Blood pressure levels in childhood: probing the relative importance of birth weight and current size.

Several studies have reported data supporting the idea that an impaired intrauterine environment that deprives the fetus of optimal nutrient delivery results in the predisposition of the fetus to experience cardiovascular and metabolic dysfunction in later life. However, contradictory data still exist. Our purpose was to investigate the effects of both birth weight and weight gain on the risk for high blood pressure levels in 6- to 10-year-old children. This cross-sectional study included 739 children divided into quartiles of birth weight. The mean values of both systolic and diastolic pressure were significantly different between quartiles of birth weight, with increasing blood pressure values as the birth weight decreased (P<0.001). Covariance analysis adjusting for gender, prematurity, and body mass index (BMI) showed that both systolic and diastolic pressure remained greater in the lowest than in the highest birth weight quartile. Separating those with low and normal birth weight demonstrated that the risk of childhood hypertension was significantly higher among children with low birth weight and current obesity (odds ratio [OR]: 5.0, confidence interval [CI]: 3.3 to 16.1; P=0.023). The inverse association between birth weight and blood pressure levels appears to be programmed during fetal life, while weight gain during childhood adds to this risk.