Postnatal RBC arachidonic and docosahexaenoic acids deficiencies are associated with higher risk of neonatal morbidities and mortality in preterm infants

Fatty Acid Profile and Genetic Variants of Proteins Involved in Fatty Acid Metabolism Could Be Considered as Disease Predictor

Circulating fatty acids (FA) have an endogenous or exogenous origin and are metabolized under the effect of many enzymes. They play crucial roles in many mechanisms: cell signaling, modulation of gene expression, etc., which leads to the hypothesis that their perturbation could be the cause of disease development. FA in erythrocytes and plasma rather than dietary FA could be used as a biomarker for many diseases. Cardiovascular disease was associated with elevated trans FA and decreased DHA and EPA. Increased arachidonic acid and decreased Docosahexaenoic Acids (DHA) were associated with Alzheimer's disease. Low Arachidonic acid and DHA are associated with neonatal morbidities and mortality. Decreased saturated fatty acids (SFA), increased monounsaturated FA (MUFA) and polyunsaturated FA (PUFA) (C18:2 n-6 and C20:3 n-6) are associated with cancer. Additionally, genetic polymorphisms in genes coding for enzymes implicated in FA metabolism are associated with disease development. FA desaturase (FADS1 and FADS2) polymorphisms are associated with Alzheimer's disease, Acute Coronary Syndrome, Autism spectrum disorder and obesity. Polymorphisms in FA elongase (ELOVL2) are associated with Alzheimer's disease, Autism spectrum disorder and obesity. FA-binding protein polymorphism is associated with dyslipidemia, type 2 diabetes, metabolic syndrome, obesity, hypertension, non-alcoholic fatty liver disease, peripheral atherosclerosis combined with type 2 diabetes and polycystic ovary syndrome. Acetyl-coenzyme A carboxylase polymorphisms are associated with diabetes, obesity and diabetic nephropathy. FA profile and genetic variants of proteins implicated in FA metabolism could be considered as disease biomarkers and may help with the prevention and management of diseases.

Decreased Levels of Erythrocyte Membrane Arachidonic and Docosahexaenoic Acids Are Associated With Retinopathy of Prematurity

Purpose

Retinopathy of prematurity (ROP) can lead to blindness. Arachidonic acid (ARA) and docosahexaenoic acid (DHA) regulate retinal inflammation and angiogenesis. The aim of this study was to investigate red blood cell membrane (RBCM) ARA and DHA in preterm infants.

Methods

This prospective observational study divided infants into groups by ROP severity and RBCM ARA and DHA means and terciles.

Results

Although the mean ± SD RBCM ARA was different between groups (no ROP, 17.9% ± 0.7%, vs. type 2 ROP, 17.4% ± 0.8%, vs. type 1 ROP, 16.7% ± 1.0%; P < 0.001), the mean RBCM DHA was similar (P = 0.161). Infants with type 1 ROP were more likely to be in the lowest ARA and DHA terciles than in the highest (ARA, 44% vs. 5.6%; DHA, 22% vs. 5.6%). ARA and DHA declined over the first month of life in all ROP groups. At week 1, ARA was lower in the type 1 and type 2 ROP groups compared with the no-ROP group (18% ± 2% and 19% ± 3% vs. 21% ± 2%, respectively; P < 0.05 for all). At week 2, DHA and ARA were lower in the type I ROP group compared with the no-ROP group (3% ± 1% vs. 4% ± 1%, P = 0.03 and 16% ± 1% vs. 19% ± 1%, respectively; P < 0.01). A RBCM ARA% ≥ 17 was associated with a 45% reduction in any ROP. As the estimated 4-week ARA% mean increased by 1%, the odds of ROP decreased by 70% (odds ratio = 0.30; 95% confidence interval, 0.1-0.7).

Conclusions

Infants with severe ROP have lower ARA and DHA levels than infants without ROP. ARA and DHA may act synergistically to protect against ROP.

Effects of storage practices on long-chain polyunsaturated fatty acids and lipid peroxidation of preterm formula milk

BACKGROUND

Preterm formula milk (FM) is often prepared in advance, potentially affecting nutritional quality. Long-chain polyunsaturated fatty acids (LCPUFAs), important for brain and immune system function, are prone to lipid peroxidation, which correlates with comorbidities of prematurity. The effects of clinical storage practices on LCPUFA content and lipid peroxidation of preterm FM were investigated.

METHODS

UK liquid and powder preterm FM (2017) (from two manufacturers) were subjected to routine storage conditions (liquid: refrigeration ≤10 h; powder: weekly preparation in accordance with the manufacturer's instructions and refrigeration ≤24 h for 4 weeks). LCPUFA content, thiobarbituric acid reactive substances and 4-hydroxy-2-nonenal (HNE) content were analysed.

RESULTS

Storage did not significantly decrease LCPUFA content. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition recommended LCPUFA intake, whereas in utero accretion rates could not be achieved with both FM brands (liquid and powder). Lipid peroxidation was evident on opening, with 6× higher levels in powder. No effect of ≤10-h refrigeration on peroxidation was seen in liquid FM. In powder FM, it increased over refrigeration (HNE opening: 6.5-9.7 µg mL^-1 versus day 28, 24 h: 16.6-36.5 µg mL^-1 ) with a significant interaction between storage time and refrigeration (P = 0.015), with higher HNE at 4 h on days 0, 7, 14 and 21 (all P < 0.05).

CONCLUSIONS

The results suggest that preterm FM and storage conditions do not support in utero accretion rates for LCPUFAs. Although the results suggest different susceptibility of liquid and powder FM to peroxidation upon refrigeration, they are too preliminary to make specific recommendations. We suggest minimising storage time of fresh and prepared powder FM, wherever possible.

H. Smith L, Puttonen H, Fyhr IM, Sävman K, Nilsson AK, Klevebro S. Docosahexaenoic Acid and Arachidonic Acid Levels Are Associated with Early Systemic Inflammation in Extremely Preterm Infants

Fetal and early postnatal inflammation have been associated with increased morbidity in extremely preterm infants. This study aimed to demonstrate if postpartum levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) were associated with early inflammation. In a cohort of 90 extremely preterm infants, DHA and AA in cord blood, on the first postnatal day and on postnatal day 7 were examined in relation to early systemic inflammation, defined as elevated C-reactive protein (CRP) and/or interleukin-6 (IL-6) within 72 h from birth, with or without positive blood culture. Median serum level of DHA was 0.5 mol% (95% CI (confidence interval) 0.2–0.9, P = 0.006) lower than the first postnatal day in infants with early systemic inflammation, compared to infants without signs of inflammation, whereas levels of AA were not statistically different between infants with and without signs of inflammation. In cord blood, lower serum levels of both DHA (correlation coefficient −0.40; P = 0.010) and AA (correlation coefficient −0.54; p < 0.001) correlated with higher levels of IL-6. Levels of DHA or AA did not differ between infants with and without histological signs of chorioamnionitis or fetal inflammation. In conclusion, serum levels of DHA at birth were associated with the inflammatory response during the early postnatal period in extremely preterm infants.

Omega-3 Fatty Acids in Pregnancy-The Case for a Target Omega-3 Index

Scientific societies recommend increasing intake of docosahexaenoic acid (DHA) by 200 mg/day during pregnancy. However, individually, clinical events correlate quite strongly with levels of eicosapentaenoic acid (EPA) and DHA in blood, but these levels poorly correlate with amounts ingested. EPA and DHA in erythrocytes (Omega-3 Index) have a low biologic variability. If analyzed with a standardized analytical procedure (HS-Omega-3 Index^®), analytical variability is low. Thus, the largest database of any fatty acid analytical method was provided. Pregnant women in Germany had a mean Omega-3 Index below the target range suggested for cardiovascular disease of 8–11%, with large interindividual variation, and quite independent of supplementation with EPA and DHA. In Germany, premature birth is a major health issue. Premature birth and other health issues of pregnant women and their offspring correlate with levels of EPA and DHA in blood and can be reduced by increasing intake of EPA and DHA, according to individual trials and pertinent meta-analyses. Very high intake or levels of EPA and DHA may also produce health issues, like bleeding, prolonged gestation, or even premature birth. While direct evidence remains to be generated, evidence from various scientific approaches supports that the target range for the Omega-3 Index of 8–11% might also pertain to pregnancy and lactation.

Long-Chain Polyunsaturated Fatty Acids and Lipid Peroxidation Products in Donor Human Milk in the United Kingdom: Results From the LIMIT 2-Centre Cross-Sectional Study

BACKGROUND

Donor human milk (DHM) is used as alternative to maternal milk to feed preterm infants; however, it may provide less long-chain (LC) polyunsaturated fatty acids (PUFAs) and more oxidized lipids, which may be detrimental to preterm infant health and development. Levels have not been reported for DHM in the United Kingdom.

METHODS

DHM (n = 19) from 2 neonatal units, preterm milk from a neonatal unit (n = 10), and term milk from the community (n = 11) were analyzed for fatty acids, malondialdehyde, 4-hydroxy-2-nonenal, and hexanal.

STUDY REGISTRATION

NCT03573531.

RESULTS

DHM had significantly lower absolute LCPUFA content than term (P < .001) and significantly lower ω-3 PUFAs than preterm milk (P < .05), although relative LCPUFA composition did not differ. Exclusive DHM feeding leads to significantly lower fat (3.7 vs 6.7 g/d) and LCPUFA (docosahexaenoic acid [DHA]: 10.6 vs 16.8 mg/d; arachidonic acid [ARA]: 17.4 vs 25.2 mg/d) intake than recommended by the European Society for Pediatric Gastroenterology, Hepatology and Nutrition, and provides 17.3% and 43.1% of the in utero accreted ARA and DHA. DHM had the highest proportion of lipid peroxidation.

CONCLUSIONS

This study confirms that DHM in the United Kingdom has insufficient LCPUFAs for preterm infants. It demonstrates for the first time that DHM has the highest level of lipid peroxidation, compared with preterm or term milk. This has important implications for preterm infant nutrition, as exclusive DHM feeding might not be suitable long term and may contribute to the development of major preterm neonatal morbidities.

Intravenous Fish Oil and Serum Fatty Acid Profiles in Pediatric Patients With Intestinal Failure-Associated Liver Disease

BACKGROUND

Intravenous fish oil (FO) treats pediatric intestinal failure-associated liver disease (IFALD). There are concerns that a lipid emulsion composed of ω-3 fatty acids will cause an essential fatty acid deficiency (EFAD). This study's objective was to quantify the risk for abnormal fatty acid concentrations in children treated with FO.

METHODS

Inclusion criteria for this prospective study were children with intestinal failure. Intravenous soybean oil (SO) was replaced with FO for no longer than 6 months. Serum fatty acids were analyzed using linear and logistic models, and compared with age-based norms to determine the percentage of subjects with low and high concentrations.

RESULTS

Subjects (n = 17) started receiving FO at a median of 3.6 months (interquartile range 2.4-9.6 months). Over time, α-linolenic, linoleic, arachidonic, and Mead acid decreased, whereas docosahexaenoic and eicosapentaenoic acid increased (P < 0.001 for all). Triene-tetraene ratios remained unchanged (P = 1). Although subjects were 1.8 times more likely to develop a low linoleic acid while receiving FO vs SO (95% CI: 1.4-2.3, P < 0.01), there was not a significant risk for low arachidonic acid. Subjects were 1.6 times more likely to develop high docosahexaenoic acid while receiving FO vs SO; however, this was not significant (95% CI: 0.9-2.6, P = 0.08).

CONCLUSION

In this cohort of parenteral nutrition-dependent children, switching from SO to FO led to a decrease in essential fatty acid concentrations, but an EFAD was not evident. Low and high levels of fatty acids developed. Further investigation is needed to clarify if this is clinically significant.

Increased docosahexaenoic acid and n-3 polyunsaturated fatty acids in milk from mothers of small for gestational age preterm infants

The study aimed to test whether or not milk fatty acid composition in mothers of small for gestational age (SGA) infants is similar to that in mothers of adequate for gestational age (AGA) infants. Thirty three mothers of SGA preterm infants and 66 mothers of AGA preterm infants were included. Milk and plasma fatty acids were analyzed using capillary gas chromatography. Milk DHA (0.68 ± 0.37 vs. 0.44 ± 0.24; p < 0.01) was higher and n-6:n-3 PUFA ratio (12.0 ± 4.64 vs. 16.0 ± 6.32; p < 0.05) was lower in mothers of SGA infants. Plasma ARA and DHA were increased in mothers of SGA infants and decreased in their infants. Milk ARA or DHA was positively related to the correspondent fatty acid in plasma (r = 0.374, p = 0.010 for ARA and r = 0.690, p < 0.001 for DHA). Breast milk in mothers of preterm infants born SGA is enriched in DHA and n-3 PUFA. Breastfeeding SGA preterm infant with own mother's milk is recommended.