Size at birth, infant growth, and blood pressure at three years of age.
OBJECTIVE
Our aim was to determine the extent to which infant growth-in weight-for-length-from birth to 6 months is associated with systolic blood pressure (SBP) at 3 years and to determine whether this association varies with birth size.


METHODS
In 530 children from the prospective cohort Project Viva, we measured birth length and 6-month weight and length with research standard instruments and SBP at age 3 years with a Dinamap automated recorder. We derived weight-for-length z-scores (WFL-z) and analyzed data with mixed effects regression models.


RESULTS
The mean (SD) WFL-z was 0.47 (0.75) at birth and 0.70 (0.96) at 6 months. Mean (SD) SBP at 3 years was 91.7 (9.4) mm Hg. After adjusting for confounding variables and birth WFL-z, child SBP was 1.0 mm Hg (95% CI 0.2, 1.8) higher for each z-score increment in 6-month WFL-z. The SBP of children in the lowest birth WFL-z quartile and the highest 6-month WFL-z quartile was 5.5 mm Hg (95% CI 2.6, 8.4) higher than that of children in the highest birth and lowest 6-month WFL-z quartiles.


CONCLUSIONS
More rapid increase in weight-for-length, a measure of adiposity, in the first 6 months of life is associated with higher early childhood SBP, particularly in children who are thin at birth.
Division of Newborn Medicine, Children's Hospital Boston, Boston, MA 02115, USA. mandy.belfort@childrens.harvard.edu
Mandy B
MB
Belfort
Sheryl L
SL
Rifas-Shiman
Janet
J
Rich-Edwards
Ken P
KP
Kleinman
Matthew W
MW
Gillman
D001724:Birth Weight / Q000502:physiology*; D001794:Blood Pressure; D001827:Body Height; D015992:Body Mass Index; D002675:Child, Preschool; D015331:Cohort Studies; D006128:Growth / Q000502:physiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn / Q000254:growth & development*; D015430:Weight Gain / Q000502:physiology*