Reference values of whole-blood fatty acids by age and sex from European children aged 3-8 years

Establishment of a measurement system to evaluate breast milk transfer of biological agents using dry filter paper: A multi-institutional study

AIMS

Information on breastfeeding and safety of biologics in infants is lacking due to difficulties in case collection. We evaluated methods for determining the concentration of biologics in breast milk using a dry filter method that can simplify the collection, storage and transport of breast milk.

METHODS

To generate dried filter paper (DFP) samples, approximately 30 μL of breast milk was placed onto a Whatman 903 card and punched out. After extraction, the supernatant was measured using an enzyme-linked immunosorbent assay. Three concentrations of each drug were prepared in liquid breast milk (LBM) and DFP samples to determine their stability up to 28 days after storage at 2-8°C or -20°C for LBM and 25 ± 5°C for DFP. LBM and DFP samples were also provided by nursing mothers using biologics during lactation, and drug concentrations in both samples were compared. The agreement between the two measurement methods was confirmed by Bland-Altman analysis.

RESULTS

Breast milk was provided by 12 mothers who used biologics (tocilizumab, abatacept, etanercept, golimumab, sarilumab and belimumab). The coefficients of variation for within-run and between-run precision for the six drugs were within 15% for both LBM and DFP, and accuracy was within 90%-110% of the quality controls. After 28 days, concentrations remained at more than 90%. The difference between the values obtained by each method was within the acceptable range of error (-12.1 to +16.6 ng/mL).

CONCLUSIONS

A method for determining the concentration of biologics using DFP is expected to help improve pharmacotherapy for lactating women.

Lipid profile variability in children at different ages measured in dried blood spots

Dried blood spot (DBS) is a minimally invasive sampling technique that has several advantages over conventional venipuncture/arterial blood sampling. More recently, DBS has also been applied for lipidomics analysis, but this is an area that requires further research. The few works found in the literature on lipidomics of DBS samples performed the analysis in adult samples, leaving pediatric ages unmapped. The objective of this study was to assess the variability of the lipid profile (identified by high-resolution C18 RP-LC-MS/MS) of DBS at pediatric age (0-10 days, 2-18 months, and 3-13 years) and to identify age-related variations. The results revealed that the lipidomic signature of the three age groups is significantly different, especially for a few species of neutral lipids and phosphatidylcholines. The main contributors to the differentiation of the groups correspond to 3 carnitine (Car), 2 cholesteryl ester (CE), 2 diacylglycerol (DG), 2 triacylglycerol (TG), 3 phosphatidylcholine (PC), 1 ether-linked PC, 1 phosphatidylethanolamine (PE), 1 ether-linked PE and 1 phosphatidylinositol (PI) species, all with statistically significant differences. Additionally, lipid species containing linoleic acid (C18:2) were shown to have significantly lower levels in the 0-10 days group with a gradual increase in the 2-18 month, reaching the highest concentrations in the 3-13 year group. The results of this study highlighted the adaptations of the lipid profile at different pediatric ages. These results may help improve understanding of the evolution of lipid metabolism throughout childhood and should be investigated further.

Fatty acid uptake in Trypanosoma brucei: Host resources and possible mechanisms

Trypanosoma brucei spp. causes African Sleeping Sickness in humans and nagana, a wasting disease, in cattle. As T. brucei goes through its life cycle in its mammalian and insect vector hosts, it is exposed to distinct environments that differ in their nutrient resources. One such nutrient resource is fatty acids, which T. brucei uses to build complex lipids or as a potential carbon source for oxidative metabolism. Of note, fatty acids are the membrane anchoring moiety of the glycosylphosphatidylinositol (GPI)-anchors of the major surface proteins, Variant Surface Glycoprotein (VSG) and the Procyclins, which are implicated in parasite survival in the host. While T. brucei can synthesize fatty acids de novo, it also readily acquires fatty acids from its surroundings. The relative contribution of parasite-derived vs. host-derived fatty acids to T. brucei growth and survival is not known, nor have the molecular mechanisms of fatty acid uptake been defined. To facilitate experimental inquiry into these important aspects of T. brucei biology, we addressed two questions in this review: (1) What is known about the availability of fatty acids in different host tissues where T. brucei can live? (2) What is known about the molecular mechanisms mediating fatty acid uptake in T. brucei? Finally, based on existing biochemical and genomic data, we suggest a model for T. brucei fatty acid uptake that proposes two major routes of fatty acid uptake: diffusion across membranes followed by intracellular trapping, and endocytosis of host lipoproteins.

Whole blood fatty acid profile of young subjects and adherence to the Mediterranean diet: an observational cohort study

Background

Relatively little is known about the physiological whole blood fatty acid composition in young people. Likewise, few studies have addressed the question of correlations between Mediterranean diet (MedDiet) adherence and blood fatty acids in childhood.

Methods

The fatty acid profile in whole blood from subjects, 46 days-19 years old (n = 152), without acute, chronic, or inflammatory diseases was analysed by gas chromatography. Dietary data was extracted from a 24-h recall in a subgroup of subjects (n = 60) into a modified Diet Quality Index for Children (KIDMED) questionnaire to evaluate MedDiet adherence. The cohort was divided into three age groups: < 2, 2- < 10, and 10–19 years. Kruskal-Wallis test and Bonferroni post hoc test were used to check for age group fatty acid differences. For correlations, Spearman’s correlation coefficient and partial Spearman’s correlation coefficient were used.

Results

Linoleic acid, EPA, DHA, palmitic acid, and total saturated fatty acids were stable over age groups. Dihomo-gamma-linolenic acid (DGLA), arachidonic acid (AA), total polyunsaturated FAs (PUFA), and total omega-6 PUFA increased from age group < 2 years; alpha-linolenic acid, total omega-3 PUFA, oleic acid, and total monounsaturated FAs decreased. Adherence to the MedDiet was at low-medium level in 91.7% of the subjects. In the age group 2- < 10 yrs., the degree of adherence correlated positively with total MUFA and PUFA balance, negatively with total PUFA, total n6-PUFA, AA/DHA, AA/EPA, and n6/n3. Age did not influence the correlations as to PUFA balance and AA/EPA.

Conclusions

Increased FA proportions with age were seen in the n6-series of PUFA. The n3-FA species decreased or were stable. The vast majority of the subjects with dietary data, 92%, obtained a KIDMED score indicative of low-medium adherence to the MedDiet. The score correlated negatively with various n6-species, i.e. the MedDiet suppressed circulating n6-PUFA. Whole blood may be used to investigate FAs and MedDiet adherence correlations which may be applied in the study of health issues in childhood.

Blood Fatty Acids Profile in MIS-C Children

MIS-C (multisystem inflammatory syndrome in children) linked to SARS-CoV-2 infection, is a pathological state observed in subjects younger than 21 years old with evidence of either current SARS-CoV-2 infection or exposure within the 4 weeks prior to the onset of symptoms, the presence of documented fever, elevated markers of inflammation, at least two signs of multisystem involvement, and, finally, lack of an alternative diagnosis. They share with adult COVID-19 patients the presence of altered markers of inflammation, but unlike most adults the symptoms are not pulmonary but are affecting several organs. Lipid mediators arising from polyunsaturated fatty acids (PUFA) play an important role in the inflammatory response, with arachidonic acid-derived compounds, such as prostaglandins and leukotrienes, mainly pro-inflammatory and ω3 PUFA metabolites such as resolvins and protectins, showing anti-inflammatory and pro-resolution activities. In order to assess potential alterations of these FA, we evaluated the blood fatty acid profile of MIS-C children at admission to the hospital, together with biochemical, metabolic and clinical assessment. All the patients enrolled showed altered inflammatory parameters with fibrinogen, D-dimer, NT-proBNP, ferritin, aspartate aminotransferase (AST), C-reactive protein (CRP) and TrygIndex levels over the reference values in all the subjects under observation, while albumin and HDL-cholesterol resulted below the normal range. Interestingly, linoleic acid (LA), arachidonic acid (AA) and the ω3 PUFA docosahexaenoic acid (DHA) results were lower in our study when compared to relative amounts reported in the other studies, including from our own laboratory. This significant alteration is pointing out to a potential depletion of these PUFA as a result of the systemic inflammatory condition typical of these patients, suggesting that LA- and AA-derived metabolites may play a critical role in this pathological state, while ω3 PUFA-derived pro-resolution metabolites in these subjects may not be able to provide a timely, physiological counterbalance to the formation of pro-inflammatory lipid mediators. In conclusion, this observational study provides evidence of FA alterations in MIS-C children, suggesting a significant contribution of ω6 FA to the observed inflammatory state, and supporting a potential dietary intervention to restore an appropriate balance among the FAs capable of promoting the resolution of the observed inflammatory condition.

Exploring correlations between neuropsychological measures and domain-specific consistency in associations with n-3 LCPUFA status in 8-9 year-old boys and girls

Long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) have in some studies been associated with cognitive and socioemotional outcomes in children, but results are inconsistent possibly due to the use of different tests and potential gender-specific effects. The objective of this cross-sectional study was to explore overall patterns in neuropsychological scores as well as correlations between scores within specific domains, and to examine potential gender differences and consistency in associations with n-3 LCPUFA status. In 199 Danish 8–9 year-old children, we performed a large battery of tests and questionnaires on attention, processing speed, executive functions, memory, and socioemotional traits, and measured erythrocyte fatty acid composition. Principal component analyses (PCA) showed that most of the variation in both cognitive performance and socioemotional traits was explained by overall performance, followed by speed-accuracy trade off and externalizing vs. internalizing problems, respectively. Boys had higher speed, lower attention and higher externalizing problem scores than girls. Measures of performance within both processing speed and attention domains correlated moderately, whereas no correlations were found for measures of executive functions apart from some weak correlations for impulsivity. Parent-rated scores for both externalizing and internalizing problems correlated strongly, whereas correlations with child-rated scores were weak. Scores within specific domains did not consistently associate with n-3 LCPUFA, except for processing speed measures which all pointed to faster processing with increased n-3 LCPUFA status. Gender differences in the associations were observed for attention and impulsivity. Child- but not parent-rated internalizing and social problems tended to associate directly with n-3 LCPUFA, supported by increased internalizing problems measured by the PCA component. In conclusion, measures of speed and attention seem to represent these domains in general, whereas single measures of more complex cognitive functions should be interpreted with caution. One approach could be to use multiple tests and create multivariate scores to guide interpretations. Furthermore, the results indicate a need to consider both parent- and child-rated socioemotional scores and gender differences in neuropsychological functions e.g. in investigations of n-3 LCPUFA effects.

Is high oily fish intake achievable and how does it affect nutrient status in 8-9-year-old children?: the FiSK Junior trial

PURPOSE

Most children do not meet dietary guidelines for fish intake. Fish is the main source of EPA (20:5n-3), DHA (22:6n-3) and vitamin D, but may replace better iron sources such as meat. We investigated if intake of 300 g/week oily fish was achievable in children and how it affected their nutrient status. Additionally, we validated a fish food frequency questionnaire (FFQ) by correlations against EPA + DHA in red blood cells (RBC).

METHODS

In a randomised 12-week trial, 199 children (8-9 years) received oily fish or poultry (control) to be eaten five times/week. We measured dietary intake and analysed fasting RBC EPA + DHA, serum 25-hydroxyvitamin D (25(OH)D), blood haemoglobin and plasma ferritin.

RESULTS

197 (99%) children completed the study. The median (25th-75th percentile) intake was 375 (325-426) and 400 (359-452) g/week oily fish and poultry, respectively. The fish group increased their intake of EPA + DHA by 749 (593-891) mg/day and vitamin D by 3.1 (1.6-3.8) µg/day. Endpoint RBC EPA + DHA was 2.3 (95% CI 1.9; 2.6) fatty acid %-point higher than the poultry group (P < 0.001). The fish group avoided the expected 25(OH)D winter decline (P < 0.001) and had 23%-point less vitamin D insufficiency (winter subgroup, n = 82). Haemoglobin and ferritin decreased slightly in both groups (P < 0.05), but the number of children with low values did not change (P > 0.14). FFQ estimates moderately reflected habitual intake (r = 0.28-0.35) and sufficiently captured intervention-introduced changes in intake (r > 0.65).

CONCLUSION

Oily fish intake of 300 g/week was achievable and improved children's EPA + DHA and 25(OH)D status, without markedly compromising iron status. These results justify public health initiatives focusing on children's fish intake.

Clinical application of the dried milk spot method for measuring tocilizumab concentrations in the breast milk of patients with rheumatoid arthritis

AIMS

Tocilizumab (TCZ), a humanized anti-interleukin-6 receptor monoclonal antibody, is used to treat rheumatic diseases. There is limited information about the administration of TCZ during lactation. The dried spot method, a simple technique for processing biological samples which involves placement of a drop of specimen onto filter paper, has been used in clinical pharmacology to determine various drug concentrations. This study examined the feasibility of sample collection using the dried milk spot (DMS) method for obtaining data about the transfer of TCZ into breast milk.

METHODS

Concentrations of TCZ determined using DMSs prepared by patients were compared with those using liquid breast milk.

RESULTS

In an enzyme-linked immunosorbent assay of TCZ in DMSs, the accuracy ranged from 93.0% to 113.8% and the precision ranged from 0.3% to 8.4%. All concentrations of TCZ were within 15% of the reference value when analyzed on separate days. TCZ in DMSs at room temperature, 4°C, and -20°C were stable for 28 days. Extracted TCZ concentrations from patient-prepared DMSs were strongly correlated with those of liquid samples (r = 0.996). In a pharmacokinetic study, the median (range) maximum and minimum concentrations were 113 ng/mL (68-205) and 8.5 ng/mL (4.8-13.4), respectively. The milk-to-serum ratio at the trough TCZ concentration of 3 lactating mothers were 0.0015, 0.00082 and 0.0014.

CONCLUSIONS

The DMS method for measuring TCZ transfer into breast milk may be reliable and feasible, and should contribute to evaluating the safety of breast-fed infants whose mothers receive TCZ during lactation.

DHA-enriched re-esterified triacylglycerol fish oil supplementation and oily fish consumption enhance red blood n-3 fatty acid index in Omani pre-adolescent schoolchildren

Dietary habits of Omani population particularly of children and young adults have changed significantly. Consumption of imported calorie-dense foods, vegetable oils, milled and polished grains and carbonated beverages have become the norm. Concomitantly, there has been an exponential increase in the prevalence of non-communicable diseases. The impact of the westernisation of eating habits on children has not been evaluated. We have investigated blood fatty acid profile of male (n = 125) and female (n = 160) children aged 9 and 10 (9.8 ± 0.4) years enrolled from three state-funded schools. The schools, which are homogenous with respect to socio-economic background of their pupils, were randomised into fish oil (n = 98), oily fish (n = 82) or control (n = 105) group. Subsequently, the children were given during morning tea break for 12 weeks: 1. DHA-enriched re-esterified triacylglycerol fish oil capsule with cheese/salad sandwich (fish oil group), 2. Lightly grilled oily fish with salad (fish group) or 3. Cheese/salad sandwich (control group). At baseline, the males had higher myristic, palmitic and oleic and lower adrenic acids than the females (p < 0.05). There was no difference in n-3 fatty acid index (4.86 ± 1.95 vs. 5.12 ± 1.67, p > 0.05) or AA (14.6 ± 1.9 vs. 14.9 ± 1.8, p > 0.05) between the genders. There was no difference in any of the fatty acids between the three groups at baseline. Post-intervention, the oily fish group had lower n-3 fatty acid index (EPA + DHA, 6.03 ± 1.39 vs. 6.60 ± 1.63, p < 0.05) and higher AA (15.2 ± 1.8 vs. 13.7 ± 2.0, p = 0.0001) and n-3 DPA (1.40 ± 0.27 vs. 1.07 ± 0.22, p = 0.0001) compared with those who received fish oil capsules. In both the fish oil and oily fish groups, fatty acid index correlated positively with AA (r = 0.394, p = 0.0001; r = 0.231, p = 0.038) and negatively with total saturated (r = - 0.816, p = 0.0001; r = - 0.439, p = 0.0001) and total mono-unsaturated (r = - 0.431, p = 0.0001; r = - 0.231, p = 0.037) fatty acids. Although seafood is an integral part of traditional Omani cuisine the children had a low level of n-3 fatty acids index. There is a need to address this nutritional insufficiency through school feeding programme, targeted intervention with n-3 fatty acid enriched food products and/or family education programme.

Association of Whole Blood Fatty Acids and Growth in Southern Ghanaian Children 2⁻6 Years of Age

In Ghana, stunting rates in children below 5 years of age vary regionally. Dietary fatty acids (FAs) are crucial for linear growth. The objective of this study was to determine the association between blood FAs and growth parameters in southern Ghanaian children 2⁻6 years of age. A drop of blood was collected on an antioxidant treated card and analyzed for FA composition. Weight and height were measured and z-scores calculated. Relationships between FAs and growth were analyzed by linear regressions and factor analysis. Of the 209 subjects, 22% were stunted and 10.6% were essential FA deficient (triene/tetraene ratio > 0.02). Essential FA did not differ between stunted and non-stunted children and was not associated with height-for-age z-score or weight-for-age z-score. Similarly, no relationships between other blood fatty acids and growth parameters were observed in this population. However, when blood fatty acid levels in these children were compared to previously reported values from northern Ghana, the analysis showed that blood omega-3 FA levels were significantly higher and omega-6 FA levels lower in the southern Ghanaian children (p < 0.001). Fish and seafood consumption in this southern cohort was high and could account for the lower stunting rates observed in these children compared to other regions.

Whole blood n-3 fatty acids are associated with executive function in 2-6-year-old Northern Ghanaian children

Several studies demonstrate the importance of essential fatty acids (EFAs), and the long chain polyunsaturated FA docosahexaenoic acid (DHA), on cognition and brain development. The objective of this study was to investigate the relationship between whole-blood FAs and executive function in children from Northern Ghana. A total of 307, 2-to-6-year-old children attempted the dimensional change card sort (DCCS) task to assess executive function, and dried blood spot samples were collected and analyzed for FA content. Significant differences in mean % total whole-blood fatty acids were observed between children who could not follow directions on the DCCS test (49.8% of the sample) and those who could (50.2% of the sample). Positive associations with DCCS performance were observed for DHA (β=0.25, P=.06), total n-3 (β=0.17, P=.06) and dihomo-gamma-linolenic acid (DGLA; β=0.60, P=.06). Children with the highest levels of total n-3 and DHA were three and four times, respectively, more likely to pass at least one condition of the DCCS test of executive function than those with the lowest DHA levels. The results of this study indicate an association between n-3 FAs and high-level cognitive processes in children two to six years of age, providing impetus for further studies into possible interventions to improve EFA status of children in developing countries.

The role of a FADS1 polymorphism in the association of fatty acid blood levels, BMI and blood pressure in young children-Analyses based on path models

Background

The recent obesity epidemic in children also showed an increase in the prevalence of hypertension. As blood pressure (BP) is associated with (long-chain) polyunsaturated fatty acids (LC PUFA), genetic variation in desaturase enzymes being involved in the synthesis of LC PUFA may be associated with BP. This study aimed to investigate the direct effects (independent of mediating variables) and indirect effects (mediated through intermediate variables) of a common variant in the FADS1 gene, rs174546, known to affect delta-5 desaturase (D5D) activity on PUFA level, body mass index (BMI) and BP.

Methods

A subsample of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) baseline survey including 520 children aged 2 to <10 years from six European countries was included. The association between rs174546 (T<C) and BP z-score as well as the mediating effects of selected key PUFA levels (dihomo-gamma-linolenic acid, DGLA; arachidonic acid, ARA; eicosapentaenoic acid, EPA) or estimated D5D activity (D5D index) and BMI z-score were investigated through path model analyses, adjusting for sex, age, educational level of parents, family history of hypertension, lifestyle factors and blood levels of saturated and monounsaturated fatty acids, triglycerides and low density lipoprotein cholesterol. Whole blood fatty acids were measured by a validated gas chromatographic method and recorded as percentage of weight of all fatty acids detected.

Results

Minor allele carriers of the SNP rs174546 had significantly higher DGLA and lower ARA and EPA levels as well as a lower D5D index. Via ARA and BMI z-score, the polymorphism had an indirect lowering effect on systolic BP z-score for each additional T allele (standardized effect estimate -0.057, p = 0.007). For DGLA, EPA and D5D index, the indirect effects of rs174546 on systolic BP were also negative but did not reach significance. DGLA and EPA had an increasing indirect effect on systolic BP via BMI. Results for diastolic BP were in general similar but effect estimates were lower compared to systolic BP.

Conclusion

Genetic variation in FADS1 influences BP via ARA and BMI indicating a favorable effect of the minor allele in SNP rs174546. Thus, polymorphisms with an impact on the D5D activity may play a role for the BP level mediated through PUFA and BMI. Therefore, health effects of dietary n-6 and n-3 PUFA may vary depending on genetic FADS1 variants.

Heart Rate and Blood Pressure Centile Curves and Distributions by Age of Hospitalized Critically Ill Children

Heart rate (HR) and blood pressure (BP) form the basis for monitoring the physiological state of patients. Although norms have been published for healthy and hospitalized children, little is known about their distributions in critically ill children. The objective of this study was to report the distributions of these basic physiological variables in hospitalized critically ill children. Continuous data from bedside monitors were collected and stored at 5-s intervals from 3,677 subjects aged 0-18 years admitted over a period of 30 months to the pediatric and cardiac intensive care units at a large quaternary children's hospital. Approximately 1.13 billion values served to estimate age-specific distributions for these two basic physiological variables: HR and intra-arterial BP. Centile curves were derived from the sample distributions and compared to common reference ranges. Properties such as kurtosis and skewness of these distributions are described. In comparison to previously published reference ranges, we show that children in these settings exhibit markedly higher HRs than their healthy counterparts or children hospitalized on in-patient wards. We also compared commonly used published estimates of hypotension in children (e.g., the PALS guidelines) to the values we derived from critically ill children. This is a first study reporting the distributions of basic physiological variables in children in the pediatric intensive care settings, and the percentiles derived may serve as useful references for bedside clinicians and clinical trials.

Associations of Whole Blood n-3 and n-6 Polyunsaturated Fatty Acids with Blood Pressure in Children and Adolescents - Results from the IDEFICS/I.Family Cohort

Background

Polyunsaturated n-3 and n-6 polyunsaturated fatty acids (PUFA) are precursors of biologically active metabolites that affect blood pressure (BP) regulation. This study investigated the association of n-3 and n-6 PUFA and BP in children and adolescents.

Methods

In a subsample of 1267 children aged 2–9 years at baseline of the European IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) cohort whole blood fatty acids were measured by a validated gas chromatographic method. Systolic and diastolic BP was measured at baseline and after two and six years. Mixed-effects models were used to assess the associations between fatty acids at baseline and BP z-scores over time adjusting for relevant covariables. Models were further estimated stratified by sex and weight status.

Results

The baseline level of arachidonic acid was positively associated with subsequent systolic BP (β = 0.08, P = 0.002) and diastolic BP (β = 0.07, P<0.001). In thin/normal weight children, baseline alpha-linolenic (β = -1.13, P = 0.003) and eicosapentaenoic acid (β = -0.85, P = 0.003) levels were inversely related to baseline and also to subsequent systolic BP and alpha-linolenic acid to subsequent diastolic BP. In overweight/obese children, baseline eicosapentaenoic acid level was positively associated with baseline diastolic BP (β = 0.54, P = 0.005).

Conclusions

Low blood arachidonic acid levels in the whole sample and high n-3 PUFA levels in thin/normal weight children are associated with lower and therefore healthier BP. The beneficial effects of high n-3 PUFA on BP were not observed in overweight/obese children, suggesting that they may have been overlaid by the unfavorable effects of excess weight.

Extremely preterm infants receiving standard care receive very low levels of arachidonic and docosahexaenoic acids

BACKGROUND & AIMS

Adequate supply of arachidonic (ARA) and docosahexaenoic (DHA) acids is essential for brain development, and extremely preterm infants may be at risk of deficiency. Current levels of ARA and DHA given to extremely preterm infants and the amounts available for accretion have not been established, although recent evidence suggests DHA intake is at a level likely to lead to severe deficits. This study quantified the omega-6 and omega-3 polyunsaturated fatty acid (PUFA) intakes from all sources in the first six weeks of life of preterm infants in standard care. In addition, the relationship between blood levels of circulating cytokines and PUFAs was explored.

METHODS

Single centre longitudinal study with omega-6 and omega-3 PUFA intake data analysed from all sources for 17 infants born <28 weeks gestation. At six weeks of age the infants' whole-blood fatty acid levels were measured along with a range of cytokines and chemokines analysed by Luminex^® multiplex array.

RESULTS

ARA intake was significantly below international recommendations in weeks 1-5 (all p < 0.05), and DHA intake was significantly below recommendations in week 1 (p < 0.0001). The amounts of ARA and DHA available for accretion were significantly below estimated accretion rates in all weeks (all p < 0.001). Mean ARA and DHA intakes were correlated with their respective blood levels (r = 0.568, p = 0.017 and r = 0.704, p = 0.002). There were significant relationships between MIP-1β and blood DHA levels (rs = 0.559, p = 0.02) and between RANTES and omega-6:omega-3 PUFA ratio (rs = -0.498, p = 0.042).

CONCLUSIONS

This study establishes that extremely preterm infants receive insufficient intakes of ARA and DHA. Moreover, blood fatty acid levels may provide a useful measure of intake, where establishing sufficient consumption could have clinical importance. There may also be important interactions between long-chain PUFA status and markers of inflammation, which requires further study.

Blood fatty acid composition in relation to allergy in children aged 2-9 years: results from the European IDEFICS study

BACKGROUND/OBJECTIVES

Blood polyunsaturated fatty acids (PUFA) are involved in allergy development, but the etiological role of n-6 and n-3 PUFA is still controversial. A European multicenter study of children (IDEFICS) provided the opportunity to explore the cross-sectional association between fatty acids (FA) and allergy.

SUBJECTS/METHODS

Blood FA levels were measured in 2600 children aged 2-9 years and were recorded as the percentage of weight of all FA detected. Logistic regression of allergy status on FA components was adjusted for age, sex, country, body mass index, family history of allergic disease, breast-feeding, and number of siblings. The results were given as odds ratios (OR) for current vs no allergy ever and an increase in FA by 1 s.d.

RESULTS

Overall, higher proportions of n-6 PUFA were associated with higher odds of allergy (OR=1.21 (1.05, 1.40)). Monounsaturated FA (MUFA) were associated with reduced risk for allergy (OR=0.75 (0.65, 0.87)), whereas saturated FA did not differ by allergy status. The strongest associations were observed in children <4 years old, with ORs of allergy given as 1.62 (1.15, 2.29) for n-3 PUFA and 0.63 (0.42, 0.95) for MUFA. With regard to individual FA, these associations were independently observed for docosapentaenoic acid (22:5 n-3) and oleic acid (18:1 n-9).

CONCLUSIONS

Both PUFA subtypes were positively associated with allergy in an age-dependent manner, whereas MUFA was associated with less allergy. The observation of high proportions of n-3 PUFA in allergic children younger than 4 years might help to understand the nature of early onset of atopic disease.

Dried blood spot omega-3 and omega-6 long chain polyunsaturated fatty acid levels in 7-9 year old Zimbabwean children: a cross sectional study

BACKGROUND

Omega-3 long chain-polyunsaturated fatty acids (LC-PUFAs)-docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and eicosapentaenoic acid (EPA)- and omega-6 LC-PUFA arachidonic acid (ARA), are essential for optimum physical and mental development in children. Prior to this study, the blood omega-3 LC-PUFA levels were unknown in Zimbabwean children, particularly in those aged 7-9 years, despite the documented benefits of LC-PUFAs. Documentation of the LC-PUFA levels in this age group would help determine whether interventions, such as fortification, are necessary. This study aimed to determine dried whole blood spot omega-3 and omega-6 LC-PUFA levels and LC-PUFA reference intervals among a selected group of Zimbabwean children aged 7-9 years old.

METHODS

We conducted a cross sectional study from September 2011 to August 2012 on a cohort of peri-urban, Zimbabwean children aged 7-9 years. The children were born to mothers enrolled at late pregnancy into an HIV prevention program between 2002 and 2004. Dried whole blood spots were sampled on butylated hydroxytoluene antioxidant impregnated filter papers and dried. LC-PUFAs were quantified using gas liquid chromatography. Differences in LC-PUFAs between groups were compared using the Kruskal Wallis test and reference intervals determined using non-parametric statistical methods.

RESULTS

LC-PUFAs levels were determined in 297 Zimbabwean children of whom 170 (57.2 %) were girls. The study determined that LC-PUFAs (wt/wt) ranges were EPA 0.06-0.55 %, DPA 0.38-1.98 %, DHA 1.13-3.52 %, ARA 5.58-14.64 % and ARA: EPA ratio 15.47-1633.33. Sixteen participants had omega-3 LC-PUFAs levels below the determined reference intervals, while 18 had higher omega-6 LC-PUFAs. The study did not show gender differences in omega-3 and omega-6 LC-PUFAs levels (all p > 0.05). EPA was significantly higher in the 8 year age group compared to those aged 7 and 9 years (median; 0.20 vs 0.17 vs 0.18, respectively, p = 0.049). ARA: EPA ratio was significantly higher in the 7 year age group compared to those aged 8 and 9 years (median; 64.38 vs 56.43 vs 55.87 respectively, p = 0.014).

CONCLUSIONS

In this cohort of children, lower EPA levels and higher ARA: EPA ratios were observed compared to those reported in apparently healthy children elsewhere. The high ARA: EPA ratios might increase the vulnerability of these children to inflammatory pathologies. Identification and incorporation into diet of locally produced foodstuffs rich in omega-3 LC-PUFAs is recommended as well as advocating for dietary supplementation with omega-3 fish oils and algae based oils.

Whole Blood Levels of the n-6 Essential Fatty Acid Linoleic Acid Are Inversely Associated with Stunting in 2-to-6 Year Old Tanzanian Children: A Cross-Sectional Study

BACKGROUND

In Tanzania, 35% of all children below five years of age are stunted. Dietary fatty acids (FA) are critical for growth and development. However, whole blood FA levels in Tanzanian children are poorly described.

OBJECTIVE

The objectives of this cross-sectional study were to assess 1) whole blood levels of essential fatty acids and 2) the association between whole blood FA levels and growth parameters in Tanzanian children 2-6 years of age.

METHODS

A drop of blood was collected on an antioxidant treated card and analyzed for FA composition. Weight and height were measured and z-scores calculated. Relationships between FAs and growth parameters were analyzed by linear regression.

RESULTS

Of the 334 children that participated, 30.3% were stunted. The average whole blood level of Mead acid was 0.15%. The anthropometric z-score height-for-age (HAZ) was inversely associated with Mead acid, the Mead acid to arachidonic acid (T/T) ratio, and total n-9 FA. Additionally, HAZ was positively associated with linoleic acid and total n-6 FA. BMI-for-age was positively associated with oleic acid, total n-9 FA and T/T ratio but inversely associated with arachidonic acid and total n-6 FA. Weight-for-height was inversely associated with arachidonic acid and total n-6 FAs and positively associated with oleic acid and total n-9 FA. Weight-for-age was not associated with any FA tested. Total n-3 FAs were not associated with any growth parameters measured.

CONCLUSIONS

The EFA linoleic acid and the markers of FA deficiency were associated with HAZ, an indicator for stunting in 2-6 year old Tanzanian children. Total n-6, total n-9, and a number of individual FAs were associated with growth. Increasing dietary intake of EFA and n-6 FAs may be a strategy to combat stunting in this population.

Analysis of breast milk fatty acid composition using dried milk samples

Background

The effect of breast milk fatty acid (FA) composition, particularly levels of docosahexaenoic acid (DHA), on infant health outcomes is unclear. Part of the reason for this is difficulties in collecting, storing and shipping milk samples to the laboratory. Here we report the validation of a dried milk spot (DMS) system to measure FA composition to help overcome these obstacles.

Milk FA were measured by gas chromatography and reported as percent of total FA; the FA of primary interest in this study were DHA and industrially produced trans FA (iTFA). Experiments were carried out using pooled milk samples from US (n = 5) and Malawian women (n = 50). Experiments compared liquid vs. DMS samples (n = 55), assessed stability of FA composition under different storage conditions (n = 5), and compared the results from two different labs using the same methods (n = 5).

Results

Both % DHA and % iTFA levels in liquid and DMS samples were strongly correlated (R² = 0.99 and 0.99, respectively, P < 0.0001). The % DHA in DMS samples was stable for up to four weeks at room temperature and up to three years at -80 °C; only slight deviations from the acceptable range of variability (±15 %) occurred in the 4 °C and -20 °C conditions for % DHA. The % iTFA was stable under all conditions. All % DHA and % iTFA were within 15 % of the referent when analyzed in two laboratories.

Conclusions

Valid FA composition values can be obtained from DMS samples using this robust collection and transport system which should facilitate studies of the role of milk FA composition in infant development.

Electronic supplementary material

The online version of this article (doi:10.1186/s13006-016-0060-2) contains supplementary material, which is available to authorized users.

DHA Effects in Brain Development and Function

Docosahexaenoic acid (DHA) is a structural constituent of membranes specifically in the central nervous system. Its accumulation in the fetal brain takes place mainly during the last trimester of pregnancy and continues at very high rates up to the end of the second year of life. Since the endogenous formation of DHA seems to be relatively low, DHA intake may contribute to optimal conditions for brain development. We performed a narrative review on research on the associations between DHA levels and brain development and function throughout the lifespan. Data from cell and animal studies justify the indication of DHA in relation to brain function for neuronal cell growth and differentiation as well as in relation to neuronal signaling. Most data from human studies concern the contribution of DHA to optimal visual acuity development. Accumulating data indicate that DHA may have effects on the brain in infancy, and recent studies indicate that the effect of DHA may depend on gender and genotype of genes involved in the endogenous synthesis of DHA. While DHA levels may affect early development, potential effects are also increasingly recognized during childhood and adult life, suggesting a role of DHA in cognitive decline and in relation to major psychiatric disorders.

The stability of blood fatty acids during storage and potential mechanisms of degradation: A review

Fatty acids in blood samples, particularly polyunsaturated fatty acids (PUFAs), are susceptible to degradation through peroxidation reactions during long-term storage. Storage of blood samples is necessary in almost all studies and is crucial for larger clinical studies and in field research settings where it is not plausible for analytical infrastructure. Despite this, PUFA stability during blood storage is often overlooked. This review introduces and discusses lipid peroxidation and popular strategies employed to prevent or minimize peroxidation reactions during fatty acid analysis. Further, an in-depth examination of fatty acid stability during storage of blood is discussed in detail for all blood fractions including plasma/serum, erythrocytes and whole blood stored both in cryovials and on chromatography paper before discussing the associated mechanisms of degradation during storage. To our knowledge this is the first review of its kind and will provide researchers with the necessary information to confidently store blood samples for fatty acid analysis.

Desaturase Activity Is Associated With Weight Status and Metabolic Risk Markers in Young Children

CONTEXT

Activity of delta-9, delta-6, and delta-5 desaturases (D9D, D6D, D5D) are associated with obesity, insulin resistance, and dyslipidemia.

OBJECTIVE

To investigate the association of estimated desaturase activities with weight status, insulin resistance, and dyslipidemia in children, cross-sectionally and longitudinally.

DESIGN

The IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants) cohort study was used, with examinations at baseline (T0) and after 2 years (T1).

SETTING AND PARTICIPANTS

Children aged 2 to less than 10 years from eight European countries were recruited in kindergartens/primary schools. Children with available data on fatty acids, outcome, and covariate information were included in the analyses.

METHODS

Whole blood fatty acids were analyzed in 2600 children at baseline. D9D (16:1n-7/16:0), D6D (20:3n-6/18:2n-6), and D5D (20:4n-6/20:3n-6) activities were estimated from product-precursor fatty acids ratios. Body mass index (BMI), Homeostatic Model Assessment index, and high-density lipoprotein cholesterol (HDL), and triglycerides (TG) served as outcomes for weight status, insulin resistance, and dyslipidemia, respectively. Linear and logistic regression and repeated measures models were used to assess the cross-sectional and longitudinal associations between desaturase activity and outcomes.

RESULTS

In the cross-sectional analysis, D9D and D6D were positively associated with BMI and TG z-scores and inversely with HDL z-scores. D5D was inversely associated with BMI and TG z-scores (ie, a D5D increase of 1 unit is associated with a BMI z-score decrease of 0.07 and a 28% lower odds ratio for TG ≥ 75th percentile). Longitudinally, similar associations were found for T0 desaturase activities with BMI and for T0 D6D with HDL at follow-up (T1). Baseline D6D and D5D were positively associated with the change of HDL z-score from T0 to T1, and D6D with the change of Homeostatic Model Assessment index z-score.

CONCLUSION

Desaturase activities are associated with metabolic risk markers already in young children and appear to predict the metabolic risk.