Premature small for gestational age infants fed an exclusive human milk-based diet achieve catch-up growth without metabolic consequences at 2 years of age

Objective To compare postdischarge growth, adiposity and metabolic outcomes of appropriate for gestational age (AGA) versus small for gestational age (SGA) premature infants fed an exclusive human milk (HM)based diet in the neonatal intensive care unit. Design Premature infants (birth weight <= 1250 g) fed an exclusive HM-based diet were examined at 12-15 months corrected gestational age (CGA) (visit 1) for anthropometrics, serum glucose and non-fasting insulin, and at 18-22 months CGA (visit 2) for body composition by dual-energy X-ray absorptiometry. Results Of 51 children, 33 were AGA and 18 were SGA at birth. The SGA group had weight gain (g/day) equal to AGA group during the follow-up period. SGA had a significantly greater body mass index (BMI) z-score gain from visit 1 to visit 2 (0.25 +/- 1.10 vs -0.21 +/- 0.84, p= 0.02) reflecting catch-up growth. There were no significant differences in total fat mass (FM) and trunk FM between groups. SGA had significantly lower insulin level (5.0 +/- 3.7 vs 17.3 +/- 15.1 mu U/mL, p= 0.02) and homeostatic model of assessment-insulin resistance (1.1 +/- 0.9 vs 4.3 +/- 4.1, p= 0.02). Although regional trunk FM correlated with insulin levels in SGA (r= 0.893, p= 0.04), they had lower insulin level compared with AGA and no difference in adiposity. Conclusions SGA premature infants who received an exclusive HM-based diet exhibited greater catch-up growth without increased adiposity or elevated insulin resistance compared with AGA at 2 years of age. An exclusive HM-based diet may improve long-term body composition and metabolic outcomes of premature infants with <= 1250 g birth weight, specifically SGA.