Urinary Uric Acid/Creatinine Ratio as a Marker of Mortality and Unfavorable Outcome in NICU-Admitted Neonates

Shahin Nariman; Ziba Mosayebi; Setareh Sagheb; Hadith Rastad; Seyyed Saeed Hosseininodeh

doi:10.5812/ijp.5739

Urinary Uric Acid/Creatinine Ratio as a Marker of Mortality and Unfavorable Outcome in NICU-Admitted Neonates

Iran J Pediatr. 2016 Jun 1;26(4):e5739. doi: 10.5812/ijp.5739. eCollection 2016 Aug.

Authors

Shahin Nariman¹, Ziba Mosayebi², Setareh Sagheb¹, Hadith Rastad³, Seyyed Saeed Hosseininodeh⁴

Affiliations

¹ Department of Pediatrics, Tehran University of Medical Sciences, Tehran, IR Iran.
² Department of Pediatrics, Tehran University of Medical Sciences, Tehran, IR Iran; Children's Medical Center, Pediatric Center of Excellence, Tehran, IR Iran.
³ Research Development Center, Arash Hospital, Tehran University of Medical Sciences, Tehran, IR Iran.
⁴ Children's Medical Center, Pediatric Center of Excellence, Tehran, IR Iran.

Abstract

Background: The survival of neonates who have been admitted to the NICU, especially premature infants with few mortality and morbidity, is the most important attitude.

Objectives: We presumed whether urinary uric acid/creatinine (UUA/Cr) ratio can be a marker of mortality and adverse outcome in neonates which were admitted to the NICU.

Patients and methods: All preterm infants admitted to our NICU after birth from March 2014 to April 2015 were enrolled in this prospective cohort study. UUA/Cr was measured during the first day of life. The severity of diseases (indicated by the need for high set-up of mechanical ventilation, complications of prematurity, and duration of stay in the NICU) and neonatal death were considered to be the final unfavorable outcomes. The relationship between the Log-transformation (Ln) urinary uric acid/creatinine ratio and the Apgar score at the first and 5^th minute after birth and the duration of stay were analyzed by using linear regression. Statistical analysis was done by using STATA version 11 (STATA Corp, TX, USA). A P < 0.05 was considered to be statistically significant.

Results: A total of 362 preterm infants with a mean gestational age of 32.7 (± 3.9) weeks were admitted to the NICU, out of whom 64 (17.6%) had severe disease and 43 (11.8%) died. The mean UUA/Cr ratio was significantly higher in the admitted neonates (3.30 ± 1.95 vs. 1.36 ± 0.42. P = 0.0001). There was a negative correlation between the UUA/Cr ratio and the 1-minute Apgar score (r = -0.17, P = 0.006) and the 5-minute Apgar score (r = -0.19, P = 0.003). The 1-minute Apgar scores were negatively correlated with the outcome (OR = 0.68; P < 0.001) and the duration of stay (β = -.28; P < 0.001). There was no significant correlation between 5-minute Apgar scores and the outcome. There was a significant positive correlation between the UUA/Cr ratio and an unfavorable outcome (OR = 1.24; CI %95: 1.06 to 1.43, P = 0.006) and increasing duration of stay (β = 0.17; P = 0.009).

Conclusions: The urinary uric acid/creatinine ratio can be used as a simple, noninvasive parameter of the severity of disease and mortality in NICU-admitted neonates.

Keywords: Mortality; Newborn; Outcome; Urinary Uric Acid to Creatinine Ratio.