthropometry at 8 years of age explained the higher variance in systolic blood pressure (12.6%) with emphasis on waist circumference (9.5%), followed by per capita income (3.2%) and maternal height (2.1%). Birth weight and length had no influence on blood pressure levels in this age group. Children's waist circumference, duration of breastfeeding, socioeconomic conditions, and maternal nutritional status influenced blood pressure levels of schoolchildren born full term, rather than low birth weight.