Neonatal IGF-1/IGFBP-1 axis and retinopathy of prematurity are associated with increased blood pressure in preterm children

Abstract

Aim: Preterm children are at risk of developing increased blood pressure (BP). We evaluated possible associations between BP, early insulin-like growth factor-1 (IGF-1) and IGF-binding protein-1 (IGFBP-1) levels and retinopathy of prematurity (ROP) in preterm children.

Methods: The study included 32 infants: median gestational age 28.1 weeks (range 24.6-31.3) and birthweight standard deviation scores (SDS) (±SD) 1.0 ± 2.7. IGF-1 and IGFBP-1 at postnatal weeks 32.6-34.6 and ROP stages were established after birth. BP was measured at the age of 4 years. The ratio (IGF-1)(2)/IGFBP-1 was created to investigate the influence of both IGF-1 and IGFBP-1 to later BP.

Results: Diastolic BP correlated with IGFBP-1, inversely correlated with IGF-1 and IGF-1(2)/IGFBP-1 (r = -0.71, p < 0.0001) and positively correlated with catch-up growth velocity from lowest weight SDS to age 36.5 weeks (r = 0.48, p < 0.01), independent of gestational age. Children with moderate-to-severe ROP as neonates had higher mean arterial BP [78 (±95%CI 74-83) vs 71 (±95%CI 68-75) mm Hg, p < 0.05] adjusted for gestational age and birthweight SDS compared to children diagnosed with no to mild ROP.

Conclusion: Low neonatal IGF-1(2)/IGFBP-1 and severe ROP were associated with higher BP in 4-year-old children born very preterm and may thus predict future cardiovascular morbidity.

Keywords: Catch-up growth; Diastolic blood pressure; IGF-1; IGFBP-1; Preterm children; Retinopathy of prematurity.