Effect of supplementation of preterm formula with long chain polyunsaturated Fatty acids on mineral balance in preterm infants

Polyunsaturated fatty acid supplementation in infancy for the prevention of allergy

BACKGROUND

Early dietary intakes may influence the development of allergic disease. It is important to determine if dietary polyunsaturated fatty acids (PUFAs) given as supplements or added to infant formula prevent the development of allergy.

OBJECTIVES

To determine the effect of higher PUFA intake during infancy to prevent allergic disease.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 9), MEDLINE (1966 to 14 September 2015), EMBASE (1980 to 14 September 2015) and CINAHL (1982 to 14 September 2015). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the use of a PUFA with no PUFA in infants for the prevention of allergy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality and extracted data from the included studies. We used fixed-effect analyses. The treatment effects were expressed as risk ratio (RR) with 95% confidence intervals (CI). We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

The search found 17 studies that assessed the effect of higher versus lower intake of PUFAs on allergic outcomes in infants. Only nine studies enrolling 2704 infants reported allergy outcomes that could be used in meta-analyses. Of these, there were methodological concerns for eight.In infants up to two years of age, meta-analyses found no difference in incidence of all allergy (1 study, 323 infants; RR 0.96, 95% CI 0.73 to 1.26; risk difference (RD) -0.02, 95% CI -0.12 to 0.09; heterogeneity not applicable), asthma (3 studies, 1162 infants; RR 1.04, 95% CI 0.80 to 1.35, I2 = 0%; RD 0.01, 95% CI -0.04 to 0.05, I2 = 0%), dermatitis/eczema (7 studies, 1906 infants; RR 0.93, 95% CI 0.82 to 1.06, I2 = 0%; RD -0.02, 95% CI -0.06 to 0.02, I2 = 0%) or food allergy (3 studies, 915 infants; RR 0.81, 95% CI 0.56 to 1.19, I2 = 63%; RD -0.02, 95% CI -0.06 to 0.02, I2 = 74%). There was a reduction in allergic rhinitis (2 studies, 594 infants; RR 0.47, 95% CI 0.23 to 0.96, I2 = 6%; RD -0.04, 95% CI -0.08 to -0.00, I2 = 54%; number needed to treat for an additional beneficial outcome (NNTB) 25, 95% CI 13 to ∞).In children aged two to five years, meta-analysis found no difference in incidence of all allergic disease (2 studies, 154 infants; RR 0.69, 95% CI 0.47 to 1.02, I2 = 43%; RD -0.16, 95% CI -0.31 to -0.00, I2 = 63%; NNTB 6, 95% CI 3 to ∞), asthma (1 study, 89 infants; RR 0.45, 95% CI 0.20 to 1.02; RD -0.20, 95% CI -0.37 to -0.02; heterogeneity not applicable; NNTB 5, 95% CI 3 to 50), dermatitis/eczema (2 studies, 154 infants; RR 0.65, 95% CI 0.34 to 1.24, I2 = 0%; RD -0.09 95% CI -0.22 to 0.04, I2 = 24%) or food allergy (1 study, 65 infants; RR 2.27, 95% CI 0.25 to 20.68; RD 0.05, 95% CI -0.07 to 0.16; heterogeneity not applicable).In children aged two to five years, meta-analysis found no difference in prevalence of all allergic disease (2 studies, 633 infants; RR 0.98, 95% CI 0.81 to 1.19, I2 = 36%; RD -0.01, 95% CI -0.08 to 0.07, I2 = 0%), asthma (2 studies, 635 infants; RR 1.12, 95% CI 0.82 to 1.53, I2 = 0%; RD 0.02, 95% CI -0.04 to 0.09, I2 = 0%), dermatitis/eczema (2 studies, 635 infants; RR 0.81, 95% CI 0.59 to 1.09, I2 = 0%; RD -0.04 95% CI -0.11 to 0.02, I2 = 0%), allergic rhinitis (2 studies, 635 infants; RR 1.02, 95% CI 0.83 to 1.25, I2 = 0%; RD 0.01, 95% CI -0.06 to 0.08, I2 = 0%) or food allergy (1 study, 119 infants; RR 0.27, 95% CI 0.06 to 1.19; RD -0.10, 95% CI -0.20 to -0.00; heterogeneity not applicable; NNTB 10, 95% CI 5 to ∞).

AUTHORS' CONCLUSIONS

There is no evidence that PUFA supplementation in infancy has an effect on infant or childhood allergy, asthma, dermatitis/eczema or food allergy. However, the quality of evidence was very low. There was insufficient evidence to determine an effect on allergic rhinitis.

Zinc and copper requirements in preterm infants: an examination of the current literature

BACKGROUND

Zinc and copper are essential for preterm infants, but recommended requirements from different groups vary widely. Recommended zinc intakes have steadily increased over the years. Although this would be expected to impair copper absorption, recommended copper intakes have not risen in parallel.

OBJECTIVES

To systematically review the literature on zinc and copper retention in preterm infants; to examine the effect on zinc intake on copper retention; and to estimate the zinc and copper intakes required to meet the levels of zinc and copper retention required for normal growth.

DESIGN

Studies reporting zinc and/or copper retention in preterm infants (<36 weeks of gestation) during the first 120 days of life were identified using PubMed. Only studies reporting net retention were included.

RESULTS

Fourteen studies on zinc retention reporting data on 45 different groups were identified. Eleven studies (32 groups) were identified reporting copper retention. Zinc retention was significantly higher at higher zinc intakes, and higher in formula-based diets than in human milk based diets. Zinc intakes of between 1.8-2.4 mg/kg/d (from formula based diets) and 2.3-2.4 mg/kg/d (from human-milk based diets) were required to achieve adequate zinc retention. Copper retention was significantly positively correlated with copper intake and significantly negatively correlated with zinc intake. At the zinc intakes suggested previously (1.8-2.4, 2.3-2.4 mg/kg/d), copper intakes of between 200 and 250 mcg/kg/d are required to ensure adequate copper retention.

CONCLUSIONS

Our results support the higher zinc intakes recommended in recent guidelines. However, they suggest that recommended copper intakes have not kept pace with increasing zinc intakes, and that preterm infants may need higher copper intakes than currently recommended.

Selected macro/micronutrient needs of the routine preterm infant

Requirements for optimal nutrition, especially for micronutrients, are not well defined for premature infants. The "reference fetus," developed by Ziegler et al,(1) has served as a model to define nutritional needs and studies designed to determine nutrient requirements. Revision of nutrient requirements and provision of optimal nutrition may lead to improved outcomes in preterm infants. Appropriate provision of nutrients also may help prevent nutritional disorders, such as metabolic bone disease and anemia. In this review, we discuss calcium, phosphorus, magnesium, vitamin D, iron, and copper, and define optimal intakes based on the available published data.

Effect of long-chain polyunsaturated fatty acid supplementation of preterm infants on disease risk and neurodevelopment: a systematic review of randomized controlled trials

BACKGROUND

Supplementation of preterm formulas with long-chain polyunsaturated fatty acids (LCPUFAs) is based on their effectiveness to increase blood status and improve visual outcomes. Dispute remains over their efficacy on global development.

OBJECTIVE

The objective was to compare the effects of LCPUFA-supplemented with those of control formulas on neurodevelopment and diseases associated with prematurity.

DESIGN

We systematically reviewed randomized controlled trials involving preterm infants that tested LCPUFA-supplemented formulas. The weighted mean differences (WMDs) in neurodevelopmental scores and relative risk (RR) of disease were calculated to compare infants fed LCPUFA-supplemented formula with those fed control formula.

RESULTS

No clear differences in Bayley Scales of Infant Development (BSID) scores were observed between groups. Mental development of LCPUFA-supplemented infants was 3.4 points higher than that of control infants with BSID version II (WMD: 3.44; 95% CI: 0.56, 6.31; P = 0.02; n = 879), although it was driven by 2 trials with large effect sizes and wide CIs. Psychomotor development was lower in supplemented infants tested with BSID version I (WMD: -7.99; 95% CI: -14.00, -1.99; P = 0.009; n = 87); however, it was limited by small sample sizes. No differences in the RR of sepsis (1.08; 95% CI: 0.79, 1.46; P = 0.63; n = 1333) or in the RR of necrotizing enterocolitis (1.13; 95% CI: 0.62, 2.04; P = 0.69; n = 1333) were found. Similarly, the risks of retinopathy of prematurity, intraventricular hemorrhage, and bronchopulmonary dysplasia were not different between groups, but data were limited by small sample sizes and trials with an increased risk of bias.

CONCLUSIONS

LCPUFA-supplemented formula does not alter the risk of NEC or sepsis. Further work is needed to determine the extent of benefit of LCPUFA-supplemented formula on the mental development of preterm infants.

Dietary arachidonic acid and docosahexaenoic acid elevate femur calcium and reduce zinc content in piglets

Specific dietary polyunsaturated fatty acids (PUFAs) and long chain PUFAs (LCPUFAs) elevate femur calcium content and enhance calcium balance. Mother's milk is associated with enhanced calcium balance and contains LCPUFAs; arachidonic acid (AA), and docosahexanoic acid (DHA). However, the effect of AA and DHA on calcium metabolism and other bone minerals during infancy is unknown. Thus, piglets received one of four formulas (15 d): control or with AA:DHA (0.5:0.1 g, 1.0:0.2 g, or 2.0:0.4 g/100 g of fat). Calcium absorption, femur mineral composition, and urinary mineral excretion. Main effects identified using two-way analysis of variance (ANOVA) and post hoc analysis conducted using Duncan's multiple range test. Significant effects of diet were observed in femur calcium and zinc content, but not calcium absorption, urinary mineral excretion, femur ash weight, femur phosphorus, or femur magnesium content. The piglets receiving AA:DHA as 1.0:0.2 g/100 g of fat had 1.9% higher mg calcium/g of ash, but 8.6% lower mug zinc/g of ash compared with control. Thus, AA:DHA in a ratio of 5:1 does not affect mineral accretion, but AA plus DHA, in amounts similar to the upper limit of human milk, might be detrimental to bone mineralization over time due to lower zinc.

Body composition in preterm infants who are fed long-chain polyunsaturated fatty acids: a prospective, randomized, controlled trial

The objective of this study was to evaluate growth and body composition of premature infants who were fed formulas with arachidonic acid (ARA; 20:4n6) and docosahexaenoic acid (DHA; 22:6n3) to 1 y of gestation-corrected age (CA). Preterm infants (750-1800 g birth weight and <33 wk gestational age) were assigned within 72 h of first enteral feeding to one of three formulas: control (n = 22), DHA+ARA from fish/fungal oil [DHA+ARA(FF); n = 20], or DHA+ARA from egg/fish oil [DHA+ARA(EF); n = 18]. Human milk feeding was allowed on the basis of the mother's choice. Infants were fed breast milk and/or preterm formulas with or without 0.26% DHA and 0.42% ARA to term CA followed by breast milk or postdischarge preterm formulas with or without 0.16% DHA and 0.42% ARA to 12 mo CA. Body composition was measured by dual-energy x-ray absorptiometry. There were no significant differences among the three study groups at any time point in weight, length, or head circumference. Bone mineral content and bone mineral density did not differ among groups. At 12 mo CA, infants who were fed DHA+ARA-supplemented formulas had significantly greater lean body mass (p < 0.05) and significantly less fat mass (p < 0.05) than infants who were fed the unsupplemented control formula. The DHA+ARA-supplemented formulas supported normal growth and bone mineralization in premature infants who were born at <33 wk gestation. Preterm formulas that had DHA+ARA at the levels and ratios in this study and were fed to 1 y CA led to increased lean body mass and reduced fat mass by 1 y of age.