Effects of protein intake on IGF1 and ROP.

BackgroundInsulin-like growth factor 1 has been implicated in neural and retinal cell maturation. Optimizing insulin-like growth factor 1 may prevent morbidities, like retinopathy of prematurity. Our objective was to determine the effects of higher protein in parenteral nutrition for very low birth weight infants on insulin-like growth factor 1 and retinopathy of prematurity.MethodsThis was a post-hoc analysis of a prospective, double blind, randomized control trial of appropriate for gestational age, preterm infants (<1250 grams) randomized to high protein (N = 53) or conventional protein (N = 47) in early parenteral nutrition. Goal protein intake was 4 g/kg/d for high protein group and 3 g/kg/d for conventional protein group. Weekly insulin-like growth factor 1 and standard retinal examinations were evaluated.ResultsInsulin-like growth factor 1 was significantly associated with protein intake group controlling for postnatal age, gestational age and sex. Insulin-like growth factor 1 increased by 21.9% (p = 0.03) in the high protein group. Any retinopathy of prematurity or severe retinopathy of prematurity (grade ≥3 and/or plus disease) was not associated with group, actual daily protein intake or insulin-like growth factor 1. However, high protein group was associated with lower risk of plus disease (OR 0.17, p = 0.02). Infants with plus disease had 25% lower mean insulin-like growth factor 1 (p = 0.052).ConclusionHigher protein in parenteral nutrition was associated with increased insulin-like growth factor 1 and lower risk of plus disease in very low birth weight infants.