Carnitine supplementation in premature neonates: Effect on plasma and red blood cell total carnitine concentrations, nutrition parameters and morbidity

Guidelines for parenteral nutrition in preterm infants: The American Society for Parenteral and Enteral Nutrition

BACKGROUND

Parenteral nutrition (PN) is prescribed for preterm infants until nutrition needs are met via the enteral route, but unanswered questions remain regarding PN best practices in this population.

METHODS

An interdisciplinary committee was assembled to answer 12 questions concerning the provision of PN to preterm infants. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) process was used. Questions addressed parenteral macronutrient doses, lipid injectable emulsion (ILE) composition, and clinically relevant outcomes, including PNALD, early childhood growth, and neurodevelopment. Preterm infants with congenital gastrointestinal disorders or infants already diagnosed with necrotizing enterocolitis or PN-associated liver disease (PNALD) at study entry were excluded.

RESULTS

The committee reviewed 2460 citations published between 2001 and 2023 and evaluated 57 clinical trials. For most questions, quality of evidence was very low. Most analyses yielded no significant differences between comparison groups. A multicomponent oil ILE was associated with a reduction in stage 3 or higher retinopathy of prematurity (ROP) compared to an ILE containing 100% soybean oil. For all other questions, expert opinion was provided.

CONCLUSION

Most clinical outcomes were not significantly different between comparison groups when evaluating timing of PN initiation, amino acid dose, and ILE composition. Future clinical trials should standardize outcome definitions to permit statistical conflation of data, thereby permitting more evidence based recommendations in future guidelines. This guideline has been approved by the ASPEN 2022-2023 Board of Directors.

Association between health literacy, depressive symptoms, and suicide-related outcomes in adolescents: A longitudinal study

BACKGROUND

Health literacy is associated with mental disorders in adolescents. This study aimed to examine the associations between health literacy, depressive symptoms, and suicide-related outcomes.

METHODS

In terms of participants, 937 middle school students in Shenyang City, China were enrolled between December 2018 and December 2019 to assess health literacy, depressive symptoms and suicide-related outcomes. Multiple logistic regression models were used to examine possible associations.

RESULTS

Adequate health literacy was negatively associated with 12-month follow-up depressive symptoms (RR = 0.115, 95 % CI: 0.032-0.411) and suicide-related outcomes (RR = 0.230, 95 % CI: 0.085-0.618) in females. Meanwhile, in females, interpersonal relationship, stress management, and self-actualization were negatively related to depressive symptoms, while physical activities, self-actualization, and health awareness are protective factors for suicide-related outcomes (P < 0.05 for each).

LIMITATIONS

Recall and reporting bias might be inevitable for self-reported data, and due to the small sample size, the predictive effect may not be very significant.

CONCLUSIONS

These findings suggest that adequate health literacy may serve as a critical and independent protective factor for poor long-term mental health outcomes and that the predictive effect is more pronounced in female students. Public health efforts to enhance health literacy levels are required to maintain and improve adolescents' mental health outcomes.

Parenteral Nutrition

Prematurity and other complications at birth are nutritional emergencies. Parenteral nutrition is a bridge to enteral nutrition for a few days or months, and sometimes the sole source of nutrition for life. Parenteral nutrition regimens are constructed to provide adequate and balanced energy, macronutrients, and micronutrients to support growth and prevent deficiencies. Neonatal parenteral nutrition regimens are complicated by periodic shortages of essential products, compatibility challenges, and contaminants. Newborns benefit from serial growth assessments, monitoring of biochemical status, nutrition-focused physical examinations, and management by a multidisciplinary team to ensure adequacy of parenteral nutrition and promote best outcomes.

Impact of Parenteral Lipid Emulsion Components on Cholestatic Liver Disease in Neonates

Total parenteral nutrition (TPN) is a life-saving intervention for infants that are unable to feed by mouth. Infants that remain on TPN for extended periods of time are at risk for the development of liver injury in the form of parenteral nutrition associated cholestasis (PNAC). Current research suggests the lipid component of TPN is a factor in the development of PNAC. Most notably, the fatty acid composition, vitamin E concentration, and presence of phytosterols are believed key mediators of lipid emulsion driven PNAC development. New emulsions comprised of fish oil and medium chain triglycerides show promise for reducing the incidence of PNAC in infants. In this review we will cover the current clinical studies on the benefit of fish oil and medium chain triglyceride containing lipid emulsions on the development of PNAC, the current constituents of lipid emulsions that may modulate the prevalence of PNAC, and potential new supplements to TPN to further reduce the incidence of PNAC.

Carnitine deficiency in preterm infants: A national survey of knowledge and practices

OBJECTIVE

Lipid supplementation improves developmental outcomes in preterm infants. Carnitine is essential for lipid metabolism; however, despite high risk for carnitine deficiency, there are no standards for carnitine supplementation in preterm infants receiving total parenteral nutrition (TPN). Our objective was to assess knowledge, beliefs and practices regarding preterm carnitine deficiency and supplementation among neonatal practitioners.

METHODS

Cross-sectional electronic survey administered via a nationally representative listserv of neonatal practitioners.

RESULTS

492 respondents participated in the survey. Only 21% of respondents were aware that carnitine is secreted by the placenta. 72% believed that carnitine deficiency was common, and 60% believed deficiency could have serious consequences. Five percent routinely screened for deficiency, and 40% routinely provided carnitine supplementation. Respondents with >5 years' experience were more likely to report using carnitine supplementation (50% vs. 38%).

CONCLUSIONS

Although most respondents believed that carnitine deficiency is common and could have serious consequences, few screened for deficiency and fewer than half routinely supplemented. Thus, many preterm infants remain at risk for carnitine deficiency. Further research is needed to elucidate the risks of carnitine deficiency in these vulnerable infants.

Intravenous Carnitine Administration in Addition to Parenteral Nutrition With Lipid Emulsion May Decrease the Inflammatory Reaction in Postoperative Surgical Patients

BACKGROUND

A prospective randomized study was performed to investigate the validity of intravenous carnitine administration during postoperative parenteral nutrition (PN) with lipid emulsion.

METHODS

Patients undergoing surgery for gastric or colorectal cancer were enrolled in the study and were randomly divided into two groups (n = 8 in each group): 1) group L, who received a peripheral PN (PPN) solution of 7.5% glucose, 30% amino acid, and 20% lipid emulsion; and 2) group LC, who received the same PPN solution, as well as carnitine intravenously. PPN was performed from postoperative day (POD) 1 to POD4. Clinical and laboratory parameters were compared between the two groups; statistical significance was set at P < 0.05.

RESULTS

Serum carnitine concentrations were significantly higher in group LC on POD3 (P < 0.01) and POD7 (P = 0.01). Postoperative changes in laboratory parameters and morbidity were comparable between the two groups. However, the decrease in C-reactive protein from POD3 to POD7 was significantly greater in group LC than in group L (P = 0.011).

CONCLUSION

The results show that intravenous carnitine administration in addition to PN is safe and may be beneficial for recovery from postoperative inflammatory reactions.

Impact of l-carnitine supplementation on metabolic profiles in premature infants

OBJECTIVE

To describe the influence that of l-carnitine supplementation on acylcarnitine (AC) profiles and hospital outcomes in premature infants.

STUDY DESIGN

This study is a secondary analysis of previously reported work. Metabolic profiles were obtained using standard newborn techniques on infants born between 23 and 31 completed weeks of gestation. The profiles were drawn within the first 24 h after birth and on approximately days 7, 28 and 42 of life, or at the time of discharge. A single, central, contract laboratory analyzed and managed the samples.

RESULTS

We studied 995 patients; none was subsequently diagnosed with an inborn error of metabolism. l-Carnitine was added to parenteral nutrition in 390 (39%) study subjects; 592 (60%) did not receive supplementation. Non-supplemented infants were more likely to develop low levels of free carnitine (FC; <7 μm) on day 28; (41% vs 5%, P<0.01); and FC values were lower on day 7. Despite higher levels of FC and fewer patients with significant carnitine deficiencies, we found no evidence that l-carnitine supplementation was associated with improved short-term hospital outcomes.

CONCLUSION

l-Carnitine supplementation is common in prematurely born neonates and is associated with higher carnitine levels, but is not associated with improved short-term hospital outcomes.

The Use of Carnitine in Pediatric Nutrition

Carnitine is synthesized endogenously from methionine and lysine in the liver and kidney and is available exogenously from a meat and dairy diet and from human milk and most enteral formulas. Parenteral nutrition (PN) does not contain carnitine unless it is extemporaneously added. The primary role of carnitine is to transport long-chain fatty acids across the mitochondrial membrane, where they undergo beta-oxidation to produce energy. Although the majority of patients are capable of endogenous synthesis of carnitine, certain pediatric populations, specifically neonates and infants, have decreased biosynthetic capacity and are at risk of developing carnitine deficiency, particularly when receiving PN. Studies have evaluated for several decades the effects of carnitine supplementation in pediatric patients receiving nutrition support. Early studies focused primarily on the effects of supplementation on markers of fatty acid metabolism and nutrition markers, including weight gain and nitrogen balance, whereas more recent studies have evaluated neonatal morbidity. This review describes the role of carnitine in metabolic processes, its biosynthesis, and carnitine deficiency syndromes, as well as reviews the literature on carnitine supplementation in pediatric nutrition.

Effects of L-carnitine supplementation on respiratory distress syndrome development and prognosis in premature infants: A single blind randomized controlled trial

The aim of the present study was to investigate the efficacy of L-carnitine therapy on the occurrence and prognosis of respiratory distress syndrome (RDS). A single blind, randomized controlled trial study was conducted on 130 infants with gestational ages of 28-36 weeks. Infants were assigned to experimental groups (groups 1 and 2) and control groups (groups 3 and 4). Groups 1 and 3 consisted of infants with RDS, and groups 2 and 4 groups were composed of infants without RDS. The experimental groups were treated with carnitine. No statistically significant differences in serum carnitine levels were detected between the study and the control groups on day 1 of treatment (P=0.06). However, on day 7 of treatment, serum carnitine levels in the experimental groups were significantly increased (P=0.02), as compared with the control groups. The surfactant requirement value, which is how many rounds of surfactant therapy were required, was 1.56±0.97 in group 1, and 2.12±0.99 in group 3 (P<0.001). The mean duration of mechanical ventilation required was 3.04±3.60 days in group 1, and 4.73±5.63 days in group 3 (P<0.001). The present results indicate that carnitine supplementation in premature infants with RDS may help to increase carnitine levels, thus decreasing the duration of mechanical ventilation and surfactant requirement.

Biotin and carnitine deficiency due to hypoallergenic formula nutrition in infants with milk allergy

Amino acid formulas and hydrolyzed formulas given to infants in Japan with milk allergies theoretically contain little, if any, biotin and carnitine. We assessed biotin and carnitine insufficiency in six infants with milk allergy who were fed amino acid formulas and/or hydrolyzed formulas, by measuring urine 3-hydroxyisovaleric acid (3-HIA) and serum free carnitine (C0), respectively. All patients presented with elevated urine 3-HIA and lowered serum C0 compared with post-menstrual age-matched infants who were fed breast milk or standard infant formulas. Supplementation with biotin and L-carnitine immediately improved the insufficiency. Care should be taken to avoid biotin and carnitine deficiency in allergic infants fed amino acid or hydrolyzed formulas.

Differences in circulating carnitine status of preterm infants fed fortified human milk or preterm infant formula

OBJECTIVE

The aim of the study was to compare plasma carnitine profiles in fortified human milk (HM)-fed preterm infants or formula-fed preterm infants.

METHODS

Plasma acylcarnitine concentrations were determined in 20 formula-fed and 18 HM-fed preterm infants (birth weights between 1000 and 2200 g) by isotope dilution ESI MS/MS technique on study days 0, 14, and 28.

RESULTS

Concentrations of free carnitine (FC) and different acylcarnitines did not change during the 4 weeks of the study in infants fed HM. In contrast, in infants fed formula FC increased markedly (day 0: 29.989 [16.646] μmol/L, median [interquartile range], day 14: 43.972 [8.455], P < 0.05) along with increases of short-chain esters (C2 day 0: 5.300 [3.272], day 14: 6.773 [2.127], P < 0.05; C3 day 0: 0.070 [0.059], day 14: 0.110 [0.069], P < 0.05). In contrast, some medium-chain (C8:1, C12) and long-chain esters (C14, C16) decreased significantly in infant formula by day 14, whereas FC and C2 and C3 esters increased further by day 28 (FC: 47.672 [14.753], C2: 7.430 [4.688], C3: 0.107 [0.047]).

CONCLUSIONS

The altered carnitine ester profile likely reflects active involvement of the carnitine molecule in the buffering, metabolism, and elimination of nonphysiological acyl moieties.

Nutritional practices in the neonatal intensive care unit: analysis of a 2006 neonatal nutrition survey

OBJECTIVE

The goal of this investigation was to determine how current parenteral nutrition and enteral nutrition practice intentions for preterm infants compare with published recommendations and previous feeding practices.

METHODS

A survey of feeding strategies for 3 preterm infant weight groups was sent to NICU directors, neonatal fellowship directors, neonatologists, neonatal nurse practitioners, and neonatal dieticians. A total of 775 surveys were distributed by both electronic and standard mail services.

RESULTS

There were 176 survey responses (23%). The majority of practitioners initiated parenteral nutrition for very preterm infants in the first day of life. Ninety-one percent of respondents increased protein delivery daily. Most respondents increased lipid delivery at a fixed rate, rather than on the basis of triglyceride levels. Insulin was used in 98% of units, but only 12% of the time as a nutritional adjuvant to increase weight gain. Across all birth weight categories, breast milk was prescribed most commonly for the first enteral feeding. Enteral feedings were started earlier and increased faster than in the past, especially for extremely low birth weight infants (<1000 g). The majority of respondents prescribed enteral feedings for infants with indwelling umbilical arterial (75%) and umbilical venous (93%) catheters. Despite data that more rapid feeding advancement is safe, >80% of respondents increased feedings at rates of 10 to 20 mL/kg per day across all weight categories.

CONCLUSIONS

Clinicians reported that they are initiating parenteral and enteral nutrition earlier and in larger volumes than in the past, reflecting increased knowledge about best nutritional practices in very preterm neonates. The data suggest that the persistent extrauterine growth failure of preterm infants is not attributable to a lack of best nutritional practice knowledge and intention.

Carnitine supplementation for preterm infants with recurrent apnea

BACKGROUND

Apnea of prematurity is a common problem in preterm infants in the neonatal intensive care setting (NICU), often delaying their discharge home or transfer to a step down unit. Premature infants are at increased risk of carnitine deficiency. Carnitine supplementation has been used for both prevention and treatment of apnea.

OBJECTIVES

To determine whether treatment with carnitine will reduce the frequency of apnea, the duration of ventilation and the duration of hospital stay in preterm infants with recurrent apnea.

SEARCH STRATEGY

Computerised searches were carried out by two reviewers independently. Searches were made of MEDLINE (1966 to May 2004), EMBASE (1980 to May 2004), CINAHL (1982-2004 June 2004,1st week), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2004), abstracts of annual meetings of the Society for Pediatric Research (1995-2004), and contacts were made with the subject experts.

SELECTION CRITERIA

Only randomized or quasi-randomized treatment trials of preterm infants with a diagnosis of recurrent apnea of prematurity were considered. Trials were included if they involved treatment with carnitine compared to placebo or no treatment, and measured at least one of the following outcomes: failure of resolution of apneas, the duration of ventilation and the duration of hospital stay.

DATA COLLECTION AND ANALYSIS

Two reviewers evaluated the papers for inclusion criteria and quality. Corresponding authors were contacted for further information where needed.

MAIN RESULTS

No eligible trials were identified.

REVIEWERS' CONCLUSIONS

Despite the plausible rationale for the treatment of apnea of prematurity with carnitine, there are insufficient data to support its use for this indication. Further studies are needed to determine the role of this treatment in clinical practice.