Urinary Uric Acid/Creatinine Ratio as a Marker of Mortality and Unfavorable Outcome in NICU-Admitted Neonates|
Nariman, Shahin; Mosayebi, Ziba; Sagheb, Setareh; Rastad, Hadith & Hosseininodeh, Seyyed Saeed
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 setup
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 5th 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.
Urinary Uric Acid to Creatinine Ratio; Mortality; Newborn; Outcome