Iron supplements may reduce SBP in LBW children at 7 years
Iron supplementation (1 or 2 mg Fe · kg−1· d−1) in low birth weight (LBW) children during infancy is associated with lower systolic blood pressure (SBP) at 7 years, a recent study has found.
To examine the effect of iron supplementation given to LBW infants on midchildhood BP, researchers conducted a randomized, double-blind, controlled trial including 285 marginally LBW (2,000 to 2,500 g) infants at two Swedish centres between May 2004 and November 2007.
Participants were randomly assigned to receive either placebo or 1 or 2 mg Fe · kg−1 · d−1 from 6 weeks to 6 months of age. Researchers then compared SBP, diastolic (D)BP and the prevalence of children with BP within the hypertensive range (>90th percentile) between the groups in secondary analyses at the age of 7 years.
Intention-to-treat analysis of BP was performed in 189 children (66 percent).
LBW children who received placebo (n=70), 1 mg Fe · kg−1 · d−1 (n=54) or 2 mg Fe · kg−1 · d−1 (n=65) had mean SBP of 103±8.1, 101±7.5 and 101±7.8 mm Hg, respectively. Combining the iron-supplemented group in covariate-adjusted analyses showed that children who received iron supplementation in infancy had a mean SBP of 2.2 mm Hg (95 percent CI, 0.3 to 4.2 mm Hg) lower than in those who did not receive supplementation (p=0.026).
Based on multivariate logistic regression analysis, the odds of having an SBP within the hypertensive range at the age of 7 years were reduced with iron supplementation in infancy (odds ratio, 0.32; 0.11 to 0.96). No significant differences in DBP were observed between the intervention groups.
“This novel observation [to our knowledge] suggests that the increased risk of hypertension that is observed in children and adults who are born small might be reduced with early micronutrient interventions,” researchers said.