Effect of sustained systemic inflammatory response on body composition in very premature infants

Abstract

Background: Infants experiencing catch-up growth devote a greater proportion of their energy to fat deposition at the expense of gains in lean mass. 

Objective: To determine the effect of the sustained systemic inflammatory response (SSIR) on fat mass (FM) in very preterm infants (VPI) at term corrected age (TCE). 

Methods: Prospective cohort study. Infants ≤ 31 weeks of gestational age (GA) were included. Multiple pregnancies, IUGR, SGA, congenital malformations, genetic syndromes and congenital infections were excluded. Procalcitonin (PCT) samples were collected at birth, 1st, 2nd and 4th week. Anthropometric, nutritional, maternal and neonatal data were collected. Body composition was measured by dual X-ray absorptiometry. Main exposure: RISS (PCT ≥ 50th percentile). Main result: %FM. The analysis was completed using generalized linear models adjusted for covariates. A level of significance p < 0.05 was adopted. 

Results: 23 VPI were studied sequentially, 11 (47.8%) with SSIR and 12 (52.2%) without SSIR. Birth weight 1204 (232) g. GA 29 (24- 31) weeks. No significant differences were observed in baseline anthropometric, nutritional, neonatal and maternal characteristics. In anthropometric, nutritional and neonatal characteristics at TCE, the SSIR group presented a significantly higher frequency of invasive ventilation, BPD, NEC, sepsis and stunting. In the GLM adjusted for significant covariates, it was found that the group with SSIR presented a significant increase in %FM (46.5% vs 30.7%, β 48.8 CI95% 6.8-78.7; p 0.03) compared to the group without RISS. Covariates did not influence significantly. 

Conclusions: Higher adiposity was observed in the VPI at TCE. The continuing influence of early diseases and SSIR on growth suggests that non-nutritional factors may also affect body composition trajectories.