Influence of Postconceptional Age on the Renal Biomarkers in Very-Low-Birth-Weight Infants

ABSTRACT

Purpose@#We investigated whether consecutive levels of new emerging renal biomarkers, including serum cystatin C (CysC) and urinary neutrophil gelatinase-associated lipocalin (NGAL)/creatinine (Cr) ratio, were affected by postconceptional age in very-low-birth-weight (VLBW) infants. @*Methods@#Repeatedly measured samples for each infant were divided into four groups according to postnatal age at birth (stage I), 3 to 7 days postnatally (stage II), 8 to 28 days postnatally (stage III), and >28 days postnatally (stage IV). The association between renal biomarkers and postconceptional age was assessed using Pearson’s correlation coefficient, and the mean values of renal biomarkers in the four stages were compared using repeated-measures analysis of variance. @*Results@#For samples measured at birth, serum CysC (r=–0.358, P=0.032) and urinary NGAL/Cr ratio (r=–0.522, P=0.001) were negatively correlated with gestational age, whereas serum Cr (r=0.148, P=0.390) was not. In addition, for all samples measured, serum CysC (r=–0.209, P=0.012), urinary NGAL/Cr ratio (r=–0.536, P28 days postnatally seems to be more affected by postconceptional age than serum CysC in VLBW infants.