Growth and Hormones Changes during the First Two Years in Very Low Birth Weight Infants

Kwon, Oh Kun; Lee, Jun Sook; Sung, Tae Jung; Yang, Seung; Park, Mi Jung; Hwang, Il Tae

Abstract

PURPOSE
This study aims to investigate postnatal growth and examine the longitudinal change of leptin, insulin, insulin-like growth factor-I (IGF-I), adiponectin, and ghrelin in very low birth weight (VLBW) infants.
METHODS
Weight, height, and head circumference (HC) were prospectively measured at birth, full term, and at 2, 4, 6, 12 and 24 months of corrected age (CA) in 91 VLBW infants (41 females and 50 males). They were evaluated as either being small for gestational age (SGA) or appropriate for gestational age (AGA). Blood samples were serially taken for IGF-I, insulin, leptin, adiponectin, and ghrelin.
RESULTS
1) Weight, height, and HC Z scores decreased from birth to 2 months of CA at a deeper rate for AGA and birth weight < 1,000 g than for SGA and < 1,000 g birth weight < 1,500 g infants. 2) Weight, height, and HC Z scores increased from 2 months to 24 months of CA for the whole population. 3) 25.0% in the SGA and 5.4% in the AGA group did not show weight catch up growth (< -2 SDS) at 1 year of age (P < 0.05). 4) At 12 months of CA, 16.7% in the SGA and 13% in the AGA group did not show height catch up growth. 5) Leptin, ghrelin, IGF-I concentrations increased during the first 2 years of life in VLBW. 6) 1 year weight Z score is related to term weight Z score (beta = 0.775, P = 0.001). One year height Z score is related to term weight Z score. (beta = 0.632, P = 0.000)
CONCLUSION
Rapid catch up growth occurred mainly during the first year of life, irrespective of SGA or AGA. Leptin, ghrelin, and IGF-I concentration increased during the first 2 years of life in VLBW. Rapid catch up growth is thus required to give rapid and enough nutrition after birth in VLBW.