The relationship between cord blood adipocytokine levels and retinopathy of prematurity

Abstract

Purpose: Data suggest that leptin and adiponectin are synthesized in utero and that the circulating fetal leptin and adiponectin concentration relates to the intrauterine growth pattern. As we have found that intrauterine growth retardation is related to an increased risk for retinopathy of prematurity (ROP) we investigated the levels of adipocytokines leptin and adiponectin in cord blood, and later development of ROP in very preterm newborn infants.

Methods: Twelve premature infants who did develop ROP (treated infants, n=5) were compared with 22 control infants whom did not develop ROP. These infants had a mean (SD) gestational age (GA) of 25.8 (1.9) weeks and birth weight (BW) of 829 (263) grams. Samples were obtained from umbilical cord blood at birth. The concentration of adiponectin and leptin was measured using ELISA (Mediagnost, Germany). Data on GA, BW, and ROP were also collected. The leptin and adiponectin levels obtained were compared using scatterplot analysis to determine cut-off levels to be used as a combined adipocytokine risk score where 1=adipocytokines levels indicate high risk of Type 1 ROP; 0=adipocytokines levels indicate low risk of Type 1 ROP. (Retinopathy of prematurity type 1: • ROP of any stage is present in zone I with plus disease; • ROP stage 3 is present in zone I without plus disease; • ROP stage 2 or 3 is present in zone II with plus disease).

Results: No significant differences in the cord blood levels of either leptin or adiponectin were detected between infants with no ROP development and infants with later ROP or between infants with no ROP and later TYPE 1 ROP. However undetectable leptin levels in combination with low adiponectin; i.e. below 2 µg/ml in cord blood was seen in all infants with type 1 ROP. Using these cut-offs as a combined risk score variable and hence utilizing both leptin and adiponectin cord blood levels simultaneously correctly identified all infants with type 1 ROP as high risk and 78% of the infants without Type 1 ROP as low risk.

Conclusions: These preliminary data suggest that determination of adipocytokine levels in combination in cord blood may be of value for an early indication of infants at risk of Type 1 ROP. We postulate that the limited quantity of adipose tissue at this stage of development might explain this observation. Our findings stress the importance of the prenatal milieu for postnatal retinal angiogenic development in preterm infants.