Pande Sumati, Brion Luc P, Campbell Deborah E, Gayle Yvonne, Esteban-Cruciani Nora V
Department of Pediatrics, Albert Einstein College of Medicine, Children's Hospital at Montefiore, Bronx, NY 10461, USA.
J Perinatol. 2005 Jul;25(7):470-7. doi: 10.1038/sj.jp.7211334.
Carnitine transfer across the placenta occurs predominantly during the third trimester. Unless L-carnitine is provided, very preterm infants develop carnitine deficiency. Although breast milk and infant formulas contain L-carnitine, parenteral nutrition solutions do not routinely provide L-carnitine. We hypothesized that prolonged L-carnitine supplementation in very preterm infants would improve weight gain and shorten length of stay in the hospital.
The study was a double-blind parallel placebo-controlled randomized clinical trial. Eligible patients were <29 weeks of gestation, <72 hours of age, and did not have a potentially life-threatening congenital malformation or hereditary metabolic disorder. Patients were stratified by gestational age (23 to 25(6/7) and 26 to 28(6/7) weeks), and randomized to receive, either L-carnitine at a dose of 50 mumol/kg/day, or placebo. Carnitine was provided intravenously until the infants tolerated 16 ml/day of feeds. The sample size was calculated to have 80% power to detect a 10% increase in weight gain from birth until 36 weeks of postmenstrual age or discharge from the hospital. Secondary outcome variables included food efficiency (defined as weight gain divided by caloric intake), weight gain at 4 weeks of age, time to regain birth weight and length of stay.
Among the 63 infants enrolled in the trial, 32 were randomized to L-carnitine and 31 to placebo. L-Carnitine supplementation did not significantly affect average daily weight gain from birth until 36 weeks or hospital discharge, or any of the secondary outcome variables.
Prolonged supplementation of L-carnitine did not improve long-term weight gain in very preterm infants.
肉碱跨胎盘转运主要发生在妊娠晚期。除非补充左旋肉碱，极早产儿会出现肉碱缺乏。尽管母乳和婴儿配方奶粉中含有左旋肉碱，但肠外营养溶液通常不提供左旋肉碱。我们推测，对极早产儿长期补充左旋肉碱会改善体重增加并缩短住院时间。
该研究是一项双盲平行安慰剂对照随机临床试验。符合条件的患者为妊娠<29周、年龄<72小时，且没有潜在危及生命的先天性畸形或遗传性代谢紊乱。患者按胎龄（23至25（6/7）周和26至28（6/7）周）分层，随机接受50 μmol/kg/天剂量的左旋肉碱或安慰剂。静脉给予肉碱，直至婴儿耐受每天16毫升的喂养量。计算样本量，以80%的检验效能检测从出生到月经后36周或出院时体重增加10%的情况。次要结局变量包括食物效率（定义为体重增加除以热量摄入）、4周龄时的体重增加、恢复出生体重的时间和住院时间。
在纳入试验的63名婴儿中，32名被随机分配到左旋肉碱组，31名被分配到安慰剂组。补充左旋肉碱对从出生到36周或出院时的平均每日体重增加以及任何次要结局变量均无显著影响。
对极早产儿长期补充左旋肉碱并不能改善其长期体重增加。
