The Relationship Between Birth Weight and Blood Pressure in Childhood: A Population-Based Study

BACKGROUND Low birth weight has been associated with increased risk of hypertension later in life. The aim of this study was to evaluate the association between birth weight and blood pressure (BP) in healthy 9- to 10-year-old Icelandic children. METHODS Each child underwent 4 seated BP measurements, and the BP percentile was calculated from the mean of the 4 measurements. Height and weight were measured and birth weight retrieved from the Icelandic Birth Registry. Birth measures and anthropometric data were correlated with BP and BP percentiles. Multivariable linear regression was employed to examine the association between BP and birth measures. RESULTS Of 857 children with complete data, 445 were female (51.9%). The mean BP was 112/64 mm Hg in males and 111/63mm Hg in females. The mean birth weight was 3714±620g. No correlation was found between birth weight and absolute BP values. A significant negative correlation between birth weight and both systolic (r = -0.09, P = 0.005) and diastolic (r = -0.08, P = 0.014) BP percentiles was observed. Gestational age did not correlate with BP. CONCLUSION In contrast to many previous studies, we found no association between birth weight and absolute BP in children. However, we observed a statistically significant negative correlation between birth weight and BP percentiles. The lack of standardized BP values may partly explain the conflicting results of previous studies in children, and we suggest that BP percentiles be examined more thoroughly in association with birth weight.