Increased inflammatory markers in adolescents born extremely preterm and small for gestational age

Abstract

Low birth weight has been associated with chronic low-grade inflammation and later cardiovascular disease. Whether this is related to low birth weight due to premature birth, being born small for gestational age (birth weight below the 10 th per- centile for gestational age) or variations in postnatal growth patterns is unknown. The objective of this study was to explore the impact of fetal growth restriction versus low birth weight due to prematurity on inflammatory status in later life. We investigated systemic markers of cell-mediated immune activation, kynurenine/tryptophan ratio and high-sensitive CRP (hs-CRP), in two population-based cohorts of children aged 10 and 17 years, who were born preterm (gestational age ≤ 28 weeks) or with an extremely-low-birth weight (< 1000 g) (n = 4). The controls were sex-and age-matched term-born with appropriate for gesta- tional age birth weight children (n = 75). Children born premature and small for gestational age had higher Kyn/Trp and hs-CRP compared to both age-matched preterms with appropriate for gestational age birth weight (p = 0.01 and p = 0.002, for Kyn/Try ratio and CRP respectively) and controls (p < 0.001 and p = 0.001). No significant differences in inflammatory markers were observed between appropriate for gestational age preterms and controls. Our observations suggest that the chronic low-grade immune activation observed in adults born with a low birth weight may be related to fetal growth restriction rather than low birth weight due to prematurity.