Effect of taurine supplementation on growth and development in preterm or low birth weight infants

BACKGROUND: Taurine is the most abundant free amino acid in breast milk. Evidence exists that taurine has important roles in intestinal fat absorption, hepatic function, and auditory and visual development in preterm or low birth weight infants. Observational data suggest that relative taurine deficiency during the neonatal period is associated with adverse long-term neurodevelopmental outcomes in preterm infants. Current standard practice is to supplement formula milk and parenteral nutrition solutions with taurine. OBJECTIVES: To assess the effect of providing supplemental taurine for enterally or parenterally fed preterm or low birth weight infants on growth and development. SEARCH STRATEGY: The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2007), MEDLINE (1966 - June 2007), EMBASE (1980 - June 2007), conference proceedings, and previous reviews. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared taurine supplementation versus no supplementation in preterm or low birth weight newborn infants. DATA COLLECTION AND ANALYSIS: Data were extracted using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors, and synthesis of data using relative risk, risk difference and weighted mean difference. MAIN RESULTS: Nine small trials were identified. In total, 189 infants participated. Most participants were greater than 30 weeks gestational age at birth and were clinically stable. In eight of the studies, taurine was given enterally with formula milk. Only one small trial assessed parenteral taurine supplementation. Taurine supplementation increased intestinal fat absorption [weighted mean difference 4.0 (95% confidence interval 1.4, 6.6) percent of intake]. However, meta-analyses did not reveal any statistically significant effects on growth parameters assessed during the neonatal period or until three to four months chronological age [rate of weight gain: weighted mean difference -0.25 (95% confidence interval -1.16, 0.66) grams/kilogram/day; change in length: weighted mean difference 0.37 (95% confidence interval -0.23, 0.98) millimetres/week; change in head circumference: weighted mean difference 0.15 (95% confidence interval -0.19, 0.50) millimeters/week]. There are very limited data on the effect on neonatal mortality or morbidities, and no data on long-term growth or neurological outcomes. AUTHORS' CONCLUSIONS: Despite that lack of evidence of benefit from randomised controlled trials, it is likely that taurine will continue to be added to formula milks and parenteral nutrition solutions used for feeding preterm and low birth weight infants given the putative association of taurine deficiency with various adverse outcomes. Further randomised controlled trials of taurine supplementation versus no supplementation in preterm or low birth weight infants are unlikely to be viewed as a research priority, but there may be issues related to dose or duration of supplementation in specific subgroups of infants that merit further research.