Feeding preterm infants today for later metabolic and cardiovascular outcomes

Greater Early Gains in Fat-Free Mass, but Not Fat Mass, Are Associated with Improved Neurodevelopment at 1 Year Corrected Age for Prematurity in Very Low Birth Weight Preterm Infants

OBJECTIVE

This work investigates the relationship between early body composition changes and neurodevelopment at 1 year age corrected for prematurity (CA).

STUDY DESIGN

A prospective, longitudinal study to measure body composition weekly in 34 very low birth weight preterm infants using air displacement plethysmography, beginning when infants stabilized after birth until discharge. Neurodevelopmental testing (Bayley Scales of Infant Development-III) was performed at 12 months CA. Linear mixed effects models were used to obtain inpatient subject-specific changes in fat-free mass (FFM) and fat mass (FM), which were then used as predictors of Bayley subscale scores in subsequent linear regression models, adjusting for potential confounders. Protein and energy provision were calculated for the first week of life.

RESULTS

Greater FFM gains while inpatient were associated with improved cognitive and motor scores at 12 months CA (P = .002 for both). These relationships remained significant when adjusting for birth weight, gestational age, and intraventricular hemorrhage (P ≤ .05 for both). Similar analysis was performed for FM gains without significant findings. Increased provision of protein and calories during the first week of life was positively associated with FFM gains (P ≤ .01 for both), but not FM gains (P ≥ .2 for both), throughout hospitalization.

CONCLUSIONS

Increased FFM gains, but not FM gains, during hospitalization are associated with improved neurodevelopment at 12 months CA. As early FM gains may be associated with long-term risk, more research is needed to develop strategies that optimize FFM gains while minimizing FM gains in very low birth weight preterm infants.

Multi-nutrient fortification of human milk for preterm infants

BACKGROUND

Exclusively breast milk-fed preterm infants may accumulate nutrient deficits leading to extrauterine growth restriction. Feeding preterm infants with multi-nutrient fortified human breast milk rather than unfortified breast milk may increase nutrient accretion and growth rates and may improve neurodevelopmental outcomes.

OBJECTIVES

To determine whether multi-nutrient fortified human breast milk improves important outcomes (including growth and development) over unfortified breast milk for preterm infants without increasing the risk of adverse effects (such as feed intolerance and necrotising enterocolitis).

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2), MEDLINE, EMBASE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (until February 2016), as well as conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared feeding preterm infants with multi-nutrient (protein and energy plus minerals, vitamins or other nutrients) fortified human breast milk versus unfortified (no added protein or energy) breast milk.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group. We separately evaluated trial quality, data extracted by two review authors and data synthesised using risk ratios (RRs), risk differences and mean differences (MDs). We assessed the quality of evidence at the outcome level using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We identified 14 trials in which a total of 1071 infants participated. The trials were generally small and weak methodologically. Meta-analyses provided low-quality evidence that multi-nutrient fortification of breast milk increases in-hospital rates of growth (MD 1.81 g/kg/d, 95% confidence interval (CI) 1.23 to 2.40); length (MD 0.12 cm/wk, 95% CI 0.07 to 0.17); and head circumference (MD 0.08 cm/wk, 95% CI 0.04 to 0.12). Only very limited data are available for growth and developmental outcomes assessed beyond infancy, and these show no effects of fortification. The data did not indicate other potential benefits or harms and provided low-quality evidence that fortification does not increase the risk of necrotising enterocolitis in preterm infants (typical RR 1.57, 95% CI 0.76 to 3.23; 11 studies, 882 infants).

AUTHORS' CONCLUSIONS

Limited available data do not provide strong evidence that feeding preterm infants with multi-nutrient fortified breast milk compared with unfortified breast milk affects important outcomes, except that it leads to slightly increased in-hospital growth rates.

Risk factors associated with growth failure in the follow-up of very low birth weight newborns

OBJECTIVE

To determine risk factors during neonatal hospital stay and follow-up associated with failure to thrive in the first year of life of very low birth weight newborns.

METHODS

Study of preterm very low birth weight newborns followed from 2006 to 2013 in a public institutional hospital program. The study included newborns that attended at least one appointment in each of the three periods: Period I, up to 3 months of corrected age (CA); Period II, 4-6 months of CA; and Period III, 7-12 months of CA. The variables were analyzed by logistic regression with XLSTAT 2014 software (Microsoft®, WA, USA). Failure to thrive (Z-score below -2 SD) was classified as a dichotomous dependent variable (0 - failure/1 - success), while the other variables were classified as explanatory variables for the hospitalization periods and for each of the follow-up periods (I, II, and III).

RESULTS

Children born adequate for gestational age increased the chance of Z-score for weight at discharge>-2 SD (OR=10.217; 95% CI: 1.117-93.436). Metabolic bone disease and retinopathy of prematurity in Period I, as well as hospital readmissions in Periods II and III during follow-up increased the chance of Z-score<-2 SD.

CONCLUSION

Failure to thrive is influenced by intrauterine factors and, subsequently, by several morbidities, both in the birth and hospitalization period, as well as in the post-discharge period and thus, such variables should be prioritized in the follow-up.

Influence of gestational age and birth weight in neonatal cholesterol response to total parenteral nutrition

BACKGROUND

Premature and critically ill infants receiving total parenteral nutrition (TPN) are at risk for dyslipidemia, and altered cholesterol levels in early life may contribute to later cardiovascular risk. Data regarding plasma cholesterol response to TPN in young infants are lacking.

OBJECTIVE

To determine the changes in plasma cholesterol levels during the first week of life in infants receiving TPN and a comparison group of infants who did not receive TPN during routine care.

METHODS

In a prospective, pilot cohort study, 38 neonates (30 TPN vs. 8 No-TPN) underwent serial blood sampling during the first week of life. Gas chromatography-mass spectrometry was used to measure cholesterol in plasma and TPN administered to study participants.

RESULTS

Baseline cholesterol level was similar between groups. In contrast to infants who did not receive TPN, cholesterol levels during the first week of life were significantly higher than baseline in infants receiving TPN (maximum cholesterol response 34% vs. 103% change from baseline, No-TPN vs. TPN, respectively, P = .036). After adjusting for cumulative cholesterol received by infants receiving TPN, maximum cholesterol response remained inversely related to gestational age and birth weight (P < .05).

CONCLUSION

Plasma cholesterol significantly increases during the first week of life in neonates receiving TPN. A higher cholesterol response was induced by TPN in infants of lower gestational age and birth weight.

In Utero Origins of Hypertension: Mechanisms and Targets for Therapy

The developmental origins of health and disease theory is based on evidence that a suboptimal environment during fetal and neonatal development can significantly impact the evolution of adult-onset disease. Abundant evidence exists that a compromised prenatal (and early postnatal) environment leads to an increased risk of hypertension later in life. Hypertension is a silent, chronic, and progressive disease defined by elevated blood pressure (>140/90 mmHg) and is strongly correlated with cardiovascular morbidity/mortality. The pathophysiological mechanisms, however, are complex and poorly understood, and hypertension continues to be one of the most resilient health problems in modern society. Research into the programming of hypertension has proposed pharmacological treatment strategies to reverse and/or prevent disease. In addition, modifications to the lifestyle of pregnant women might impart far-reaching benefits to the health of their children. As more information is discovered, more successful management of hypertension can be expected to follow; however, while pregnancy complications such as fetal growth restriction, preeclampsia, preterm birth, etc., continue to occur, their offspring will be at increased risk for hypertension. This article reviews the current knowledge surrounding the developmental origins of hypertension, with a focus on mechanistic pathways and targets for therapeutic and pharmacologic interventions.

Health impact of catch-up growth in low-birth weight infants: systematic review, evidence appraisal, and meta-analysis

This study aimed to systematically review and appraise evidence on the short-term (e.g. morbidity, mortality) and long-term (obesity and non-communicable diseases, NCDs) health consequences of catch-up growth (vs. no catch-up growth) in individuals with a history of low birth weight (LBW).We searched MEDLINE, EMBASE, Global Health, CINAHL plus, Cochrane Library, ProQuest Dissertations and Thesis and reference lists. Study quality was assessed using the risk of bias assessment tool from the Agency for Health Care Research and Quality, and the evidence base was assessed using the GRADE tool. Eight studies in seven cohorts (two from high-income countries, five from low-middle-income countries) met the inclusion criteria for short-term (mean age: 13.4 months) and/or longer-term (mean age: 11.1 years) health outcomes of catch-up growth, which had occurred by 24 or 59 months. Of five studies on short-term health outcomes, three found positive associations between weight catch-up growth and body mass and/or glucose metabolism; one suggested reduced risk of hospitalisation and mortality with catch-up growth. Three studies on longer-term health outcomes found catch-up growth were associated with higher body mass, BMI or cholesterol. GRADE assessment suggested that evidence quantity and quality were low. Catch-up growth following LBW may have benefits for the individual with LBW in the short term, and may have adverse population health impacts in the long-term, but the evidence is limited. Future cohort studies could address the question of the consequences of catch-up growth following LBW more convincingly, with a view to informing future prevention of obesity and NCDs. © 2016 John Wiley & Sons Ltd.

[DOHaD: long-term impact of perinatal diseases (IUGR and prematurity)]

The first epidemiological studies showing a link between low birth weight and chronic diseases in adults did not distinguish the origins of low birth weight. A low birth weight may be the result of a premature birth. It can also be caused by an intrauterine growth restriction (IUGR). A child can be both preterm and IUGR. It is clear now that prematurity is an independent risk factor for programming chronic adult diseases. However, unlike adults born IUGR, adults born prematurely do not have an increased risk to develop metabolic syndrome (dyslipidemia or obesity). An increased risk of neurodevelopmental and psychiatric morbidity and hypertension is found after a premature birth. Mechanisms of chronic diseases programming are multiple: they involve both the cause of prematurity and IUGR such as infection / inflammation or placental insufficiency, but also consequences for therapeutic or nutritional strategies needed to support these children. This chapter describes the possible prevention of perinatal programming of noncommunicable diseases.

Working group reports: evaluation of the evidence to support practice guidelines for nutritional care of preterm infants-the Pre-B Project

The "Evaluation of the Evidence to Support Practice Guidelines for the Nutritional Care of Preterm Infants: The Pre-B Project" is the first phase in a process to present the current state of knowledge and to support the development of evidence-informed guidance for the nutritional care of preterm and high-risk newborn infants. The future systematic reviews that will ultimately provide the underpinning for guideline development will be conducted by the Academy of Nutrition and Dietetics' Evidence Analysis Library (EAL). To accomplish the objectives of this first phase, the Pre-B Project organizers established 4 working groups (WGs) to address the following themes: 1) nutrient specifications for preterm infants, 2) clinical and practical issues in enteral feeding of preterm infants, 3) gastrointestinal and surgical issues, and 4) current standards of infant feeding. Each WG was asked to 1) develop a series of topics relevant to their respective themes, 2) identify questions for which there is sufficient evidence to support a systematic review process conducted by the EAL, and 3) develop a research agenda to address priority gaps in our understanding of the role of nutrition in health and development of preterm/neonatal intensive care unit infants. This article is a summary of the reports from the 4 Pre-B WGs.

Leucine supplementation of a chronically restricted protein and energy diet enhances mTOR pathway activation but not muscle protein synthesis in neonatal pigs

Suboptimal nutrient intake represents a limiting factor for growth and long-term survival of low-birth weight infants. The objective of this study was to determine if in neonates who can consume only 70 % of their protein and energy requirements for 8 days, enteral leucine supplementation will upregulate the mammalian target of rapamycin (mTOR) pathway in skeletal muscle, leading to an increase in protein synthesis and muscle anabolism. Nineteen 4-day-old piglets were fed by gastric tube 1 of 3 diets, containing (kg body weight(-1) · day(-1)) 16 g protein and 190 kcal (CON), 10.9 g protein and 132 kcal (R), or 10.8 g protein + 0.2 % leucine and 136 kcal (RL) at 4-h intervals for 8 days. On day 8, plasma AA and insulin levels were measured during 6 post-feeding intervals, and muscle protein synthesis rate and mTOR signaling proteins were determined at 120 min post-feeding. At 120 min, leucine was highest in RL (P < 0.001), whereas insulin, isoleucine and valine were lower in RL and R compared to CON (P < 0.001). Compared to RL and R, the CON diet increased (P < 0.01) body weight, protein synthesis, phosphorylation of S6 kinase (p-S6K1) and 4E-binding protein (p-4EBP1), and activation of eukaryotic initiation factor 4 complex (eIF4E · eIF4G). RL increased (P ≤ 0.01) p-S6K1, p-4EBP1 and eIF4E · eIF4G compared to R. In conclusion, when protein and energy intakes are restricted for 8 days, leucine supplementation increases muscle mTOR activation, but does not improve body weight gain or enhance skeletal muscle protein synthesis in neonatal pigs.

A Common Genetic Variant in the Insulin Receptor Gene Is Associated with Eating Difficulties at 2 Years of Age in a Cohort of Preterm Infants

BACKGROUND/AIMS

Children born preterm are more likely than full-term infants to develop eating difficulties that can affect their growth. Although this behavior is certainly influenced by their fetal and postnatal history, a large individual variability exists that results from a complex interaction between genetic and environmental factors. We performed an original pilot study to identify common genetic variants associated with eating difficulties at 2 years of age in the POLYNUCA cohort of preterm infants.

METHODS

Eating behavior was assessed using a parental questionnaire in a cohort of 234 very preterm infants (including 38 pairs of twins). Eighty-two common single nucleotide polymorphisms (SNPs) were selected in a total of 40 candidate genes involved in the regulation of energy homeostasis and food intake.

RESULTS

Eating behavior was strongly correlated in monozygotic (r = 0.92, p = 0.001) but not dizygotic twins (r = 0.27, p = 0.14), suggesting a strong heritability of this trait. One SNP (rs11671975) in the insulin receptor (INSR) gene was significantly associated with eating behavior. This effect was maintained after adjustment for birth weight Z score and maternal education level, two factors that are associated with eating difficulties at 2 years of age.

CONCLUSION

The INSR gene is potentially associated with eating difficulties in preterm infants.

Impact of Nutrition on Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) remains a common morbidity of prematurity. Although the pathogenesis of BPD is recognized to be both multifactorial and complex, the role of nutrition in the pathophysiology of BPD is typically limited to management after a diagnosis has been made. Infants born small for gestational age and those who experience postnatal growth failure are more likely to have BPD. Therapies for lung disease, such as fluid restriction, diuretics, and corticosteroids, can negatively impact postnatal growth. Future research is needed to optimize nutritional strategies in the neonatal intensive care unit and following hospital discharge.

Biological Impact of Recent Guidelines on Parenteral Nutrition in Preterm Infants

OBJECTIVES

Recent guidelines for preterm neonates recommend early initiation of parenteral nutrition (PN) with high protein and relatively high caloric intake. This review considers whether these changes could influence homeostasis in very preterm infants during the first few postnatal weeks.

METHODS

This systematic review of relevant literature from searches of PubMed and recent guidelines was reviewed by investigators from several perinatal centers in France.

RESULTS

New recommendations for PN could be associated with metabolic acidosis via the increase in the amino acid ion gap, hyperchloremic acidosis, and ammonia acidosis. The introduction of high-intake amino acids soon after birth could induce hypophosphatemia and hypercalcemia, simulating a "repeat feeding-like syndrome" and could be prevented by the early intake of phosphorus, especially in preterm infants born after fetal growth restriction. Early high-dose amino acid infusions are relatively well tolerated in the preterm infant with regard to renal function. Additional studies, however, are warranted to determine markers of protein intolerance and to specify the optimal composition and amount of amino acid solutions.

CONCLUSIONS

Optimal PN following new guidelines in very preterm infants, despite their demonstrated benefits on growth, may induce adverse effects on ionic homeostasis. Clinicians should implement appropriate monitoring to prevent and/or correct them.

Application effect of extensively hydrolyzed milk protein formula and follow-up in preterm children with a gestational age of less than 34 weeks: study protocol for a randomized controlled trial

Background

The average incidence of preterm birth in the world is up to 11.1 %, and deaths of preterm children account for more than 50 % of neonatal deaths. Gastrointestinal function of preterm children with a gestational age less than 34 weeks is immaturely developed. For preterm children who can only be fed with formula due to their mothers’ sickness, choosing a suitable formula can not only meet the high nutritional needs of preterm children, but also solve their low gastrointestinal tolerability, and is thus very important.

Methods/Design

The study is a prospective, randomized, single-blind and controlled clinical trial. Preterm children with a gestational age less than 34 weeks meeting the inclusion criteria who cannot be breastfed will be included. To demonstrate the application effect of extensively hydrolyzed milk protein formula on the target population, preterm children will be randomized into two groups, 185 subjects in each group. The observation group will be fed with extensively hydrolyzed milk protein (100 % whey protein) formula, while the control group will be fed with preterm children’s formula until the children are discharged from the neonatal intensive care unit (NICU). All the formula involved in this study will be from Dumex. After discharge, both groups will be uniformly fed with formula for 0 to 6-month-old infants. For statistical analysis, a chi-square test and Student’s t test will be applied using SAS 9.4.

Discussion

This will be the first randomized controlled clinical study with long-term observation of the growth and development of preterm children during the NICU stay and at 3-month follow-up after discharge from the NICU. Results from this study will be used to determine whether the extensively hydrolyzed formula is more suitable for the low gastrointestinal tolerability of preterm children, and also whether feeding preterm children who are fed with such formula during the NICU stay with ordinary infant formula after discharge from the NICU would affect the normal growth and development of preterm children in the early stage of their lives.

Trial registration

This study was registered with the Chinese Clinical Trial Registry (http://www.chictr.org.cn/) with number ChiCTR-IOR-14005696, on December 22, 2014.

Nutritional support for premature infants in the neonatal intensive care unit

Nutritional support for premature infants in the neonatal intensive care unit setting is complex. Such infants have conditions unique to this period of the lifespan requiring specialized care management, both of which may impede the provision of adequate nutrition to support basal metabolic needs. Premature infants require optimum nutritional intake to support rapid growth during a time when they are not fully capable of tolerating it. This article reviews developmental anatomy, physiology, and the effect of premature delivery by systems; the challenges of providing adequate nutrition; and current evidence-based strategies to provide nutrition for premature infants during hospitalization.

Post-discharge formula feeding in preterm infants: A systematic review mapping evidence about the role of macronutrient enrichment

BACKGROUND & AIMS

Preterm infants are a heterogeneous group and many accumulate growth deficits before and after initial hospital discharge. Although this is associated with worse cognitive outcome, recent meta-analyses suggest that nutrient fortification of breast milk, or the use of nutrient and energy rich formulae after discharge exert little effect on growth and neurodevelopment. However, the complexity of study design, inclusion criteria and outcome parameters, combined with differences in formula composition mean that meta-analysis may overlook important effects of differing interventions in sub-groups.

METHODS

We systematically identified evidence and mapped the information on Participants, Intervention, Comparator, and Outcome (PICO) from 31 published studies illustrating the marked heterogeneity in study design and interventions next to outcomes on (quality of) growth and neurodevelopment.

RESULTS

Despite significant heterogeneity in study design, we found that nutrient enriched diets after discharge show no negative effects but frequently improve growth parameters at some point in the course of the study, in particular for boys. The data indicates that when energy requirements are adequate, increased protein results in increased growth and lean mass (LM) accretion; In particular, higher protein to energy ratios lead to increased lean mass accretion, and increased head circumference (HC) at one year. However, improvements in neurodevelopmental outcome were rarely seen.

CONCLUSION

This comprehensive evidence mapping approach to the field provides a broad but detailed overview of the currently available evidence. Furthermore, we identified key gaps in existing knowledge on the role of nutrient enrichment in the post-discharge period.

Managing the Human-Milk-Fed, Preterm, VLBW Infant at NICU Discharge

Feeding prematurely born infants after their stay in the neonatal intensive care unit (NICU) remains problematic. Growth in the NICU is almost always well below the intrauterine rate, and extrauterine growth restriction is common. Breastfeeding is difficult in the NICU, and human milk alone may not always provide adequate protein or minerals for optimal growth. At the time of NICU discharge, a regimen is needed that is supportive of both ongoing lactation and optimal nutrition. However, there is no one regimen that suits all babies and families. We propose a simplified algorithm to help guide the clinical team in deciding what dietary regimen is best suited for their patients.

Bilingualism as a potential strategy to improve executive function in preterm infants: a review

Preterm birth is associated with long-term deficits in executive functioning and cognitive performance. Using the model of brain plasticity as a theoretical framework, it is possible that preterm infants' neurodevelopmental sequelae can be altered. Evidence suggests that bilingualism confers cognitive advantages on executive functioning, so it is possible that bilingualism may improve preterm infants' neurodevelopment. However, bilingualism has only been studied in term children. This review examined literature that compared the performance of preterm-born children to term children and bilingual children to monolingual children on executive function tasks. To address cognitive disparities in preterm-born children, studies investigating the effect of bilingualism on preterm infants' executive functioning is warranted.

Boys who are born preterm show a relative lack of fat-free mass at 5 years of age compared to their peers

AIM

Prematurity is associated with features of metabolic syndrome in young adulthood. We investigated the body composition and blood pressure of children born preterm.

METHODS

A longitudinal, observational study was conducted with preterm infants who had a birth weight of <1500 g and a gestational age of <32 weeks. Growth and body composition were assessed by air displacement plethysmography at term equivalent age and at school age and were compared to those of 61 healthy, term breastfed subjects.

RESULTS

A total of 63 preterm infants were enrolled. At term equivalent age, growth and fat-free mass were lower in preterm infants than in term newborns, but fat mass was higher. At 5 years of age, children born preterm were still lighter and shorter than children born at term. When the results were analysed by gender, the fat-free mass index was lower in boys born preterm than in their peers (12.1 ± 1.1 versus 13.0 ± 1.0 kg/h(2) p < 0.005), whereas no difference was detected among girls. Diastolic blood pressure was higher in children born preterm than in children born at term (61.14 ± 7.8 vs 56.69 ± 8.2 mmHg, p = 0.009).

CONCLUSION

Boys born preterm showed a relative lack of fat-free mass at school age compared to their peers.

Dietary proteins and IGF I levels in preterm infants: determinants of growth, body composition, and neurodevelopment

It has been demonstrated that a high-protein diet in preterm born infants during the first weeks of life may enable a growth rate equal to that seen in utero and may also result in a better long-term neurodevelopmental outcome. This diet may limit immediate postnatal growth retardation and may hence lower the risk of increased fat deposition after birth leading to the metabolic syndrome in later life. Insulin-like growth factor I (IGF I) has proven to play an important role in early postnatal growth of preterm infants, but also seems to have a persisting influence on body composition in childhood. Furthermore, increased IGF I concentrations in preterm infants have been associated with improved neurodevelopmental outcome. This review will elaborate on the role of dietary proteins and IGF I on growth, body composition, and neurodevelopment of preterm infants. Possible causal pathways will be explored and areas for future research will be proposed.

Enhanced nutrient supply to very low birth weight infants is associated with improved white matter maturation and head growth

BACKGROUND

Extrauterine growth restriction is common among very low birth weight infants (VLBW, BW <1,500 g). Optimal postnatal nutrient supply is essential to limit growth restriction and ensure adequate growth and neurodevelopment.

OBJECTIVES

We compared an enhanced postnatal nutrient supply to a standard supply and evaluated the effects on growth velocity, head circumference growth and cerebral maturation - the latter by magnetic resonance diffusion tensor imaging (DTI). We hypothesized increased growth velocity, head circumference growth and decreased mean diffusivity (MD) in cerebral white matter (WM) areas, suggesting improved cerebral maturation among infants on the enhanced nutrient supply.

METHODS

In this randomized controlled trial, infants on the enhanced nutrient supply received increased amounts of energy, protein, fat, essential fatty acids and vitamin A until discharge. DTI was performed close to term equivalent age. Outcomes were growth velocity, head circumference growth and WM mean diffusivity.

RESULTS

Among the 50 included infants, 14 in the intervention group and 11 controls underwent a successful DTI. Infants on the enhanced diet achieved improved growth velocity (16.5 vs. 13.8 g/kg/day, p = 0.01) and increased head circumference (Δz score: 0.24 vs. -0.12, p = 0.15). A significantly lower MD was seen in a large WM area such as the superior longitudinal fasciculi (1.19 × 10(-3) vs. 1.24 × 10(-3) mm(2)/s, p = 0.04, adjusted for age when scanned).

CONCLUSIONS

Enhanced nutrient supply to VLBW infants is associated with improved growth velocity, increased head circumference growth and decreased regional WM mean diffusivity, suggesting improved maturation of cerebral connective tracts.

Perinatal programming prevention measures

Over the past 10 years, there has been outstanding scientific progress related to perinatal programming and its epigenetic effects in health, and we can anticipate this trend will continue in the near future. We need to make use and apply these achievements to human neurodevelopment via prevention interventions. Based on the concept of the interaction between genome and ambiome, this chapter proposes low-cost easy-implementation preventive strategies for maternal and infant health institutions.Breastfeeding and human milk administration are the first preventive measures, as has been reviewed in the policy statement of the American Academy of Pediatrics. Another strategy is the Safe and Family-Centered Maternity Hospitals initiative that promotes and empowers the inclusion of the families and the respect for their rights, especially during pregnancy and birth. (This change of paradigm was approved and is recommended by both United Nations Children's Fund, UNICEF, and Pan American Health Organization, PAHO.) Then, there is also an important emphasis given to the sacred hour-which highlights the impact of bonding, attachment, and breastfeeding during the first hour of life-the pain prevention and treatment in newborns, the control of the "new morbidity" represented by late preterm infants, and finally, the importance of avoiding intrauterine and extrauterine growth restriction. (However, there are not yet clear recommendations about nutritional interventions in order to diminish the potential metabolic syndrome consequence in the adult.).

Effects of breastfeeding on the risk factors for metabolic syndrome in preterm infants

Evidence suggests that breastfeeding during infancy lowers the risk of metabolic syndrome (MS) and its attendant risk factors in adult life. To investigate the influence of feeding type on the risk factors of MS, we assessed insulin sensitivity and lipid and apolipoprotein metabolism in preterm infants. Blood samples were collected from preterm infants at the time of discharge. Infants were separated into two groups: a breast milk (BM) group receiving ⩾90% of their intake from BM, and a mixed-fed (MF) group receiving ⩾50% of their intake from formula. The following indices were then compared between the two groups. Blood glucose and serum insulin levels were used to calculate the quantitative insulin sensitivity check index (QUICKI). We also measured serum total cholesterol (TC), low-density lipoprotein cholesterol (LDLc), high-density lipoprotein cholesterol (HDLc), apolipoprotein-A1 (apoA1) and apolipoprotein-B (apoB) levels, and the ratios of TC/HDLc, LDLc/HDLc and apoB/apoA1. The mean gestational age was 32.9 weeks at birth, and blood samples were collected at a mean corrected age of 37.4 weeks. There were 22 infants in the BM group and 19 in the MF group. QUICKI was significantly higher in the BM group. TC, HDLc and apoA1 were not significantly different between the groups, but LDLc and apoB levels were significantly higher in the BM group. The TC/HDLc, LDLc/HDLc and apoB/apoA1 ratios were significantly higher in the BM group. In preterm infants, the type of feeding exposure in the early postnatal period may influence glucose, lipid and apolipoprotein metabolism, and affect markers of MS.

Metabolic heritability at birth: implications for chronic disease research

Recent genome-wide association studies of the adult human metabolome have identified genetic variants associated with relative levels of several acylcarnitines, which are important clinical correlates for chronic conditions such as type 2 diabetes and obesity. We have previously shown that these same metabolite levels are highly heritable at birth; however, no studies to our knowledge have examined genetic associations with these metabolites measured at birth. Here, we examine, in 743 newborns, 58 single nucleotide polymorphisms (SNPs) in 11 candidate genes previously associated with differing relative levels of short-chain acylcarnitines in adults. Six SNPs (rs2066938, rs3916, rs3794215, rs555404, rs558314, rs1799958) in the short-chain acyl-CoA dehydrogenase gene (ACADS) were associated with neonatal C4 levels. Most significant was the G allele of rs2066938, which was associated with significantly higher levels of C4 (P = 1.5 × 10(-29)). This SNP explains 25 % of the variation in neonatal C4 levels, which is similar to the variation previously reported in adult C4 levels. There were also significant (P < 1 × 10(-4)) associations between neonatal levels of C5-OH and SNPs in the solute carrier family 22 genes (SLC22A4 and SLC22A5) and the 3-methylcrotonyl-CoA carboxylase 1 gene (MCCC1). We have replicated, in newborns, SNP associations between metabolic traits and the ACADS and SLC22A4 genes observed in adults. This research has important implications not only for the identification of rare inborn errors of metabolism but also for personalized medicine and early detection of later life risks for chronic conditions.

The challenge of understanding cerebral white matter injury in the premature infant

White matter injury in the premature infant leads to motor and more commonly behavioral and cognitive problems that are a tremendous burden to society. While there has been much progress in understanding unique vulnerabilities of developing oligodendrocytes over the past 30years, there remain no proven therapies for the premature infant beyond supportive care. The lack of translational progress may be partially explained by the challenge of developing relevant animal models when the etiology remains unclear, as is the case in this disorder. There has been an emphasis on hypoxia-ischemia and infection/inflammation as upstream etiologies, but less consideration of other contributory factors. This review highlights the evolution of white matter pathology in the premature infant, discusses the prevailing proposed etiologies, critically analyzes a sampling of common animal models and provides detailed support for our hypothesis that nutritional and hormonal deprivation may be additional factors playing critical and overlooked roles in white matter pathology in the premature infant.

Urinary metabolite profiles in premature infants show early postnatal metabolic adaptation and maturation

Objectives: Early nutrition influences metabolic programming and long-term health. We explored the urinary metabolite profiles of 48 premature infants (birth weight < 1500 g) randomized to an enhanced or a standard diet during neonatal hospitalization. Methods: Metabolomics using nuclear magnetic resonance spectroscopy (NMR) was conducted on urine samples obtained during the first week of life and thereafter fortnightly. Results: The intervention group received significantly higher amounts of energy, protein, lipids, vitamin A, arachidonic acid and docosahexaenoic acid as compared to the control group. Enhanced nutrition did not appear to affect the urine profiles to an extent exceeding individual variation. However, in all infants the glucogenic amino acids glycine, threonine, hydroxyproline and tyrosine increased substantially during the early postnatal period, along with metabolites of the tricarboxylic acid cycle (succinate, oxoglutarate, fumarate and citrate). The metabolite changes correlated with postmenstrual age. Moreover, we observed elevated threonine and glycine levels in first-week urine samples of the small for gestational age (SGA; birth weight < 10th percentile for gestational age) as compared to the appropriate for gestational age infants. Conclusion: This first nutri-metabolomics study in premature infants demonstrates that the physiological adaptation during the fetal-postnatal transition as well as maturation influences metabolism during the breastfeeding period. Elevated glycine and threonine levels were found in the first week urine samples of the SGA infants and emerged as potential biomarkers of an altered metabolic phenotype.

Preterm infants have altered adiponectin levels at term-equivalent age even if they do not present with extrauterine growth restriction

BACKGROUND/AIMS

This study aimed to investigate total adiponectin (T-Ad) and high-molecular-weight adiponectin (HMW-Ad) levels in preterm infants at term-equivalent age and to assess the relationship between adiponectin levels and early postnatal growth.

METHODS

The study included 43 term infants and 58 preterm infants born at 34 weeks' gestation or less. T-Ad and HMW-Ad levels were measured in the preterm infants at birth and at term-equivalent age, and in the term infants at birth. Adiponectin levels were statistically compared between preterm and term infants to evaluate the association between postnatal growth and changes in the adiponectin levels in preterm infants.

RESULTS

The T-Ad levels were higher and the ratio of HMW-Ad to T-Ad (HMW%) was lower in preterm infants at term-equivalent age than in term infants. Further, body weight SD score changes were positively associated with T-Ad and HMW-Ad increases in preterm infants from birth to term-equivalent age. The HMW% changes had a negative association only with HMW% in cord blood.

CONCLUSION

Preterm infants have altered adiponectin levels at term-equivalent age. Further, postnatal growth may contribute to adiponectin increases from birth to term-equivalent age, although HMW% changes might be regulated before birth at least up to term-equivalent age in preterm infants.

Accumulation of subcutaneous fat, but not visceral fat, is a predictor of adiponectin levels in preterm infants at term-equivalent age

BACKGROUND

Preterm infants have altered fat tissue development, including a higher percentage of fat mass and increased volume of visceral fat. They also have altered adiponectin levels, including a lower ratio of high-molecular-weight adiponectin (HMW-Ad) to total adiponectin (T-Ad) at term-equivalent age, compared with term infants.

AIMS

The objective of this study was to investigate the association between adiponectin levels and fat tissue accumulation or distribution in preterm infants at term-equivalent age.

STUDY DESIGN

Cross-sectional clinical study.

SUBJECTS

Study subjects were 53 preterm infants born at ≤34weeks gestation with a mean birth weight of 1592g.

OUTCOME MEASURES

Serum levels of T-Ad and HMW-Ad were measured and a computed tomography (CT) scan was performed at the level of the umbilicus at term-equivalent age to analyze how fat tissue accumulation or distribution was correlated with adiponectin levels.

RESULTS

T-Ad (r=0.315, p=0.022) and HMW-Ad levels (r=0.338, p=0.013) were positively associated with subcutaneous fat area evaluated by performing CT scan at term-equivalent age, but were not associated with visceral fat area in simple regression analyses. In addition, T-Ad (β=0.487, p=0.003) and HMW-Ad levels (β=0.602, p<0.001) were positively associated with subcutaneous fat tissue area, but they were not associated with visceral fat area also in multiple regression analyses.

CONCLUSION

Subcutaneous fat accumulation contributes to increased levels of T-Ad and HMW-Ad, while visceral fat accumulation does not influence adiponectin levels in preterm infants at term-equivalent age.

Is very preterm birth a risk factor for adult cardiometabolic disease?

The first infants to experience modern pre- and neonatal care are now in their thirties, an age at which the incidence of cardiometabolic disease is low. However, data from cohorts born preterm prior to the introduction of modern care suggest an increased risk of type 2 diabetes. For young adult cohorts of former very small or very preterm infants, there is accumulating evidence of increased risk factors for later cardiovascular disease, including higher blood pressure, lower lean body mass, impaired glucose regulation, and perhaps a more atherogenic lipid profile. Regarding lifestyle, adults born very small or very preterm undertake less non-conditioning physical activity and may have a lower intake of fruit and milk products. Any intervention reducing risk factors, in particular blood pressure and low physical activity, would have a substantial potential to reduce the lifetime disease burden in small preterm infants. There are now enough data to warrant an expert evaluation of the level of evidence for cardiometabolic disease in individuals born very small or very preterm, which has possible public health implications.

Enhanced feeding and diminished postnatal growth failure in very-low-birth-weight infants

OBJECTIVE

The aim of the present study was to determine whether an increased supply of energy, protein, essential fatty acids, and vitamin A reduces postnatal growth failure in very-low-birth-weight infants.

METHODS

Fifty infants with birth weight <1500 g were randomized to an intervention (n = 24) or a control (n = 26) feeding protocol within 24 hours after birth. Forty-four infants were included in the final analysis. This study was discontinued because of an increased occurrence of septicemia in the intervention group.

RESULTS

The intervention group had a lower mean birth weight (P = 0.03) and a higher proportion of infants small-for-gestational age (P = 0.04) than the control group. Other baseline characteristics were similar. The median (interquartile range) energy and protein supplies during the first 4 weeks of life were higher in the intervention group: 139 (128-145) versus 126 (121-128) kcal · kg · day (P < 0.001) and 4.0 (3.9-4.2) versus 3.2 (3.1-3.3) g · kg · day (P < 0.001). The infants in the intervention group regained birth weight faster (P = 0.001) and maintained their z scores for weight and head circumference from birth to 36 weeks' postmenstrual age (both P < 0.001). The median (interquartile range) growth velocity was 17.4 (16.3-18.6) g · kg · day in the intervention group and 13.8 (13.2-15.5) g · kg · day in the control group (P < 0.001). In line with the improved growth in the intervention group, the proportion of growth-restricted infants was 11 of 23 both at birth and at 36 weeks' postmenstrual age, whereas this proportion increased among the controls from 4 of 21 to 13 of 21 (P = 0.04).

CONCLUSIONS

Enhanced supply of energy, protein, essential fatty acids, and vitamin A caused postnatal growth along the birth percentiles for both weight and head circumference.

A systematic review of practice surveys on parenteral nutrition for preterm infants

Significant efforts have been made to improve the nutritional support of preterm infants in neonatal intensive care units (NICUs) to avoid cumulative nutritional deficits, reduce postnatal growth restriction, and promote optimal long-term development. The objective of this systematic review was to compare the characteristics and results of all surveys published in the past 10 y (2002-2012) that used a questionnaire to survey at least 2 NICUs receiving preterm infants with an intention to treat with parenteral nutrition (PN) and that reported information on at least 1 macronutrient. A total of 6 surveys were identified, which were conducted in the United States (n = 2) or Europe (n = 4). There was wide variability in the response rate (23-100%), with a higher response rate in the smaller studies (81-100%; 8-64 respondents) compared with the larger studies (23-58%; 296-809 respondents). Large differences were observed in the nutritional protocols both among the NICUs in the individual surveys and between surveys. PN was initiated on the first day of life (DOL) by only 24-54% of respondents (4 surveys) and within the second DOL by 67-94% of respondents (5 surveys). Lipids were initiated before the third DOL for 46-96% of respondents (3 surveys). The results of this systematic review suggest that continuous education is needed and that greater efforts are required to disseminate and implement guidelines. Repeated surveys are needed to highlight trends in clinical practices and level of compliance of NICUs with existing guidelines.

Quality of newborn care: adherence to guidelines for parenteral nutrition in preterm infants in four European countries

OBJECTIVE

The level of adherence to guidelines should be explored particularly in preterm infants for whom poor nutrition has major effects on outcomes in later life. The objective was to evaluate compliance to international guidelines for parenteral nutrition (PN) in preterm infants across neonatal intensive care units (NICUs) of four European countries.

DESIGN

Clinical practice survey by means of a questionnaire addressing routine PN protocols, awareness and implementation of guidelines.

SETTING

NICUs in the UK, Italy, Germany and France.

PARTICIPANTS

One senior physician per unit; 199 units which represent 74% of the NICUs of the four countries.

PRIMARY OUTCOME MEASURE

Adherence of unit protocol to international guidelines.

SECONDARY OUTCOME MEASURE

Factors that influence adherence to guidelines.

RESULTS

80% of the respondents stated that they were aware of some PN clinical practice guidelines. For amino acid infusion (AA), 63% of the respondents aimed to initiate AA on D0, 38% aimed to administer an initial dose ≥1.5 g/kg/day and 91% aimed for a target dose of 3 or 4 g/kg/day, as recommended. For parenteral lipids, 90% of the respondents aimed to initiate parenteral lipids during the first 3 days of life, 39% aimed to use an initial dose ≥1.0 g/kg/day and 76% defined the target dose as 3-4 g/kg/day, as recommended. Significant variations in PN protocols were observed among countries, but the type of hospital or the number of admissions per year had only a marginal impact on the PN protocols.

CONCLUSIONS

Most respondents indicated that their clinical practice was based on common guidelines. However, the initiation of PN is frequently not compliant with current recommendations, with the main differences being observed during the first days of life. Continuous education focusing on PN practice is needed, and greater efforts are required to disseminate and implement international guidelines.

Nutritional recommendations for the late-preterm infant and the preterm infant after hospital discharge

Early nutritional support of preterm infants is critical to life-long health and well being. Numerous studies have demonstrated that preterm infants are at increased risk of mortality and morbidity, including disturbances in brain development. To date, much attention has focused on enhancing the nutritional support of very low and extremely low birth weight infants to improve survival and quality of life. In most countries, preterm infants are sent home before their expected date of term birth for economic or other reasons. It is debatable whether these newborns require special nutritional regimens or discharge formulas. Furthermore, guidelines that specify how to feed very preterm infants after hospital discharge are scarce and conflicting. On the other hand, the late-preterm infant presents a challenge to health care providers immediately after birth when decisions must be made about how and where to care for these newborns. Considering these infants as well babies may place them at a disadvantage. Late-preterm infants have unique and often-unrecognized medical vulnerabilities and nutritional needs that predispose them to greater rates of morbidity and hospital readmissions. Poor or inadequate feeding during hospitalization may be one of the main reasons why late-preterm infants have difficulty gaining weight right after birth. Providing optimal nutritional support to late premature infants may improve survival and quality of life as it does for very preterm infants. In this work, we present a review of the literature and provide separate recommendations for the care and feeding of late-preterm infants and very preterm infants after discharge. We identify gaps in current knowledge as well as priorities for future research.

Growth curves: how to best measure growth of the preterm infant

Birth weight is one of the most important anthropometric measures in the evaluation of an infant. For the full-term infant, birth weight is compared with reference or standard growth curves that are constructed by plotting weight, length, and head circumference against postnatal age. Following a similar approach for preterm infants is less effective for a variety of reasons. Birth weight and other anthropometric measures used to evaluate an infant at birth are influenced by various maternal characteristics, the intrauterine milieu, and duration of gestation. Second, the causes of premature birth and their impact on birth weight are largely unknown. Third, gestational age is difficult to determine with full certainty. One approach that has been used to circumvent these issues is to use intrauterine growth reference curves. However, these curves do not really reflect "normal" growth because they were constructed using cross-sectional data from infants born prematurely and, as such, do not reflect the normal condition. Thus, there is a need to develop normative growth curves derived from "healthy" preterm infants that can be applied to neonates born prematurely. These should be updated periodically to reflect secular trends in maternal body weight, height, and overall health.