Impact of optimized amino acid and lipid emulsion regimens on protein synthesis and growth in preterm infants
Qu Ling
Wang Mokui
Abstract：Objective To investigate the effects of different amino acid to fat emulsion ratios in early stage on protein synthe-sis efficiency,growth,metabolic function,inflammatory response,and clinical outcomes of the preterm infants.Methods This prospective randomized controlled trial included 132 preterm infants(gestational age<37 weeks,birth weight<2 500 g)who were admitted to the neonatal intensive care unit of the First People's Hospital of Yibin,from October 2022 to October 2024.Infants were randomly assigned in a 1:1:1 ratio using a random number table and divided into three groups based on the amino acid to fat emulsion ratios in parenteral nutrition:the balanced group(3:3),the high amino acid low fat group(4:2),and the low amino acid high fat group(2:4).The total energy target was 110-120 kcal·kg-1·d-1.Observational indicators encompassed several categories:protein synthesis efficiency,including serum albumin,prealbumin and blood urea nitrogen;growth and development,measured by weight gain veloc-ity,length gain velocity,head circumference gain velocity,and extrauterine growth restriction(EUGR)incidence;hepatic and biliary function,assessed through ALT,AST,total bilirubin,direct bilirubin,and total bile acids;renal function,indicated by serum creatinine and cystatin-C;inflammation,monitored by C-reactive protein(CRP)and procalcitonin(PCT);and clinical outcomes,such as the time to full enteral feeding and the length of hospital stay.Results On day 7 of the intervention,the high amino acid low fat group had higher serum albumin levels in the high amino acid low fact group than in the balanced group and the low amino acid high fat group((30.94±2.32)g·L-1,(29.61±2.12)g·L-1,(29.21±2.22)g·L-1,respectively;F=7.289,P<0.05),and higher prealbumin levels in the high amino acid low fact group than in the balanced group and the low amino acid high fat group((185.55±19.88)mg·L-1,(175.31±18.20)mg·L-1,(172.16±21.51)mg·L-1,respectively;F=5.444,P<0.05).Blood urea nitrogen levels showed no significant differences among the three groups(F=0.484,P>0.05).The high amino acid low fat group exhibited a higher weight gain rate than the balanced group and the low amino acid high fat group((20.50±2.10)g·kg-1·d-1,(18.30±2.00)g·kg-1·d-1,(17.60±1.60)g·kg-1·d-1,respectively;F=27.360,P<0.05),and a lower incidence of extrauterine growth restriction than the balanced group and the low amino acid high fat group(χ2=6.114,P<0.05).Length and head circumference growth rates showed no significant differences among the three groups(F=1.984,P>0.05;F=2.768,P>0.05).The high amino acid low fat group had lower incidences of hyperglycemia and hyperlipidemia than the balanced group and the low amino acid high fat group(χ2=7.247,P<0.05;χ2=6.417,P<0.05),and there was no significant difference in the incidence of cholestasis among the three groups(χ2=0.451,P>0.05).The low amino acid high fat group had higher ALT levels than the balanced group and the high amino acid low fat group((30.07±6.23)U·L-1,(27.20±4.97)U·L-1,(27.66±4.91)U·L-1,respectively;F=3.586,P<0.05).Total bilirubin and total bile acid levels were higher in the low amino acid high fat group than in the high amino acid low fat group(total bilirubin:(9.20±1.49)μmol·L-1 vs(8.32±1.55)μmol·L-1,F=3.903,P<0.05;total bile acid:(13.69±2.13)μmol·L-1 vs(12.30±2.05)μmol·L-1,F=4.784,P<0.05),but there was no significant difference between the two groups and the balanced group(P>0.05),and there was no significant difference between the balanced group and the high amino acid low fat group(P>0.05).There were no significant differences in the direct bilirubin,serum creatinine and cystatin-C levels among the three groups(F=0.124,P>0.05;F=0.234,P>0.05;F=0.564,P>0.05).The high amino acid low fat group had lower C-reactive protein levels than the balanced group and the low amino acid high fat group((1.69±0.38)mg·L-1,(2.09±0.36)mg·L-1,(2.13±0.49)mg·L-1,respec-tively;F=15.120,P<0.05),and lower procalcitonin levels in the high amino acid low fact group than in the balanced group and the low amino acid high fat group((0.30±0.10)μg·L-1,(0.37±0.12)μg·L-1,(0.45±0.11)μg·L-1,respectively;F=19.170,P<0.05).The high ami-no acid low fat group achieved full enteral feeding sooner than the balanced group and the low amino acid high fat group((15.7±3.0)d,(18.5±3.3)d,(19.2±3.4)d,respectively;F=14.143,P<0.05)and had a shorter hospital stay in the high amino acid low group than in the balanced group and the low amino acid high fat group((31.6±7.6)d,(35.2±7.1)d,(36.8±8.5)d,respectively;F=5.248,P<0.05).Conclusion Early parenteral nutrition with 4 g·kg-1·d-1 amino acids and 2 g·kg-1·d-1 fat emulsion enhances protein synthesis efficien-cy,weight gain rate,reduces inflammation and metabolic complications,and shortens time to full enteral feeding and hospital stay.
Keywords：Preterm infantAmino acidsFat emulsionProtein synthesisParenteral nutrition
Publication Date：2025-08-25
Online Publishing Date：2025-09-01(First online date of this platform, not the publication date of the document)
Pages：6( 947-952 )