Higher versus lower protein intake in formula-fed low birth weight infants

Evaluation of Protein Content in the Diet of Amateur Male Bodybuilder

Public gyms and fitness clubs promote active lifestyles. At the same time, numerous nutritional errors and the phenomenon of incorrect supplementation are being observed among the given study group. Behavior can lead to malaise, injury, or lack of progression. One of the most serious mistakes is the incorrect level of protein in the diet. The aim of the study is to assess the quantity and quality of protein consumed by men undertaking recreational strength training in Szczecin. The study involved 35 men aged 18–35, practicing amateur strength training, from Szczecin (Poland). The author’s questionnaire collected information on supplementation, physical activity, and subjective assessment of nutritional knowledge. The obtained test results were subjected to statistical analysis performed in the Statistica12 program. On average, respondents consumed 1.8 g of protein/kg, with the highest recorded conversion rate of 3.7 g of protein/kg of body weight, and the lowest of 0.9 g/kg of body weight. Total protein consumption ranged from 70.2 to 295.7 g, and the average value was 147.8 g (22%), which differs from the study group, that is, 129–133 g, which gives 14% energy proteins. It was found that the protein supplementation, on average, provided 31% of the total protein intake of the study group. The results show inappropriate dietary behavior regarding food supplementation among the examined group. Further education on the nutritional value of the food and a healthy and balanced diet is being recommended for the individuals practicing strength sports.

Higher versus lower protein intake in formula-fed low birth weight infants

BACKGROUND

The ideal quantity of dietary protein for formula-fed low birth weight infants is still a matter of debate. Protein intake must be sufficient to achieve normal growth without leading to negative effects such as acidosis, uremia, and elevated levels of circulating amino acids.

OBJECTIVES

To determine whether higher (≥ 3.0 g/kg/d) versus lower (< 3.0 g/kg/d) protein intake during the initial hospital stay of formula-fed preterm infants or low birth weight infants (< 2.5 kilograms) results in improved growth and neurodevelopmental outcomes without evidence of short- or long-term morbidity. Specific objectives were to examine the following comparisons of interventions and to conduct subgroup analyses if possible. 1. Low protein intake if the amount was less than 3.0 g/kg/d. 2. High protein intake if the amount was equal to or greater than 3.0 g/kg/d but less than 4.0 g/kg/d. 3. Very high protein intake if the amount was equal to or greater than 4.0 g/kg/d.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 8), in the Cochrane Library (August 2, 2019); OVID MEDLINE Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily, and Ovid MEDLINE(R) (to August 2, 2019); MEDLINE via PubMed (to August 2, 2019) for the previous year; and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (to August 2, 2019). We also searched clinical trials databases and the reference lists of retrieved articles for randomized controlled trials (RCTs) and quasi-randomized trials.

SELECTION CRITERIA

We included RCTs contrasting levels of formula protein intake as low (< 3.0 g/kg/d), high (≥ 3.0 g/kg/d but < 4.0 g/kg/d), or very high (≥ 4.0 g/kg/d) in formula-fed hospitalized neonates weighing less than 2.5 kilograms. We excluded studies if infants received partial parenteral nutrition during the study period, or if infants were fed formula as a supplement to human milk.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane and the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We identified six eligible trials that enrolled 218 infants through searches updated to August 2, 2019. Five studies compared low (< 3 g/kg/d) versus high (3.0 to 4.0 g/kg/d) protein intake using formulas that kept other nutrients constant. The trials were small (n = 139), and almost all had methodological limitations; the most frequent uncertainty was about attrition. Low-certainty evidence suggests improved weight gain (mean difference [MD] 2.36 g/kg/d, 95% confidence interval [CI] 1.31 to 3.40) and higher nitrogen accretion in infants receiving formula with higher protein content (3.0 to 4.0 g/kg/d) versus lower protein content (< 3 g/kg/d), while other nutrients were kept constant. No significant differences were seen in rates of necrotizing enterocolitis, sepsis, or diarrhea. We are uncertain whether high versus low protein intake affects head growth (MD 0.37 cm/week, 95% CI 0.16 to 0.58; n = 18) and length gain (MD 0.16 cm/week, 95% CI -0.02 to 0.34; n = 48), but sample sizes were small for these comparisons. One study compared high (3.0 to 4.0 g/kg/d) versus very high (≥ 4 g/kg/d) protein intake (average intakes were 3.6 and 4.1 g/kg/d) during and after an initial hospital stay (n = 77). Moderate-certainty evidence shows no significant differences in weight gain or length gain to discharge, term, and 12 weeks corrected age from very high protein intake (4.1 versus 3.6 g/kg/d). Three of the 24 infants receiving very high protein intake developed uremia.

AUTHORS' CONCLUSIONS

Higher protein intake (≥ 3.0 g/kg/d but < 4.0 g/kg/d) from formula accelerates weight gain. However, limited information is available regarding the impact of higher formula protein intake on long-term outcomes such as neurodevelopment. Research is needed to investigate the safety and effectiveness of protein intake ≥ 4.0 g/kg/d.

Is neutrophil gelatinase-associated lipocalin a good diagnostic marker for renal injury in asphyxiated preterm infants?

BACKGROUND

The objective of this study is to evaluate the value of neutrophil gelatinase-associated lipocalin (NGAL) for becoming a good endogenous marker of renal function in asphyxial preterm babies.

MATERIALS AND METHODS

This is a two-center retrospective study. Between October 2016 and October 2017, 71 asphyxial preterm infants were included in asphyxia group. Seventy babies were randomly included in control group. Samples were tested at 24, 48, and 96 h after birth. Quantitative data were compared by independent sample t-test or repeated measures ANOVA. For qualitative data, Pearson's Chi-squared test was performed. Draw ROC and compare the area under the curve (AUC), 95% confidence interval for AUC, specificity (Spe), sensitivity (Sen), and Youden index (Sen+Spe-1) at 24-h, 48-h, and 96-h time points.

RESULTS

(1) There are no significant differences concerning on baseline data. However, blood gas, Apgar score, and resuscitation showed a significant difference (P < 0.05). (2) In 24-h samples, only uNGAL and estimated glomerular filtration rate (eGFR) showed differences between the two groups (P < 0.05). In 48-h samples, significant differences could be found in uKIM-1, uNGAL, blood urea nitrogen, and eGFR (P < 0.05). In 96-h samples, almost all indicators have significant differences except urine output and eGFR (P < 0.05). (3) All biomarkers showed statistical difference in the three time points (P < 0.05), but only uNGAL showed a downward trend after the increase of expression. (4) uNGAL has better Sen and Spe than other indicators (24-h AUC 0.870, Youden index 0.606; 48-h AUC 0.879, Youden index 0.692; and 96-h AUC 0.806, Youden index 0.606).

CONCLUSION

uNGAL has a better distinguishability in asphyxial neonates compared with other indicators. Certainly, a larger sample, prospective study is still needed.

Birth weight, gestational age and late adolescent liver function using twin status as instrumental variable in a Hong Kong Chinese birth cohort: "Children of 1997"

Birth weight (BW) is inversely associated with diabetes and liver function in Mendelian Randomization studies. Observationally, lower BW is usually also associated with poorer liver function. However, these studies could be confounded by socioeconomic position. Here we assessed if BW is associated with liver function in a unique population with little socio-economic patterning of BW, using both instrumental variable and an observational analysis. We used instrumental variable analysis (IVA) to assess the association of BW with liver function (alanine transaminase (ALT), alkaline phosphatase (ALP), bilirubin, and albumin) at ~17 years with twin status as an instrumental variable in the prospective population-representative "Children of 1997" birth cohort (n = 8327). We also conducted an observational analysis adjusted for sex, maternal age, maternal migrant status, smoking and parental socio-economic position. A generalized linear model with gamma family was used for ALT, ALP, and bilirubin because they are not normally distributed. Using IVA, BW was not associated with ALT, ALP or bilirubin, but was possibly negatively associated with albumin (-1.12 g/L, 95% confidence interval (CI) -2.08 to -0.16). Observationally, BW was negatively associated with ALT (-1.23 IU/L, 95% CI -2.16 to -0.30), ALP (-1.72 IU/L, 95% CI -3.43 to -0.01) and higher albumin (-0.23 g/L, 95% CI -0.40 to -0.06). Poor liver function may be a pathway by which the risks of lower BW are actuated. This insight might help identify post-natal targets of intervention to mitigate the adverse health effects of lower birth weight.

Impact of Early Nutrition on Body Composition in Children Aged 9.5 Years Born with Extremely Low Birth Weight

To evaluate body composition, metabolism and growth as well as their interaction with early nutrition in former extremely low birth weight infants (ELBW), we assessed qualitative and quantitative nutritional intake during initial hospitalization and infantile growth parameters in 61 former ELBW infants with a birth weight <1000 g. In two follow-up exams, physical and biochemical development were measured at 5.7 and at 9.5 years. At the second follow-up, in addition to biochemical reassessment, body composition was analyzed by dual-energy x-ray absorptiometry (DEXA). Protein intake between birth and discharge was associated with weight gain in the first six months of life (r = 0.51; p < 0.01). Weight catch-up preceded height catch-up. Protein intake in early infancy correlated highly significantly with abdominal fat mass (r = 0.49; p < 0.05), but not with lean body mass at 9.5 years (r = 0.30; not significant (n.s.). In contrast to nutrient intake, birth weight was associated with lean body mass (r = 0.433; p < 0.001). Early protein and carbohydrate intake were associated with high-density lipoprotein (HDL)-cholesterol, and early catch-up growth correlated with fasting insulin at follow-up. Stepwise linear regression demonstrated that protein intake predicted fat mass (p < 0.05), whereas only gender and birth weight standard deviation score (SDS) contributed significantly to lean body mass variation (p < 0.05). Our results suggest an important impact of early nutrient intake on body composition and metabolism in later childhood in ELBW children.

Does Amount of Protein in Formula Matter for Low-Birthweight Infants? A Cochrane Systematic Review

BACKGROUND

High protein intake may be associated with negative consequences such as acidosis, uremia, and elevated levels of circulating amino acids (eg, phenylalanine levels). We performed a systematic review of randomized controlled trials to determine whether formula-fed low-birthweight infants could tolerate protein intakes>or=3.0 g/kg/d in their initial hospital stay, without adverse consequences.

METHODS

Randomized controlled trials contrasting levels of protein intakes as low (<3.0 g/kg/d), high (>or=3.0 g/kg/d but <4.0 g/kg/d), or very high protein intake (>or=4.0 g/kg/d) while other nutrients were held constant, were identified through a systematic search of the literature. Standard methods of the Cochrane Collaboration were used by 2 independent reviewers, with the third reviewer facilitating consensus decision making.

RESULTS

A meta-analysis of 5 randomized trials indicated improved weight gain (weighted mean difference [WMD] 2.36 g/kg/d; 95% confidence interval [CI] 1.31-3.40) and higher nitrogen accretion (WMD 143.7 mg/kg/d; 95% CI 128.7-158.8) with high (>or=3.0 g/kg/d but <4.0 g/kg/d) compared with low (<3.0 g/kg/d) protein intakes while other nutrients were kept constant. No data were available for IQ or Bayley scores at 18 months or later or for very high protein intakes (>or=4.0 g/kg/d). No significant differences were seen in rates of necrotizing enterocolitis, sepsis, or diarrhea.

CONCLUSIONS

Accelerated weight and nitrogen accretion were noted with higher protein intakes in "healthy" formula-fed low-birthweight infants. This benefit could not be weighed against the adverse consequences of elevated blood urea nitrogen levels and increased metabolic acidosis and neurodevelopmental abnormalities.

Modification of nutrition strategy for improvement of postnatal growth in very low birth weight infants

Purpose

To identify the effects of modified parenteral nutrition (PN) and enteral nutrition (EN) regimens on the growth of very low birth weight (VLBW) infants.

Methods

The study included VLBW infants weighing <1,500 g, admitted to Chungnam National University Hospital between October 2010 and April 2014, who were alive at the time of discharge. Subjects were divided according to 3 periods: period 1 (n=37); prior to the PN and EN regimen being modified, period 2 (n=50); following the PN-only regimen modification, period 3 (n=37); following both PN and EN regimen modification. The modified PN regimen provided 3 g/kg/day of protein and 1 g/kg/day of lipid on the first day of life. The modified EN regimen provided 3.5-4.5 g/kg/day of protein and 150 kcal/kg/day of energy. We investigated growth rate, anthropometric measurements at 40 weeks postconceptional age (PCA) and the incidence of extrauterine growth restriction (EUGR) at 40 weeks PCA.

Results

Across the 3 periods, clinical characteristics, including gestational age, anthropometric measurements at birth, multiple births, sex, Apgar score, surfactant use and PDA treatment, were similar. Growth rates for weight and height, from time of full enteral feeding to 40 weeks PCA, were higher in period 3. Anthropometric measurements at 40 weeks PCA were greatest in period 3. Incidence of weight, height and head circumference EUGR at 40 weeks PCA decreased in period 3.

Conclusion

Beginning PN earlier, with a greater supply of protein and energy during PN and EN, is advantageous for postnatal growth in VLBW infants.

The effect of short-term high versus normal protein intake on whole-body protein synthesis and balance in children following cardiac surgery: a randomized double-blind controlled clinical trial

Background

Infants undergoing cardiac surgery are at risk of a negative protein balance, due to increased proteolysis in response to surgery and the cardiopulmonary bypass circuit, and limited intake. The aim of the study was to quantify the effect on protein kinetics of a short-term high-protein (HP) diet in infants following cardiac surgery.

Methods

In a prospective, double-blinded, randomized trial we compared the effects of a HP (5 g · kg⁻¹ · d⁻¹) versus normal protein (NP, 2 g · kg⁻¹ · d⁻¹) enteral diet on protein kinetics in children <24 months, on day 2 following surgical repair of congenital heart disease. Valine kinetics and fractional albumin synthesis rate (FSR_alb) were measured with mass spectrometry using [1-¹³C]valine infusion. The Mann–Whitney U test was used to investigate differences between group medians. Additionally, the Hodges-Lehmann procedure was used to create a confidence interval with a point estimate of median differences between groups.

Results

Twenty-eight children (median age 9 months, median weight 7 kg) participated in the study, of whom in only 20 subjects isotopic data could be used for final calculations. Due to underpowering of our study, we could not draw conclusions on the primary outcome parameters. We observed valine synthesis rate of 2.73 (range: 0.94 to 3.36) and 2.26 (1.85 to 2.73) μmol · kg⁻¹ · min⁻¹ in the HP and NP diet, respectively. The net valine balance was 0.54 (−0.73 to 1.75) and 0.24 (−0.20 to 0.63) μmol · kg⁻¹ · min⁻¹ in the HP and NP group. Between groups, there was no difference in FSR_alb. We observed increased oxidation and BUN in the HP diet, compared to the NP diet, as a plausible explanation of the metabolic fate of surplus protein.

Conclusions

It is plausible that the surplus protein in the HP group has caused the increase of valine oxidation and ureagenesis, compared to the NP group. Because too few patients had completed the study, we were unable to draw conclusions on the effect of a HP diet on protein synthesis and balance. We present our results as new hypothesis generating data.

Trial registration

Dutch Trial Register NTR2334.

Leucine is a major regulator of muscle protein synthesis in neonates

Approximately 10% of infants born in the United States are of low birth weight. Growth failure during the neonatal period is a common occurrence in low birth weight infants due to their inability to tolerate full feeds, concerns about advancing protein supply, and high nutrient requirements for growth. An improved understanding of the nutritional regulation of growth during this critical period of postnatal growth is vital for the development of strategies to improve lean gain. Past studies with animal models have demonstrated that muscle protein synthesis is increased substantially following a meal and that this increase is due to the postprandial rise in amino acids as well as insulin. Both amino acids and insulin act independently to stimulate protein synthesis in a mammalian target of rapamycin-dependent manner. Further studies have elucidated that leucine, in particular, and its metabolites, α-ketoisocaproic acid and β-hydroxy-β-methylbutyrate, have unique anabolic properties. Supplementation with leucine, provided either parenterally or enterally, has been shown to enhance muscle protein synthesis in neonatal pigs, making it an ideal candidate for stimulating growth of low birth weight infants.

Early aggressive nutrition enhances language development in very low-birthweight infants

BACKGROUND

Inadequate nutrition in very-low-birthweight (VLBW) infants is known to be associated with growth failure and poor neurological outcomes. We aimed to investigate the association of early aggressive protein and energy intakes with weight gain and 18-month neurodevelopmental outcomes in VLBW infants.

METHODS

A total of 90 infants among 129 infants who survived to discharge were included and divided into two groups (early aggressive nutrition [n = 52] vs conventional nutrition [n = 38]). Clinical findings were compared between the two groups and daily protein and energy intakes were collected for the first 4 weeks of life. Multiple regression analyses tested the association between weekly protein or energy intakes and the result of each category of the Denver Developmental Screening Test II at 18 months' corrected age or weight gain.

RESULTS

The early aggressive nutrition group had higher rates of normal language development and lower rates of growth failure (<10th percentile) at both 40 weeks' and 18 months' corrected age compared to the conventional nutrition group. After controlling for the confounding variables, higher first week protein and energy intakes each independently contributed to normal language development (odds ratio [95% confidence interval]; 9.4 [1.8-49.6] per 1 g/kg of protein increase and 1.7 [1.1-2.8] per 10 kcal/kg of energy increase). Higher first-week protein intake was associated with a higher weight at 40 weeks' corrected age (r = 0.41, P = 0.005).

CONCLUSIONS

This study demonstrates the importance of the protein and energy intakes in VLBW infants in the first week of life not only for growth but also for better language development.

Protein Intake and Growth in Preterm Infants: A Systematic Review

Objective. This review aimed to investigate the relationship between varying levels of enteral protein intake and growth in preterm infants, regardless of feeding method. Data Sources. Electronic databases were searched for relevant studies, as were review articles, reference lists, and text books. Study Selection. Trials were included if they were randomized or quasirandomized, participants were <37 weeks gestation at birth, and protein intakes were intentionally or statistically different between study groups. Trials reporting weight, length, and head circumference gains in infants fed formula, human milk, or fortified human milk were included. Data Extraction. Studies were categorized by feeding-type and relevant data were extracted into summary tables by one reviewer and cross-checked by a second. Data Synthesis. A meta-analysis could not be conducted due to extensive variability among studies; thus, results were synthesized graphically and narratively. Twenty-four trials met the inclusion criteria and were included in a narrative synthesis and 19 in a graphical synthesis of study results. Conclusions. There was extensive variability in study design, participant characteristics, and study quality. Nonetheless, results are fairly consistent that higher protein intake results in increased growth with graphical representation indicating a potentially linear relationship. Additionally, intakes as high as 4.5 g/kg/day were shown to be safe in infants weighing >1000 g.

Assessment of renal functional maturation and injury in preterm neonates during the first month of life

Worldwide, approximately 10% of neonates are born preterm. The majority of preterm neonates are born when the kidneys are still developing; therefore, during the early postnatal period renal function is likely reflective of renal immaturity and/or injury. This study evaluated glomerular and tubular function and urinary neutrophil gelatinase-associated lipocalin (NGAL; a marker of renal injury) in preterm neonates during the first month of life. Preterm and term infants were recruited from Monash Newborn (neonatal intensive care unit at Monash Medical Centre) and Jesse McPherson Private Hospital, respectively. Infants were grouped according to gestational age at birth: ≤28 wk (n = 33), 29-31 wk (n = 44), 32-36 wk (n = 32), and term (≥37 wk (n = 22)). Measures of glomerular and tubular function were assessed on postnatal days 3-7, 14, 21, and 28. Glomerular and tubular function was significantly affected by gestational age at birth, as well as by postnatal age. By postnatal day 28, creatinine clearance remained significantly lower among preterm neonates compared with term infants; however, sodium excretion was not significantly different. Pathological proteinuria and high urinary NGAL levels were observed in a number of neonates, which may be indicative of renal injury; however, there was no correlation between the two markers. Findings suggest that neonatal renal function is predominantly influenced by renal maturity, and there was high capacity for postnatal tubular maturation among preterm neonates. There is insufficient evidence to suggest that urinary NGAL is a useful marker of renal injury in the preterm neonate.

Protein intake and neurodevelopmental outcomes

There is a compelling body of literature that suggests that the provision of an inadequate amount of protein to preterm infants in the neonatal period has detrimental effects on the developing brain with the potential to result in long-term, neurodevelopmental sequelae. Although a great deal of indirect evidence implies that the provision of adequate amounts of protein may be associated with better neurodevelopmental outcomes, there remains a paucity of direct evidence that would allow us to draw any final conclusions.

High-protein formulas: evidence for use in preterm infants

Relatively high amounts of protein are required to achieve normal fractional protein synthetic rates during the late second through early third trimester of fetal growth. Once preterm infants achieve higher protein intakes for sustained periods, growth begins to approximate that of the normally growing fetus and long-term neurodevelopmental outcomes are improved. Preterm formulas have been developed that are enriched in protein. This review discusses several factors when using standard preterm formulas and high-protein preterm formulas in the neonatal intensive care unit, with an emphasis on quantity and quality of enteral protein delivery and risks to insufficient and/or excess protein administration.

Higher versus lower protein intake in formula-fed low birth weight infants

BACKGROUND

The ideal quantity of dietary protein for formula-fed low birth weight infants is still a matter of debate. Protein intake must be sufficient to achieve normal growth without negative effects such as acidosis, uremia, and elevated levels of circulating amino acids.

OBJECTIVES

To determine whether higher (≥ 3.0 g/kg/d) versus lower (< 3.0 g/kg/d) protein intake during the initial hospital stay of formula-fed preterm infants or low birth weight infants (< 2.5 kilograms) results in improved growth and neurodevelopmental outcomes without evidence of short- and long-term morbidity.To examine the following distinctions in protein intake. 1. Low protein intake if the amount was less than 3.0 g/kg/d. 2. High protein intake if the amount was equal to or greater than 3.0 g/kg/d but less than 4.0 g/kg/d. 3. Very high protein intake if the amount was equal to or greater than 4.0 g/kg/d.If the reviewed studies combined alterations of protein and energy, subgroup analyses were to be carried out for the planned categories of protein intake according to the following predefined energy intake categories. 1. Low energy intake: less than 105 kcal/kg/d. 2. Medium energy intake: greater than or equal to 105 kcal/kg/d and less than or equal to 135 kcal/kg/d. 3. High energy intake: greater than 135 kcal/kg/d.As the Ziegler-Fomon reference fetus estimates different protein requirements for infants based on birth weight, subgroup analyses were to be undertaken for the following birth weight categories. 1. < 800 grams. 2. 800 to 1199 grams. 3. 1200 to 1799 grams. 4. 1800 to 2499 grams.

SEARCH METHODS

The standard search methods of the Cochrane Neonatal Review Group were used. MEDLINE, CINAHL, PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library) were searched.

SELECTION CRITERIA

Randomized controlled trials contrasting levels of formula protein intake as low (< 3.0 g/kg/d), high (≥ 3.0 g/kg/d but < 4.0 g/kg/d), or very high (≥ 4.0 g/kg/d) in formula-fed hospitalized neonates weighing less than 2.5 kilograms were included. Studies were excluded if infants received partial parenteral nutrition during the study period or were fed formula as a supplement to human milk. Studies in which nutrients other than protein also varied were added in a post-facto analysis.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Neonatal Review Group were used.

MAIN RESULTS

Five studies compared low versus high protein intake. Improved weight gain and higher nitrogen accretion were demonstrated in infants receiving formula with higher protein content while other nutrients were kept constant. No significant differences were seen in rates of necrotizing enterocolitis, sepsis, or diarrhea.One study compared high versus very high protein intake during and after an initial hospital stay. Very high protein intake promoted improved gain in length at term, but differences did not remain significant at 12 weeks corrected age. Three of the 24 infants receiving very high protein intake developed uremia.A post-facto analysis revealed further improvement in all growth parameters in infants receiving formula with higher protein content. No significant difference in the concentration of plasma phenylalanine was noted between high and low protein intake groups. However, one study (Goldman 1969) documented a significantly increased incidence of low intelligence quotient (IQ) scores among infants of birth weight less than 1300 grams who received a very high protein intake (6 to 7.2 g/kg).

AUTHORS' CONCLUSIONS

Higher protein intake (≥ 3.0 g/kg/d but < 4.0 g/kg/d) from formula accelerates weight gain. However, limited information is available regarding the impact of higher formula protein intake on long-term outcomes such as neurodevelopmental abnormalities. Available evidence is not adequate to permit specific recommendations regarding the provision of very high protein intake (> 4.0 g/kg/d) from formula during the initial hospital stay or after discharge.

Early nutrition and weight gain in preterm newborns and the risk of retinopathy of prematurity

OBJECTIVE

To identify nutritional and weight gain limitations associated with retinopathy of prematurity (ROP) severity among very preterm newborns.

PATIENTS AND METHODS

1180 infants <28 weeks GA at birth with ROP examination results were grouped and analyzed by quartile of weekly total calorie, carbohydrate, protein, and lipid intake, as well as growth velocity between postnatal days 7 and 28 (adjusted for GA and birth weight Z-score). ROP was categorized by development of no, mild (

RESULTS

Greater risk for Type 1 ROP (risk/95% confidence intervals) was found for infants with lowest quartile receipt of lipids (2.1/1.1, 3.8), total calories (2.2/1.4, 3.6), and carbohydrates (1.7/1.1, 2.9). Development of zone 1 ROP was associated with lipid or total calorie intake in the lowest quartile, and development of stage 3 ROP was associated with lowest quartile of total calorie intake. Growth velocity in the lowest quartile was associated with increased risk of any ROP, including type 1 ROP.

CONCLUSION

The risk of developing severe ROP in extremely premature infants might be reduced by improving nutritional support, specifically targeting lipids and total calories, and perhaps by improving weight gain.

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Key Words Collapse

MESH Headings

• Female
• Humans
• Infant Nutritional Physiological Phenomena/physiology
• Infant, Extremely Premature/physiology
• Infant, Newborn
• Logistic Models
• Male
• Nutritional Status
• Prospective Studies
• Retinopathy of Prematurity/diagnosis
• Retinopathy of Prematurity/physiopathology
• Risk Assessment/methods
• Risk Assessment/statistics & numerical data
• Risk Factors
• Time Factors
• Weight Gain/physiology

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Grants

• 5U01NS040069-05 NINDS NIH HHS
• 2R01NS040069-06A2 NINDS NIH HHS
• R21 EY019253 NEI NIH HHS
• 5P30HD018655-28 NICHD NIH HHS
• 1R21EY019253-01 NEI NIH HHS
• P30 HD018655 NICHD NIH HHS
• U01 NS040069 NINDS NIH HHS

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Affiliation(s)

Deborah K VanderVeen Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Camilia R Martin
Reshma Mehendale
Elizabeth N Allred
Olaf Dammann
Alan Leviton

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Human milk for the premature infant

Premature infants are at risk for growth failure, developmental delays, necrotizing enterocolitis, and late-onset sepsis. Human milk from women delivering prematurely has more protein and higher levels of bioactive molecules. Human milk must be fortified for premature infants to achieve adequate growth. Mother's own milk improves growth and neurodevelopment, decreases the risk of necrotizing enterocolitis and late-onset sepsis, and should be the primary enteral diet for premature infants. Donor milk is a resource for premature infants whose mothers are unable to provide an adequate supply of milk. Challenges include the need for pasteurization, nutritional and biochemical deficiencies, and limited supply.

Biological determinants linking infant weight gain and child obesity: current knowledge and future directions

Childhood obesity rates have reached epidemic proportions. Excessive weight gain in infancy is associated with persistence of elevated weight status and later obesity. In this review, we make the case that weight gain in the first 6 mo is especially predictive of later obesity risk due to the metabolic programming that can occur early postpartum. The current state of knowledge regarding the biological determinants of excess infant weight gain is reviewed, with particular focus on infant feeding choice. Potential mechanisms by which different feeding approaches may program the metabolic profile of the infant, causing the link between early weight gain and later obesity are proposed. These mechanisms are likely highly complex and involve synergistic interactions between endocrine effects and factors that alter the inflammatory and oxidative stress status of the infant. Gaps in current knowledge are highlighted. These include a lack of data describing 1) what type of infant body fat distribution may impart risk and 2) how maternal metabolic dysfunction (obesity and/or diabetes) may affect milk composition and exert downstream effects on infant metabolism. Improved understanding and management of these early postnatal determinants of childhood obesity may have great impact on reducing its prevalence.

Excessive Leucine-mTORC1-Signalling of Cow Milk-Based Infant Formula: The Missing Link to Understand Early Childhood Obesity

Increased protein supply by feeding cow-milk-based infant formula in comparison to lower protein content of human milk is a well-recognized major risk factor of childhood obesity. However, there is yet no conclusive biochemical concept explaining the mechanisms of formula-induced childhood obesity. It is the intention of this article to provide the biochemical link between leucine-mediated signalling of mammalian milk proteins and adipogenesis as well as early adipogenic programming. Leucine has been identified as the predominant signal transducer of mammalian milk, which stimulates the nutrient-sensitive kinase mammalian target of rapamycin complex 1 (mTORC1). Leucine thus functions as a maternal-neonatal relay for mTORC1-dependent neonatal β-cell proliferation and insulin secretion. The mTORC1 target S6K1 plays a pivotal role in stimulation of mesenchymal stem cells to differentiate into adipocytes and to induce insulin resistance. It is of most critical concern that infant formulas provide higher amounts of leucine in comparison to human milk. Exaggerated leucine-mediated mTORC1-S6K1 signalling induced by infant formulas may thus explain increased adipogenesis and generation of lifelong elevated adipocyte numbers. Attenuation of mTORC1 signalling of infant formula by leucine restriction to physiologic lower levels of human milk offers a great chance for the prevention of childhood obesity and obesity-related metabolic diseases.

Executive summary of the workshop "Nutritional Challenges in the High Risk Infant"

In 2009, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) invited an expert panel to a workshop to address the current knowledge gaps and lack of evidence-based guidelines that preclude optimal nutritional care for infants in neonatal intensive care units. Since much research needs to be done in this complex area of science, the group was requested to propose new research to rectify current deficiencies in this field. This paper provides a summary of the workshop presentations and discussions.

Nutrition support in the pediatric surgical patient

This article deals with the nutritional needs of pediatric patients. It begins by discussing the caloric requirements of different pediatric patients and moves on to a breakdown of the specific nutrients required. It then progresses to a detailed description of the enteral and parenteral modalities for delivery of nutrition to pediatric patients. The article concludes with a discussion of specific problems and disorders encountered in pediatric surgical patients.

The level of protein in milk formula modifies ileal sensitivity to LPS later in life in a piglet model

Background

Milk formulas have higher protein contents than human milk. This high protein level could modify the development of intestinal microbiota, epithelial barrier and immune functions and have long-term consequences.

Methodology/Principal findings

We investigated the effect of a high protein formula on ileal microbiota and physiology during the neonatal period and later in life. Piglets were fed from 2 to 28 days of age either a normoprotein (NP, equivalent to sow milk) or a high protein formula (HP, +40% protein). Then, they received the same solid diet until 160 days. During the formula feeding period ileal microbiota implantation was accelerated in HP piglets with greater concentrations of ileal bacteria at d7 in HP than NP piglets. Epithelial barrier function was altered with a higher permeability to small and large probes in Ussing chambers in HP compared to NP piglets without difference in bacterial translocation. Infiltration of T cells was increased in HP piglets at d28. IL-1β and NF-κB sub-units mRNA levels were reduced in HP piglets at d7 and d28 respectively; plasma haptoglobin also tended to be reduced at d7. Later in life, pro-inflammatory cytokines secretion in response to high doses of LPS in explants culture was reduced in HP compared to NP piglets. Levels of mRNA coding the NF-κB pathway sub-units were increased by the challenge with LPS in NP piglets, but not HP ones.

Conclusions/Significance

A high protein level in formula affects the postnatal development of ileal microbiota, epithelial barrier and immune function in piglets and alters ileal response to inflammatory mediators later in life.

Growth, body composition and hormonal status of growing pigs exhibiting a normal or small weight at birth and exposed to a neonatal diet enriched in proteins

Small birth weight and excess of early protein intake are suspected to enhance later obesity risk. The present study was undertaken to determine the impact of neonatal diets differing in protein content on growth, body composition and hormonal status of 70-d-old pigs born with normal weight (NW) or small weight (SW). At 7 d of age, male and female suckled piglets were assigned to the NW (approximately 1·4 kg at birth) or SW (approximately 0·99 kg at birth) groups. They were fed milk replacers formulated to provide an adequate protein (AP) or a high protein (HP) supply for 3 weeks. From weaning to 70 d of age, all animals received ad libitum the same standard diet. Growth rates were higher (P < 0·05) in HP piglets than in AP piglets during formula feeding and remained higher (P < 0·05) only in HP male pigs thereafter. No difference in feed consumption was detected between groups during the periods examined. Carcass lipid content and the relative weight of perirenal adipose tissue did not differ between the AP and HP pigs. Whereas plasma leptin concentration was higher (P < 0·05) in HP pigs than in AP pigs with a marked difference in SW pigs, plasma insulin-like growth factor (IGF)-I concentration and expression of IGF system genes were not affected by the diets. In summary, a HP intake during the suckling period induced an increase in growth rate that persisted only in male pigs during the post-weaning period. This response was not associated with any difference in adiposity parameters in this period.

First-week protein and energy intakes are associated with 18-month developmental outcomes in extremely low birth weight infants

OBJECTIVE

We sought to evaluate the association between early protein and energy intake and neurodevelopment and growth of extremely low birth weight (<1000 g) infants.

STUDY DESIGN

Daily protein and energy intakes were collected by chart review for the first 4 weeks of life on 148 extremely low birth weight survivors. A total of 124 infants (84%) returned for evaluation at 18 months' corrected age. Bivariate analysis tested correlations between weekly protein or energy intakes and Bayley Mental Development Index, Psychomotor Development Index, or growth at 18 months. Separate regression models evaluated contributions of protein (grams per kilogram per day) and energy intake (kilojoules per kilogram per day) to the Mental Development Index, Psychomotor Development Index, and growth, while controlling for known confounders.

RESULTS

After adjusting for confounding variables, week 1 energy and protein intakes were each independently associated with the Mental Development Index. During week 1, every 42 kJ (10 kcal)/kg per day were associated with a 4.6-point increase in the Mental Development Index and each gram per kilogram per day in protein intake with an 8.2-point increase in the Mental Development Index; higher protein intake was also associated with lower likelihood of length <10th percentile.

CONCLUSIONS

Increased first-week protein and energy intakes are associated with higher Mental Development Index scores and lower likelihood of length growth restrictions at 18 months in extremely low birth weight infants. Emphasis should be placed on providing more optimal protein and energy during this first week.

Optimizing growth in the preterm infant

Most very low birth weight preterm infants experience postnatal growth failure in the neonatal ICU. In an attempt to minimize this phenomenon, the nutritional support of these infants has tended to become more aggressive in recent years and has become a focus of much study. Despite this attention, many questions remain unresolved. This article examines several of these issues, including the controversies regarding optimal postnatal growth velocity, early aggressive nutritional support, and the transition to enteral nutrition in preterm infants.

Proteomics- and metabolomics-based neonatal diagnostics in assessing and managing the critically ill neonate

The use of proteomic-based neonatal screening has been relatively limited until the present era and has focused primarily on the evaluation of newborns for inborn errors of metabolism. The future of proteomic-based screening seems to be much more encompassing, however. Tandem mass spectrometry and other related technologies are highly likely to be used in the evaluation of acute disease processes. Proteomics has the advantage over genomics of permitting a more direct look at an evolving disease process, because genomics primarily relates only the potential for a disease or abnormality to express itself. This article reviews the current uses of proteomics-based newborn evaluation and evaluates how this rapidly evolving area of medicine may be used to assess the fetus and the neonate in the near future.

Sodium bicarbonate: basically useless therapy

Common clinical practices often are unsupported by experimental evidence. One example is the administration of sodium bicarbonate to neonates. Despite a long history of widespread use, objective evidence that administration of sodium bicarbonate improves outcomes for patients in cardiopulmonary arrest or with metabolic acidosis is lacking. Indeed, there is evidence that this therapy is detrimental. This review examines the history of sodium bicarbonate use in neonatology and the evidence that refutes the clinical practice of administering sodium bicarbonate during cardiopulmonary resuscitation or to treat metabolic acidosis in the NICU.

Optimal protein and energy intakes in preterm infants

There is compelling evidence that current nutritional practice fails to provide sufficient dietary protein for preterm infants, especially extremely and very low birth weight infants. Nutrient requirements can be estimated by a variety of techniques, but most suggest that these infants will require a protein intake of 3.5-4.0 g/kg/d. Even when these infants are able to tolerate full enteral feeds, most currently available artificial milk formula or breast milk fortifiers will not ensure these protein requirements are met except when fed at high volumes. Energy requirements on the other hand may be currently met, and evidence from controlled studies suggests that intakes higher than 110-135 kcal/kg/d might not be beneficial. The data from studies on neonatal adiposity outcomes, and from studies examining relationship between early growth and later cardiovascular outcome, also suggest that excess nutrient intake might be harmful. In the light of this data, optimal intakes and protein-energy ratios require re-appraisal.

Special circumstances: trophic feeds, necrotizing enterocolitis and bronchopulmonary dysplasia

There are many unresolved issues regarding how to feed the extremely-low-birth-weight (ELBW) infant. Trophic feedings of small volumes of breast milk or formula do not appear to increase the incidence of necrotizing enterocolitis (NEC). For prevention of NEC, breast milk, antenatal steroids and fluid restriction each confers a benefit. Because the incidence of NEC is relatively low, to determine if a particular prevention strategy is effective, large numbers of infants would need to be enrolled in a prospective, randomized controlled trial, and such trials are rare. Candidate therapies for NEC prevention that warrant further study include oral immunoglobulins, probiotics, long-chain polyunsaturated fatty acids and arginine. Suboptimal nutrition in ELBW infants is common in the early postnatal period. This is also the most critical time for the development of bronchopulmonary dysplasia, when even brief periods of malnutrition have significant effects on lung development and growth.

Higher versus lower protein intake in formula-fed low birth weight infants

BACKGROUND

The ideal quantity of dietary protein for formula-fed low birth weight infants < 2.5 kilograms is still a matter of controversy and debate. In premature infants, the protein intake must be sufficient to achieve normal growth without negative effects such as acidosis, uremia, and elevated levels of circulating amino acids (e.g. phenylalanine levels). This systematic review evaluates the benefits and risks of higher (>= 3.0 g/kg/day) versus lower (< 3.0 g/kg/day) protein intakes during the initial hospital stay of formula-fed preterm infants < 2.5 kilograms.

OBJECTIVES

To determine whether higher (>= 3.0 g/kg/day) versus lower (< 3.0 g/kg/day) protein intakes during the initial hospital stay of formula-fed preterm infants < 2.5 kilograms result in improved growth and neurodevelopmental outcomes without evidence of short and long-term morbidity.

SEARCH STRATEGY

Two review authors searched MEDLINE (1966 - May 2005), CINAHL (1982 - May 2005), PubMed (1966 - May 2005), EMBASE (1980 - May 2005), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2005), abstracts, conferences and symposia proceedings from Society of Pediatric Research, and American Academy of Pediatrics. Cross references were reviewed independently for additional relevant titles and abstracts for articles up to fifty years old.

SELECTION CRITERIA

Randomized controlled trials contrasting levels of formula protein intakes as low (< 3.0 g/kg/day), high (=> 3.0 g/kg/day but < 4.0 g/kg/day), or very high protein intake (=> 4.0 g/kg/day) during hospitalization of neonates less than 2.5 kilograms at birth who were formula-fed. Studies were not included if infants received partial parenteral nutrition during the study period or were fed formula as a supplement to human milk. Given the small number of studies that met all inclusion criteria, studies in which nutrients other than protein also varied (> 10% relative difference) were added in a post-facto analysis.

DATA COLLECTION AND ANALYSIS

Two review authors used standard methods of the Cochrane Collaboration and of the Cochrane Neonatal Review Group to independently assess trial eligibility and quality, and extracted data. In a 3-arm trial where two groups fell within the same predesignated protein intake group, weighted means and pooled standard deviations were calculated.

MAIN RESULTS

The literature search identified 37 studies, of which five met all the inclusion criteria. All five studies compared low (< 3.0 g/kg/day) to high protein intakes (=> 3.0 g/kg/day but < 4.0 g/kg/day). The overall analysis revealed an improved weight gain (WMD 2.36 g/kg/day, 95% CI 1.31, 3.40) and higher nitrogen accretion (WMD 143.7 mg/kg/day, 95% CI 128.7, 158.8) in infants receiving formula with higher protein content while other nutrients were kept constant. None of the studies reported IQ or Bayley scores at 18 months or later. No significant differences were seen in rates of necrotizing enterocolitis, sepsis or diarrhea. Of three studies included in the post-facto analysis, only one could be included in the meta-analysis. The post-facto analysis revealed further improvement in all growth parameters in infants receiving formula with higher protein content (weight gain: WMD 2.53 g/kg/day, 95% CI 1.62, 3.45, linear growth: WMD 0.16 cm/week, 95% CI 0.03, 0.30, and head growth: WMD 0.23, 95% CI 0.12, 0.35). There was no significant difference (WMD 0.25, 95% CI -0.20, 0.70) in the concentration of plasma phenylalanine between the high and low protein intake groups. One study (Goldman 1969) in the post-facto analysis documented a significantly increased incidence of low IQ scores, below 90, in infants of birth weight less than 1300 grams who received a very high protein intake (6 to 7.2 g/kg/day).

AUTHORS' CONCLUSIONS

This systematic review suggests that higher protein intake (=> 3.0 g/kg/day but < 4.0 g/kg/day) from formula accelerates weight gain. Based on increased nitrogen accretion rates, this most likely indicates an increase in lean body mass. Although accelerated weight gain is considered to be a positive effect, increase in other outcome measures examined may represent a negative or ambivalent effect. These include elevated blood urea nitrogen levels and increased metabolic acidosis. Limited information was available regarding the impact of higher formula protein intakes on long term outcomes such as neurodevelopmental abnormalities. As determined in this review, existing research literature on this topic is not adequate to make specific recommendations regarding the provision of very high protein intake (> 4.0 g/kg/day) from formula.