Physical growth and retinopathy in preterm infants: Involvement of IGF-I and GH

GH and IGF-I are important for physical growth. We measured serum levels of these factors in preterm infants. The study population (n = 81) was divide d into three groups according to the gestational age. We evaluated differen ces in serum GH and IGF-I levels among groups with regard to physical growt h and development of retinopathy of prematurity. Serum GH levels in extreme ly preterm infants born at < 28 wk of gestational age were significantly hi gher than levels in those born between 28 and 34 wk at 1 and 2 mo of age. I n contrast, serum IGF-I levels in extremely preterm infants remained low, w hereas those in the other two groups gradually increased. Evaluation of the effects of GH and IGF-I on physical growth in very low birth weight infant s (< 1500 g) showed that IGF-I concentrations were positively related to ph ysical growth for several months after birth, whereas no relationship was o bserved between GH and physical growth. Multivariate analysis demonstrated that high GH concentration at 1 mo of age was significantly associated with development of severe retinopathy of prematurity. In conclusion, persisten t low serum IGF-I levels may explain the slow physical growth during neonat al life, and exposure of high GH may cause, at least in part, severe retino pathy of prematurity in preterm infants.