Postprandial changes of amino acid and acylcarnitine concentrations in dried blood samples

Fingerhut, Ralph; Arevalo, Gabriel De Jesus Silva; Baumgartner, Matthias R.; Häberle, Johannes; Rohrbach, Marianne; Figueroa, Andrés Weinfeld Ávalos; Fresse, Elena María Dardón; Polanco, Olga Leticia; Torresani, Toni

doi:10.1007/s10545-010-9167-6

Cited by 4 publications

(6 citation statements)

References 13 publications

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“…Histidine levels are used for the diagnosis of histidinemia and formiminotransferase deficiency [131]. Further complicating correct diagnoses is the fact that many amino acid biomarkers may be affected by other factors such as feeding prior to screening or day time of screening [124,132].…”

Section: Targeted Metabolomics In the Screening And Diagnosis Of mentioning

confidence: 99%

Inborn Errors of Metabolism in the Era of Untargeted Metabolomics and Lipidomics

2019

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Inborn errors of metabolism (IEMs) are a group of inherited diseases with variable incidences. IEMs are caused by disrupting enzyme activities in specific metabolic pathways by genetic mutations, either directly or indirectly by cofactor deficiencies, causing altered levels of compounds associated with these pathways. While IEMs may present with multiple overlapping symptoms and metabolites, early and accurate diagnosis of IEMs is critical for the long-term health of affected subjects. The prevalence of IEMs differs between countries, likely because different IEM classifications and IEM screening methods are used. Currently, newborn screening programs exclusively use targeted metabolic assays that focus on limited panels of compounds for selected IEM diseases. Such targeted approaches face the problem of false negative and false positive diagnoses that could be overcome if metabolic screening adopted analyses of a broader range of analytes. Hence, we here review the prospects of using untargeted metabolomics for IEM screening. Untargeted metabolomics and lipidomics do not rely on predefined target lists and can detect as many metabolites as possible in a sample, allowing to screen for many metabolic pathways simultaneously. Examples are given for nontargeted analyses of IEMs, and prospects and limitations of different metabolomics methods are discussed. We conclude that dedicated studies are needed to compare accuracy and robustness of targeted and untargeted methods with respect to widening the scope of IEM diagnostics.

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Section: Targeted Metabolomics In the Screening And Diagnosis Of mentioning

confidence: 99%

Inborn Errors of Metabolism in the Era of Untargeted Metabolomics and Lipidomics

2019

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“…In healthy individuals Phe and Tyr concentrations rise significantly after meals [23]. Fingerhut et al studied amino acid concentrations in dried blood spots of 92 probands (< 1 to 48 years) and found postprandial increases of Phe and Tyr concentrations of 18% and 14%, respectively [23].…”

Section: Discussionmentioning

confidence: 99%

Diurnal variation of phenylalanine and tyrosine concentrations in adult patients with phenylketonuria: subcutaneous microdialysis is no adequate tool for the determination of amino acid concentrations

Grünert

Brichta

Krebs

et al. 2013

Nutr J

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BackgroundMetabolic control and dietary management of patients with phenylketonuria (PKU) are based on single blood samples obtained at variable intervals. Sampling conditions are often not well-specified and intermittent variation of phenylalanine concentrations between two measurements remains unknown. We determined phenylalanine and tyrosine concentrations in blood over 24 hours. Additionally, the impact of food intake and physical exercise on phenylalanine and tyrosine concentrations was examined. Subcutaneous microdialysis was evaluated as a tool for monitoring phenylalanine and tyrosine concentrations in PKU patients.MethodsPhenylalanine and tyrosine concentrations of eight adult patients with PKU were determined at 60 minute intervals in serum, dried blood and subcutaneous microdialysate and additionally every 30 minutes postprandially in subcutaneous microdialysate. During the study period of 24 hours individually tailored meals with defined phenylalanine and tyrosine contents were served at fixed times and 20 min bicycle-ergometry was performed.ResultsSerum phenylalanine concentrations showed only minor variations while tyrosine concentrations varied significantly more over the 24-hour period. Food intake within the patients’ individual diet had no consistent effect on the mean phenylalanine concentration but the tyrosine concentration increased up to 300% individually. Mean phenylalanine concentration remained stable after short-term bicycle-exercise whereas mean tyrosine concentration declined significantly. Phenylalanine and tyrosine concentrations in dried blood were significantly lower than serum concentrations. No close correlation has been found between serum and microdialysis fluid for phenylalanine and tyrosine concentrations.ConclusionsSlight diurnal variation of phenylalanine concentrations in serum implicates that a single blood sample does reliably reflect the metabolic control in this group of adult patients. Phenylalanine concentrations determined by subcutaneous microdialysis do not correlate with the patients’ phenylalanine concentrations in serum/blood.

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“…Term and preterm infants fed breast milk or formula with different protein concentrations experience an increase in the total concentration of AA, depending on protein concentration received [ 3 , 4 ]. Plasma levels of essential AA are also higher in formula-fed infants compared to breast-fed infants [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

“…In healthy individuals the intra-individual coefficient of variation for essential AA is lower than for non-essential AA, suggesting a tighter homeostatic control for essential AA. Specifically, the average concentration of phenylalanine (Phe) in plasma is 63 μmol/L, with an intra-individual coefficient of variation of 9.5% [ 5 ], with the variation in AA ranging from 12–32% [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

Highest Plasma Phenylalanine Levels in (Very) Premature Infants on Intravenous Feeding; A Need for Concern

et al. 2015

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ObjectiveTo analyse the association in newborns between blood levels of phenylalanine and feeding method and gestational age.Study DesignThis observational, cross-sectional study included a sample of 11,829 infants between 2008 and 2013 in a Spanish region. Data were recorded on phenylalanine values, feeding method [breast, formula, mixed (breast plus formula), or partial or fully intravenous feeding], gestational age in weeks (<32, 32–37, ≥37), gender and days since birth at the moment of blood collection. Outcomes were [phenylalanine] and [phenylalanine] ≥95th percentile. Associations were analysed using multivariate models [linear (means difference) and logistic regression (adjusted odds ratios)].ResultsHigher phenylalanine values were associated with lower gestational age (p<0.001) and with intravenous feeding (p<0.001).ConclusionThe degree of prematurity and intravenous feeding influenced the plasma concentration of phenylalanine in the newborn. Caution should be taken in [phenylalanine] for newborns with intravenous feeding, monitoring them carefully. Very preterm infants given the recommended amount of amino acids should also be strictly monitored. These findings should be taken into consideration and call for adapting the amounts to the needs of the infant.

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Postprandial changes of amino acid and acylcarnitine concentrations in dried blood samples

Cited by 4 publications

References 13 publications

Inborn Errors of Metabolism in the Era of Untargeted Metabolomics and Lipidomics

Inborn Errors of Metabolism in the Era of Untargeted Metabolomics and Lipidomics

Diurnal variation of phenylalanine and tyrosine concentrations in adult patients with phenylketonuria: subcutaneous microdialysis is no adequate tool for the determination of amino acid concentrations

Highest Plasma Phenylalanine Levels in (Very) Premature Infants on Intravenous Feeding; A Need for Concern

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