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Introduction: Patients with phenylketonuria (PKU) must follow a lifelong phenylalanine (Phe)-restricted diet with additional amino acid supplementations, and this may put them at risk for nutritional disturbances. However, the body composition and nutritional status of adult patients with PKU has only been partially explored. The current study aims to assess the body composition of adult patients with PKU using multifrequency bioimpedance analysis (MF-BIA) and to reveal potential correlations between therapy adherence and body composition. Additionally, we compared body composition of patients with healthy controls. Methods: Fifty adult patients with early-treated PKU (27 female and 23 male) and 40 healthy, age- and gender-matched controls were included in this single-center, cross-sectional study. MF-BIA was performed on all subjects. Additionally, we determined serum nutritional markers for all patients. In the PKU patient group, correlation analyses were performed between body composition parameters and therapy adherence. We compared body composition of patients with PKU and controls using BIA. Results: The proportion of overweight was 56% among all patients with PKU. Female patients with PKU had significantly higher body fat percentage compared with controls. In parallel with higher fat content, we observed lower muscle mass, protein, and mineral content among female patients with PKU compared to controls. Such findings were not observed in male patients. Female patients with PKU had decreased therapy adherence and had significantly lower prealbumin levels compared with males. There was no significant correlation observed between body composition parameters and therapy adherence over the last 10 years in the PKU patient group. Conclusion: Although female patients had less optimal therapy adherence over the last 10 years compared with male patients, our results suggest that this does not influence body composition fundamentally. Our results suggest that obesity is an important comorbidity in young adult patients with PKU, especially in females. We advocate that nutritional assessments and weight management should be additional objectives of PKU management to provide optimal care. [ABSTRACT FROM AUTHOR]

Glutamate (Glu) is the most abundant amino acid (AA) in human milk. Available information on Glu supply and metabolism was reviewed, based on an electronic literature search. In 22 cross-sectional global studies with 4,747 women, free Glu increases with lactation duration and contributes to about 38% of total and 63% of dispensable milk AA. Based on these data, a typical breastfed infant obtains a mean free Glu intake of 35.7 mg/kg body weight (bw; upper end of the normal range 134.6 mg/kg), while precisely collected longitudinal data indicate mean intakes of 40 mg/kg and upper range intakes of 70.2 mg/kg. Mean intakes with cows' milk formula at median concentrations are 0.7 mg/kg (upper range 1.0 mg/kg) and with extensive protein hydrolysate formula 171.7 mg/kg bw (upper range 249.8 mg/kg bw), with no indication of untoward effects. Infants almost entirely utilize dietary Glu in splanchnic organs, with no appreciable effect on plasma Glu concentrations. Estimated free Glu intakes in breastfed infants are up to 4.5-fold higher than the acceptable daily intake (ADI) set by the European Food Safety Authority for the total population including infants, and the respective intakes of infants fed a formula based on an extensive protein hydrolysate are up to 8.3-fold higher. There is no reason to assume that feeding human milk or an extensive protein hydrolysate infant formula would be unsuitable or unsafe for infants. Setting an ADI below the range of the normal intake with a safe diet in generally healthy individuals, that is, below 250 mg/kg per day, seems inappropriate. [ABSTRACT FROM AUTHOR]

Background: Adult phenylketonuria (PKU) patients often reduce their intake of amino acid mixture (AAM) to less than the prescribed amounts. Effects of reduced AAM intake on nutrient supply were evaluated. Methods: Nutrient intake was calculated in 20 adult PKU patients based on a structured food record and complemented by laboratory assessment of nutritional status. Patients were classified into 2 groups, (A) regular AAM intake, or (B) AAM intake below calculated requirements. Results: Group B consumed a higher proportion of natural protein (60 ± 23 vs. 33 ± 12%, p = 0.002); however, the total protein intake was below the recommended amounts in 60% of patients in group B versus 7% in group A ( p = 0.03). Fat intake was higher in group B (39 ± 9% of energy vs. 31 ± 6%, p = 0.03), mainly from saturated fats. Selenium, folate, and vitamin B12 intake was below the recommended intake in group B. However, serum concentrations of these analytes remained within the normal range in both groups, although vitamin B12 levels were lower in group B. Plasma tyrosine correlated with AAM intake, and hydroxyproline correlated with the amount of natural protein consumed. Conclusion: Relaxed AAM intake resulted in insufficient nutrient supply, despite a compensatory increase in consumption of natural protein. Care needs to be taken to ensure adequate nutrition in adults with PKU. [ABSTRACT FROM AUTHOR]

Human milk lipids provide the infant with energy and essential vitamins, polyunsaturated fatty acids, and bioactive components. Adding complex lipids and milk fat globule membranes to vegetable oil-based infant formula has the potential to enhance infant development and reduce infections. Cholesterol provision with breastfeeding modulates infant sterol metabolism and may induce long-term benefits. Some 98-99% of milk lipids are comprised by triacylglycerols, whose properties depend on incorporated fatty acids. Attention has been devoted to the roles of the longchain polyunsaturated fatty acids docosahexaenoic (DHA) and arachidonic (ARA) acids. Recent studies on gene-diet interaction (Mendelian randomization) show that breastfeeding providing DHA and ARA improves cognitive development and reduces asthma risk at school age particularly in those children with a genetically determined lower activity of DHA and ARA synthesis. It appears prudent to follow the biological model of human milk in the design of infant formula as far as feasible, unless conclusive evidence for the suitability and safety of other choices is available. The recent European Union legislative stipulation of a high formula DHA content without required ARA deviates from this concept, and such a novel formula composition has not been adequately evaluated. Great future opportunities arise with significant methodological progress for example in lipidomic analyses and their bioinformatic evaluation, which should enhance understanding of the biology of human milk lipids. Such knowledge might lead to improved dietary advice to lactating mothers as well as to further opportunities to enhance infant formula composition. [ABSTRACT FROM AUTHOR]

Human milk lipids provide the infant with energy and essential vitamins, polyunsaturated fatty acids, and bioactive components. Adding complex lipids and milk fat globule membranes to vegetable oil-based infant formula has the potential to enhance infant development and reduce infections. Cholesterol provision with breastfeeding modulates infant sterol metabolism and may induce long-term benefits. Some 98-99% of milk lipids are comprised by triacylglycerols, whose properties depend on incorporated fatty acids. Attention has been devoted to the roles of the long-chain polyunsaturated fatty acids docosahexaenoic (DHA) and arachidonic (ARA) acids. Recent studies on gene-diet interaction (Mendelian randomization) show that breastfeeding providing DHA and ARA improves cognitive development and reduces asthma risk at school age particularly in those children with a genetically determined lower activity of DHA and ARA synthesis. It appears prudent to follow the biological model of human milk in the design of infant formula as far as feasible, unless conclusive evidence for the suitability and safety of other choices is available. The recent European Union legislative stipulation of a high formula DHA content without required ARA deviates from this concept, and such a novel formula composition has not been adequately evaluated. Great future opportunities arise with significant methodological progress for example in lipidomic analyses and their bioinformatic evaluation, which should enhance understanding of the biology of human milk lipids. Such knowledge might lead to improved dietary advice to lactating mothers as well as to further opportunities to enhance infant formula composition. [ABSTRACT FROM AUTHOR]

Background: Severe intellectual disability and growth impairment have been overcome by the success of early and continuous treatment of patients with phenylketonuria (PKU). However, there are some reports of obesity, particularly in women, suggesting that this may be an important comorbidity in PKU. It is becoming evident that in addition to acceptable blood phenylalanine control, metabolic dieticians should regard weight management as part of routine clinical practice. Summary: It is important for practitioners to differentiate the 3 levels for overweight interpretation: anthropometry, body composition and frequency and severity of associated metabolic comorbidities. The main objectives of this review are to suggest proposals for the minimal standard and gold standard for the assessment of weight management in PKU. While the former aims to underline the importance of nutritional status evaluation in every specialized clinic, the second objective is important in establishing an understanding of the breadth of overweight and obesity in PKU in Europe. Key Messages: In PKU, the importance of adopting a European nutritional management strategy on weight management is highlighted in order to optimize long-term health outcomes in patients with PKU. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: In phenylketonuria (PKU), phenylalanine-free L-amino acid supplements are the major source of dietary micronutrients. Methods: Four hundred fifty-two retrospective annual/bi-annual non-fasting blood samples for nutritional markers (plasma zinc, selenium, and serum folate) from 78 subjects aged 1-16 years (median number of blood samples: 6, range 1-14) were analysed over 12 years. Longitudinal blood result data were available for 51 subjects (65%). The dietary intake from supplements was calculated. Results: The median intakes of all of the micronutrients studied were >200% of the reference nutrient intakes (RNI). There was no statistical correlation between dietary intake and nutritional markers outside of the normal reference range (RR) except for selenium, but there was a correlation between a lower plasma zinc, plasma selenium and haemoglobin status and better blood phenylalanine control in 1- to 4-year-old children. On at least one occasion, the individual plasma concentrations of zinc (71%, n = 54/76) and selenium (21%, n = 16/75) were below the RR; however, the concentrations of selenium (41%, n = 31/75) and serum folate (83%, n = 34/41) were also above the RR. Dietary intakes exceeded the upper tolerable intakes for zinc and copper (32%, n = 25) and folate (65%, n = 51). Individual longitudinal data demonstrated little change in micronutrient status over time. Conclusions: In PKU, biochemical micronutrient deficiencies are common despite micronutrient intakes above the RNI. Further study of the nutritional profiling of L-amino acid supplements in PKU is needed. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: C4 plants (e.g. corn and sugar cane) have greater 13C enrichment than C3 plants (e.g. wheat and sugar beet). Objective: To assess whether 13C enrichment of CO2 in the breath and breast milk of women on diets based on C3 and C4 foods changes from one diet to the other. Materials and Methods: Six breast-feeding women were studied at 5-6 months postpartum. They ate a controlled C4 diet on days 1 and 2 followed by a C3 diet on days 3 and 4. Diet duplicates, breast milk on days 2 and 4 and hourly breath samples were collected over 4 days. 13C enrichment was measured by isotope-ratio mass spectrometry. Values of δ13C were calculated from the international PDBV standard (δ13CPDBV). Differences between means were compared by paired t test or t test for repeated measurements. Results: δ13CPDBV values were significantly higher in the C4 diet than in the C3 diet composites (p < 0.01). In breath CO2, the δ13CPDBV value was greater on days 1 and 2 (range -15.4 to -13.2, respectively) and declined on days 3 and 4 (range -20.0 to -21.8, respectively, p < 0.01). The lipid and milk serum fractions of breast milk had significantly higher δ13CPDBV on the C3 diet than on the C4 diet (p < 0.01). Conclusions: Subjects eating a C4 diet have a higher δ13CPDBV value in the breath and breast milk fractions, which diminish rapidly on a C3 diet. Further studies focusing on individual nutrients are warranted. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Phenylketonuria (PKU) is caused by a severe phenylalanine hydroxylase deficiency; the mainstay of treatment is a low-phenylalanine diet. A diet which is so restrictive is associated with a risk of nutritional deficiencies. We investigated plasma concentrations for 46 elements, including minerals and trace elements. Methods: We enrolled 20 children and adolescents with PKU and 20 matched controls. Multi-elementary quantification was carried out by solution-based inductively coupled plasma atomic emission spectroscopy (ICP-AES) and ICP mass spectrometry (ICP-MS). Results: With the exception of manganese and aluminium, no significant differences were found for element levels between PKU patients and controls. As a trend, manganese levels were lower in PKU patients than in control subjects (p < 0.05) but were within the reference range. There was a positive linear relationship between manganese and tyrosine levels in subjects with PKU (r2 = 0.2295, p < 0.05). If detectable, potentially toxic elements were only identified in ultra-trace quantities in plasma samples of either group; aluminium levels were found to be slightly higher in PKU subjects than in controls (p < 0.01). Conclusion: The combination of ICP-AES and ICP-MS data is a useful diagnostic tool for element quantification at a high analytical rate and for monitoring bio-element status, e.g. in patients on a restrictive diet. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Common inborn errors of metabolism treated by low natural protein diets [amino acid (AA) disorders, organic acidemias and urea cycle disorders] are responsible for a collection of diverse clinical symptoms, each condition presenting at different ages with variable severity. Precursor-free or essential l-AAs are important in all these conditions. Optimal long-term outcome depends on early diagnosis and good metabolic control, but because of the rarity and severity of conditions, randomized controlled trials are scarce. In all of these disorders, it is commonly described that dietary adherence deteriorates from the age of 10 years onwards, at least in part representing the transition of responsibility from the principal caregivers to the patients. However, patients may have particular difficulties in managing the complexity of their treatment because of the impact of the condition on their neuropsychological profile. There are little data about their ability to self-manage their own diet or the success of any formal educational programs that may have been implemented. Trials conducted in non-phenylketonuria (PKU) patients are rare, and the development of specialist l-AAs for non-PKU AA disorders has usually shadowed that of PKU. There remains much work to be done in refining dietary treatments for all conditions and gaining acceptable dietary adherence and concordance, which is crucial for an optimal outcome. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background/Aims: Fatty acid (FA) composition varies over the course of the day and during lactation. The aim of this study was to evaluate FA composition and its compositional stability in human milk, from day 7 to week 16 of lactation. Methods: Human milk was collected from all feedings over 24 h at day 7 and weeks 4, 8, 12 and 16 of lactation in 31 lactating women. FAs were analyzed through gas chromatography. Comparisons were made with analysis of variance. Results: Total monounsaturated FAs decreased from 33.04 ± 2.58% wt/wt at day 7 to 31.48 ± 3.32% wt/wt at week 16 of lactation, much at the expenses of the decrease in the major monounsaturated FA found in human milk, oleic acid. Main polyunsaturated FAs n-6 and n-3 showed fluctuations from day 7 up to week 16 of lactation, but with no statistical significance. Arachidonic acid significantly decreased from transitional to mature milk. Conclusions: The FA profile obtained throughout the study time points presented very low levels of oleic acid and very high linoleic acid/α-linoleic acid ratios which reflect recent changes in Portuguese women’s food patterns. Despite this, the ascorbate/dehydroascorbate ratio remained constant during the study, suggesting a protective metabolic mechanism. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Adults and children in Mediterranean countries are believed to consume a Mediterranean-type diet which is higher in monounsaturated and n–3 polyunsaturated fatty acids than compared to central and northern parts of Europe and has preventive effects for cardiovascular risks. Subjects and Methods: In preschool children from Porto, Portugal (n = 35) and Munich, Germany (n = 18) we determined the plasma phospholipid fatty acid composition considered as a biomarker for dietary fat intake. Results: The plasma phospholipid contents of total saturated fatty acids are similar in both groups, but the Portuguese children have lower values of monounsaturated and n–3 polyunsaturated fatty acids. The results indicate that the food habits of Portuguese children are even less close to the traditional Mediterranean diet than those of German children. Conclusions: Efforts should be made to encourage young families as well as manufacturers and distributors of food products in Portugal to emphasize traditional Mediterranean food habits, especially in young children.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The fatty acid composition of human colostrum lipids is influenced by maternal diet. We measured the fatty acid composition of colostrum lipids in Slovenia. Methods: Milk samples were collected on the 3rd day postpartum from 41 women recruited in three Slovenian regions (Celje, Ljubljana and Koper). Dietary habits were examined by a food-frequency questionnaire. In situ transesterification and capillary gas chromatography were performed to determine the fatty acid composition. Results: The coefficients of variation of the determinations of individual fatty acids accounting for >0.09 wt% were 1.87–5.91%. Between regional areas there were differences in the contents of linoleic (12.62–17.35 wt%; p < 0.001) and α-linolenic acid (0.70–1.07 wt%; p < 0.01), whereas the linoleic/α-linolenic acid ratios were similar (15.8 in Celje, 16.3 in Ljubljana and 17.9 in Koper). The highest proportion of docosahexaenoic acid (C22:6n–3) was in Celje (0.49 wt%), the lowest in Ljubljana (0.35 wt%; p < 0.05). The long-chain polyunsaturated fatty acid (LCP) content did not correlate with linoleic and α-linolenic acid, but there was a correlation between the sum of n–3 and n–6 LCPs. The colostrum linoleic/α-linolenic acid ratio was positively correlated with the body mass index during pregnancy. Conclusions: The fatty acid composition of colostrum lipids in Slovenia shows some variation according to geographical regions.Copyright © 2000 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: We studied the oxidation of an oil rich in docosahexaenoic acid (DHA; DHASCO[sup ®] ) in lactating mothers receiving a dietary DHA supplement or a placebo. The results were compared with the oxidation of linoleic acid. Methods: Breast-feeding mothers received a dietary supplement (DHASCO; 200 mg DHA/day, n = 5) or a placebo (n = 5) for 14 days. Six weeks post partum all 10 mothers received a single dose of 2 mg/kg body weight uniformly [sup 13] C-labeled DHASCO. In a previously reported study 6 mothers received 1 mg/kg body weight uniformly [sup 13] C-labeled linoleic acid. Breath samples were collected over 48 h after tracer application. The total CO[sub 2] production was measured by indirect calorimetry and the [sup 13] C isotopic enrichment of labeled CO[sub 2] by isotopic ratio mass spectrometry. Results: The oxidation of [sup 13] C-labeled DHASCO in the supplemented and placebo groups was similar. Maximal [sup 13] C enrichment was reached earlier in the group receiving [sup 13] C-DHASCO (median 1.0 vs. 3.0 h in the linoleic acid group). The cumulative [sup 13] C recovery in breath was higher in the DHASCO versus the linoleic acid group until 10 h after tracer application and comparable thereafter. Conclusions: The difference in oxidation of DHASCO versus linoleic acid after tracer ingestion might be partly due to a faster absorption and oxidation of shorter chain saturated fatty acids contained in DHASCO. The cumulative oxidation of DHASCO and linoleic acid 24 and 48 h after tracer ingestion is similar.Copyright © 2000 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]