Growth and growth factors in premature infants receiving dexamethasone for bronchopulmonary dysplasia

Physical growth and the serum growth factors, insulin growth factor 1 (IGF1) and its binding protein (IGFBP3) were measured weekly during dexamethasone treatment and for 3 weeks after stopping therapy in 10 ventilated babies [median (range) birth weight 860 g (640-1210); median (range) gestational age 26 weeks (24-29)] with bronchopulmonary dysplasia (BPD). The mean (+/-SE) rates of change of all physical measures except crown-rump length (CRL) increased significantly after stopping dexamethasone: weight gain 13.2 (+/-1.5) on versus 30.0 (+/-1.9) g/day off treatment; occipital-frontal circumference 0.7 (+/-0.1) versus 1.0 (+/-0.1) cm/week; total body length (TBL) 0.7 (+/-0.1) versus 1.1 (+/-0.1) cm/week; CRL 0.5 (+/-0.1) versus 0.7 (+/-0.1) cm/week, and knee-ankle length (KAL) 0.13 (+/-0.02) versus 0.36 (+/-0.04) cm/week. Mean serum IGF-1 (1.57+/-0.13 versus 3.56+/-0.41 nmol/L) and IGFBP3 (0.94+/-0.03 versus 1.12 +/- 0.05 mg/L) levels also increased off treatment. The weekly dose of dexamethasone (mg/kg) was significantly negatively correlated with all physical growth measures (P<0.01), but showed no correlation with growth factors. Protein intake (g/kg/day) was significantly correlated (P<0.01) with weight gain (r = 0.28), changes in TBL (r = 0.32), serum IGF1 levels (r = 0.60), and IGFBP3 levels (r = 0.37). All aspects of physical growth are compromised during dexamethasone treatment for BPD. Poor growth during steroid treatment is associated with lower IGF1 and ICFBP3 levels. Further study is needed to examine the effect of varying dexamethasone dosage regimes and nutritional intake on the growth process in BPD.