Evaluation of Plasma Amino Acid Levels in Preterm Infants and Their Potential Correlation with Retinopathy of Prematurity

Abstract

Aim. The aim of this study is to ascertain whether the level of circulating amino acids (aa) is associated with retinopathy of prematurity (ROP). Methods. This is a randomized controlled study of 55 infants born at gestational age (GA) ≤32 weeks or birth weight (BW) ≤1500 grams. Serum samples were obtained from two groups: Group A comprised of 26 preterm infants with ROP and Group B comprised of 29 preterm infants without ROP. Plasma aa levels were analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Correlation test and multivariate regression analysis were used to evaluate the relationship between plasma aa levels and variables. Results. The mean serum arginine and glutamine levels were significantly higher, but the mean lysine and aspartic acid levels were significantly lower in Group A, compared to Group B ( $p=0.04$ , $p=0.002$ , $p=0.029$ , and $p=0.002$ , respectively). In multivariate analysis, the mean arginine and lysine levels were significantly associated with the stage of the disease ( $p=0.03$ and $p=0.01$ , respectively). No significant differences were determined between the groups in terms of alanine, asparagine, valine, leucine, phenylalanine, tyrosine, serine, proline, citrulline, cysteine, ornithine, tryptophan, methionine, threonine, taurine, and isoleucine amino acids ( $p>0.05$ , respectively). Conclusions. These results indicate a significant association between high arginine and glutamine, with low lysine and aspartic acid serum concentrations with ROP. Due to higher serum concentrations in ROP, extra arginine-glutamine supplementation in hyperoxic conditions may be unfavorable through pathways involving reactive oxygen, particularly in patients with ROP.