OBJECTIVE: Our aim was to evaluate whether administration of additional cysteine is safe and stimulates glutathione synthesis in preterm infants in early life. METHODS: We conducted a prospective, randomized, clinical trial with infants with birth weights of <1500 g (N = 20). The infants were assigned randomly to receive either a standard dose (45 mg/kg per day) or a high dose (81 mg/kg per day) of cysteine. Intakes of other amino acids were similar, providing a total protein intake of 2.4 g/kg per day in both groups. We recorded base requirements in the first 6 days of life. On postnatal day 2, we conducted a stable isotope study to determine glutathione concentrations and synthesis rates in erythrocytes. RESULTS: Base requirements were higher in the high-dose cysteine group on days 3, 4, and 5. Despite an 80% increase in cysteine intake, plasma cystine concentrations did not increase. Glutathione concentrations and synthesis rates did not increase with additional cysteine administration. CONCLUSIONS: Administration of a high dose of cysteine (81 mg/kg per day) to preterm infants seems clinically safe but does not stimulate glutathione synthesis, compared with a lower dose (45 mg/kg per day). Further research is required to determine whether there is significant benefit associated with cysteine supplementation.
RCT Entities:
OBJECTIVE: Our aim was to evaluate whether administration of additional cysteine is safe and stimulates glutathione synthesis in preterm infants in early life. METHODS: We conducted a prospective, randomized, clinical trial with infants with birth weights of <1500 g (N = 20). The infants were assigned randomly to receive either a standard dose (45 mg/kg per day) or a high dose (81 mg/kg per day) of cysteine. Intakes of other amino acids were similar, providing a total protein intake of 2.4 g/kg per day in both groups. We recorded base requirements in the first 6 days of life. On postnatal day 2, we conducted a stable isotope study to determine glutathione concentrations and synthesis rates in erythrocytes. RESULTS: Base requirements were higher in the high-dose cysteine group on days 3, 4, and 5. Despite an 80% increase in cysteine intake, plasma cystine concentrations did not increase. Glutathione concentrations and synthesis rates did not increase with additional cysteine administration. CONCLUSIONS: Administration of a high dose of cysteine (81 mg/kg per day) to preterm infants seems clinically safe but does not stimulate glutathione synthesis, compared with a lower dose (45 mg/kg per day). Further research is required to determine whether there is significant benefit associated with cysteine supplementation.
Authors: Kara L Calkins; Lauren A Sanchez; Chi-Hong Tseng; Kym F Faull; Alexander J Yoon; Christopher M Ryan; Thuc Le; Stephen B Shew Journal: JPEN J Parenter Enteral Nutr Date: 2014-08-19 Impact factor: 4.016
Authors: Robert K Huston; J Mark Christensen; Sultan M Alshahrani; Sumeia M Mohamed; Sara M Clark; Jeffrey A Nason; Ying Xing Wu Journal: PLoS One Date: 2015-08-28 Impact factor: 3.240