(1) Association Between Postnatal Systemic Steroid Exposure and Growth and Body Composition near Hospital Discharge in Very Preterm Infants

Background: Postnatal systemic glucocorticoids (GC) are used to prevent bronchopulmonary dysplasia (BPD) but have been associated with adverse growth as measured by standard anthropometrics. Current evidence on the relationship between GC and body composition is limited. We hypothesized that postnatal GC exposure would be associated with suboptimal growth and increased adiposity for very preterm infants compared to those unexposed near time of hospital discharge.

Objectives: To evaluate the relationship between systemic postnatal GC use, growth, and body composition in preterm infants near time of hospital discharge.

Design/Methods: Preterm infants < 31 weeks’ gestation at birth (n=18) were enrolled in a prospective observational study of continuous glucose monitoring. GC (methylprednisolone, dexamethasone, and hydrocortisone) use was collected through retrospective chart review as a categorical variable (yes/no received GC) and a continuous variable (mg/kg dexamethasone equivalent). Outcome variables included growth (weight, length, and occipital frontal circumference (OFC) z-scores) and body composition (fat-free mass and % body fat) measured via air displacement plethysmography between 35 weeks PMA and hospital discharge. Group differences were assessed by independent t-tests. Linear regression analyses were used to evaluate associations between continuous steroid exposure and infant outcomes, with p< 0.05 considered significant.

Results: Cohort characteristics are detailed in Table 1. N=7 (40%) of infants were exposed to GC and had lower birth weight and gestational age compared to the GC naïve infants. The average postnatal GC exposure was 2.84 +/- 1.26 mg/kg dexamethasone equivalents. GC exposed infants had smaller length (t(16) = 4.63, p<.001) and OFC (t(16) = 2.71, p=0.02) z-scores prior to discharge compared to GC naïve infants (Table 2). Cumulative GC dosing had a negative association with OFC z-score prior to discharge (estimate(SE) of -0.49(0.19); p-value=0.02) and a positive association with % body fat z-score prior to discharge (estimate(SE) of 0.55(0.26); p-value=0.05) (Table 3). No other significant differences in growth or body composition were observed.

Conclusions: In this preliminary analysis, preterm infants treated with systemic GC differed in body composition and anthropometric measures compared to preterm infants not treated with systemic GC. Further research with a larger sample size is needed to confirm these findings.