Abstract
Abstract: :
Purpose: We have previously shown in IGF-1 -/- mice that IGF-1 is critical to normal retinal vessel growth. Phase I of ROP is associated with retarded retinal vessel growth. The aim of this study was to examine the association between serum IGF-I and ROP and other complications of prematurity in premature infants. Methods: We conducted a prospective longitudinal study measuring serum IGF-I levels weekly in 48 premature infants from birth (post-menstrual age 24 to 32 weeks) until discharge from the hospital. Babies were evaluated for ROP and other morbidity:bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) and necrotizing enterocolitis (NEC). Results: Seventeen of 48 infants had ROP Stage 2-3 and of these, 13 had other morbidities (IVH, BPD or NEC) associated with preterm birth. Only 2 infants had postnatal morbidity (IVH) without also having ROP. Twenty-nine infants had minimal or no ROP (Stage 0-1) and no other morbidity. The relative risk for ROP Stage 2-3 and other morbidity was increased 5.7-fold (95% confidence interval 2.2-14.6) if IGF-I was less than 30 mg/L at 33 weeks post-menstrual age. After adjustment for post-menstrual age, each increase of 5 mg/L mean IGF-I during post-menstrual age 31-35 weeks decreased the risk of ROP Stage 2-3 by 59%. The median level of IGF-I at 31-35 weeks of gestation was 26 mg/L (range 17-49) for infants with ROP Stage 2-3 and other morbidity (n=19), compared to 38 mg/L (range 20-59) in the group with minimal or no ROP (Stage 0-1) and no other postnatal morbidity (n=29), p<0.0001. Conclusion: Persistent low serum levels of IGF-I after premature birth are associated with ROP (stages 2-3) and other complications of prematurity. Replacement of IGF-1 to in utero levels may prevent ROP and other complications of prematurity.
Keywords: 572 retinopathy of prematurity • 355 clinical (human) or epidemiologic studies: risk factor assessment • 423 growth factors/growth factor receptors