模拟不同光疗强度对早产儿肠外营养液中丙二醛、维生素C及维生素E的影响

To simulate effects of different intensities of phototherapy on malondialdehyde,vitamin C and vitamin E levels in parenteral nutrition for premature infants

目的模拟不同光疗强度对早产儿肠外营养液中脂肪乳过氧化产物丙二醛、维生素C及维生素E含量的影响。方法在严格无菌条件下配制早产儿肠外营养液,模拟临床输液环境,设定4种不同强度光疗模式,分别为室内光组、单面光疗组、双面光疗组、三面光疗组,将各组根据是否遮光,再分为光暴露/光疗亚组和遮光亚组,测定每个亚组在光疗前及光疗6、12、18、24 h时肠外营养液中丙二醛、维生素C及维生素E的含量。每个亚组均配制10份肠外营养液,每个时间点抽取每份营养液的2 ml进行检测。采用重复测量方差分析,不符合Mauchly球形检验时,用Greenhouse-Geisser法进行校正。结果(1)随着光疗时间的延长,单面光疗组光暴露/光疗亚组及遮光亚组的丙二醛含量均增加[光疗前:(3.777±0.112)与(3.746±0.141)nmol/ml,光疗6 h:(3.808±0.122)与(3.715±0.145)nmol/ml,光疗12 h:(4.546±0.138)与(4.507±0.136)nmol/ml;光疗18 h:(6.116±0.151)与(5.239±0.156)nmol/ml;光疗24 h:(7.569±0.136)与(5.300±0.200)nmol/ml,P值均<0.05],但维生素C和维生素E含量均降低[①维生素C:光疗前:(62.507±0.205)与(62.341±0.144)μg/ml,光疗6 h:(51.211±0.086)与(58.128±0.076)μg/ml,光疗12 h:(43.288±0.084)与(55.351±0.050)μg/ml;光疗18 h:(35.758±0.113)与(51.215±0.093)μg/ml;光疗24 h:(33.473±0.075)与(48.473±0.080)μg/ml;②维生素E:光疗前:(4.101±0.132)与(4.084±0.141)μg/ml,光疗6 h:(3.761±0.119)与(3.904±0.075)μg/ml,光疗12 h:(3.654±0.092)与(3.729±0.087)μg/ml;光疗18 h:(3.385±0.102)与(3.582±0.119)μg/ml;光疗24 h:(3.313±0.127)与(3.438±0.113)μg/ml,P值均<0.05],室内光组、双面光疗及三面光疗组也是相同情况。不同光照强度中光暴露/光疗亚组不同时间点(光疗前除外)丙二醛含量均高于遮光组,但维生素C和维生素E含量均低于遮光组(P值均<0.001)。(2)对光暴露/光疗亚组分析显示,光疗强度越大,丙二醛含量越高,维生素C和维生素E含量越低,各组两两比较差异均有统计学意义(P值均<0.05);对遮光亚组分析显示,室内光与单面光的丙二醛含量比较差异无统计学意义(F=2.383,P=0.140),其余各组两两比较差异均有统计学意义(P值均<0.05);光疗强度越大,维生素C含量越低,各组之间比较差异均有统计学意义;除双面光与三面光的维生素E含量比较差异无统计学意义外(F=1.358,P=0.259),其余各组两两比较差异均有统计学意义(P值均<0.05)。结论光疗可使早产儿肠外营养液中丙二醛的含量升高,加重脂肪乳的过氧化程度;同时可以使其中维生素C、维生素E含量降低,降低营养液的抗氧化程度。

Objective To investigate the effects of different phototherapy intensities on the levels of malondialdehyde,a peroxidation product of intralipid,vitamin C and vitamin E in parenteral nutrition for premature infants.Methods The parenteral nutrition for premature infants was prepared under strict aseptic condition and was divided into four groups based on different phototherapy intensities in simulated clinical settings,which were indoor light group,single-,double-,and three-sided phototherapy group.According to whether the nutrient solution shielded for light or not,each group was further divided into two subgroups:exposure or non-exposure group.The levels of malondialdehyde,vitamin C and vitamin E in all groups before phototherapy and 6,12,18,and 24 h after phototherapy were measured.Ten samples of parenteral nutrient solutions were prepared for each group,of which 2 ml were extracted for test at different time points.Repeated measurement analysis of variance was used for data analysis and the results were adjusted using Greenhouse-Geisser method if failed in Mauchly sphere test.Results With the increase of phototherapy time,the malondialdehyde level increased in the exposure and the non-exposure subgroups in the one-sided phototherapy group[before phototherapy:(3.777±0.112)vs(3.746±0.141)nmol/ml;phototherapy for 6 h:(3.808±0.122)vs(3.715±0.145)nmol/ml;12 h:(4.546±0.138)vs(4.507±0.136)nmol/ml;18 h:(6.116±0.151)vs(5.239±0.156)nmol/ml;24 h:(7.569±0.136)vs(5.300±0.200)nmol/ml;all P<0.05],but the level of vitamin C[before phototherapy:(62.507±0.205)vs(62.341±0.144)μg/ml;phototherapy for 6 h:(51.211±0.086)vs(58.128±0.076)μg/ml;12 h:(43.288±0.084)vs(55.351±0.050)μg/ml;18 h:(35.758±0.113)vs(51.215±0.093)μg/ml;24 h:(33.473±0.075)vs(48.473±0.080)μg/ml]and vitamin E decreased[before phototherapy:(4.101±0.132)vs(4.084±0.141)μg/ml;phototherapy for 6 h:(3.761±0.119)vs(3.904±0.075)μg/ml;12 h:(3.654±0.092)vs(3.729±0.087)μg/ml;18 h:(3.385±0.102)vs(3.582±0.119)μg/ml;24 h:(3.313±0.127)vs(3.438±0.113)μg/ml,all P<0.05].The same situation was also observed in indoor light group,double-,and three-sided phototherapy groups.The malondialdehyde level at different time in the exposure subgroups were higher but the vitamin C and vitamin E levels were lower than those in the non-exposure subgroups,regardless of the phototherapy intensities(all P<0.001).(2)The analysis of all exposure phototherapy subgroups showed that the higher the intensity of light therapy,the higher the malondialdehyde level,and the lower the level of vitamin C and vitamin E,with statistical significance differences in any pairwise comparison.Analysis of all non-exposure subgroups showed statistically significant differences in the malondialdehyde level in any pairwise comparison(all P<0.05)except for the comparison between indoor light group and single-sided phototherapy group(F=2.383.P=0.140).Moreover,the greater the phototherapy intensities,the lower vitamin C level,with statistically significant differences in any pairwise comparison.And statistical significance differences were observed in the vitamin E level in any pairwise comparison(all P<0.05)except for the comparison between double-and three-sided phototherapy groups(F=1.358,P=0.259).Conclusions Phototherapy can increase the malondialdehyde level in parenteral nutrient solution for premature infants and the degree of intralipid peroxidation,but can also lead to vitamin C and vitamin E loss in the parenteral nutrient and weaken its antioxidant capacity.