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Rocha JC, Hermida Á, Jones CJ, Wu Y, Clague GE, Rose S, Whitehall KB, Ahring KK, Pessoa ALS, Harding CO, Rohr F, Inwood A, Longo N, Muntau AC, Sivri S, Maillot F. Meta-analysis of bone mineral density in adults with phenylketonuria. Orphanet J Rare Dis 2024; 19:338. [PMID: 39267130 PMCID: PMC11391789 DOI: 10.1186/s13023-024-03223-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 05/19/2024] [Indexed: 09/14/2024] Open
Abstract
BACKGROUND Lifelong management of phenylketonuria (PKU) centers on medical nutrition therapy, including dietary phenylalanine (Phe) restriction in addition to Phe-free or low-Phe medical foods/protein substitutes. Studies have reported low bone mineral density (BMD) in mixed-age PKU populations, possibly related to long-term Phe restriction. Therefore, a meta-analysis investigating BMD specifically in adults with PKU was conducted. METHODS Studies reporting BMD-related outcomes were identified from a systematic literature review evaluating somatic comorbidities experienced by adults with PKU on a Phe-restricted diet (searched February 1, 2022, updated November 1, 2023). Risk of study bias was assessed (Scottish Intercollegiate Guidelines Network checklists). The primary outcome of the meta-analysis was pooled mean BMD Z-scores of different bones. Secondary outcomes were the prevalence of low BMD Z-scores at pre-specified thresholds. Subgroup analyses of mean BMD Z-scores (decade of study publication, controlled versus uncontrolled blood Phe levels, gender) were conducted. RESULTS BMD-related data from 4097 individuals across 10 studies rated as at least acceptable quality were included. Mean BMD Z-scores were statistically significantly lower compared with an age-matched control or reference (non-PKU) population, across bones, but still within the expected range for age (> -2.0): lumbar spine (seven studies, n = 304), -0.63 (95% confidence interval (CI): -0.74, -0.52); femoral neck (four studies, n = 170), -0.74 (95% CI: -1.25, -0.22); radius (three studies, n = 114), -0.77 (95% CI: -1.21, -0.32); total body (four studies, n = 157), -0.61 (95% CI: -0.77, -0.45). The small number of observations in the subgroup analyses resulted in a high degree of uncertainty, limiting interpretation. Estimated prevalence of BMD Z-scores ≤ -2.0 was 8% (95% CI: 5%, 13%; four studies, n = 221) and < -1.0 was 42% (95% CI: 35%, 51%; five studies, n = 144). CONCLUSIONS Adults with PKU had lower BMD Z-scores than the reference (non-PKU) population but < 1 in 10 were below the expected range for age. The low number of studies prevents identification of which population characteristics are most impacting BMD. This meta-analysis was supported by BioMarin Pharmaceutical Inc., Novato, CA and is registered with the Research Registry (reviewregistry1476).
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Affiliation(s)
- Júlio C Rocha
- NOVA Medical School/Faculdade de Ciências Médicas (NMS/FCM), Universidade NOVA de Lisboa, Lisboa, Portugal.
- Reference Centre of Inherited Metabolic Diseases (RC-IMD), Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal.
- CINTESIS@RISE, Nutrition and Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisboa, Portugal.
| | - Álvaro Hermida
- University of Santiago de Compostela, Santiago de Compostela, Spain
| | | | | | | | - Sarah Rose
- BioMarin Pharmaceutical Inc, Novato, CA, USA
| | | | - Kirsten K Ahring
- Clinic for PKU, Copenhagen University Hospital, Copenhagen, Denmark
| | - André L S Pessoa
- Federal University of Ceará - UFC, Fortaleza, CE, Brazil
- Hospital Infantil Albert Sabin, Fortaleza, CE, Brazil
| | | | - Fran Rohr
- Met Ed Consultants, Boulder, CO, USA
| | - Anita Inwood
- Queensland Lifespan Metabolic Medicine Service, Queensland Children's Hospital, South Brisbane, QLD, Australia
| | - Nicola Longo
- University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - François Maillot
- Internal Medicine Department and Reference Center for Inherited Metabolic Disease, University of Tours, Tours, France
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Whitehall KB, Rose S, Clague GE, Ahring KK, Bilder DA, Harding CO, Hermida Á, Inwood A, Longo N, Maillot F, Muntau AC, Pessoa ALS, Rocha JC, Rohr F, Sivri S, Said J, Oshinbolu S, Sibbring GC. Systematic literature review of the somatic comorbidities experienced by adults with phenylketonuria. Orphanet J Rare Dis 2024; 19:293. [PMID: 39135125 PMCID: PMC11318169 DOI: 10.1186/s13023-024-03203-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 05/05/2024] [Indexed: 08/16/2024] Open
Abstract
BACKGROUND Phenylketonuria (PKU) is an inborn error of phenylalanine (Phe) metabolism that, if untreated, causes Phe accumulation in the brain leading to neurophysiologic alterations and poor outcomes. Lifelong management centers on dietary Phe restriction, yet long-term complete metabolic control is unachievable for many adults. High blood Phe levels or chronic Phe and intact protein restriction in the diet may lead to somatic comorbidities. A systematic literature review was conducted to evaluate somatic comorbidities experienced by adults with PKU. METHODS Clinical and observational studies reporting somatic comorbidities experienced by individuals with PKU aged ≥ 16 years (or classified as adults) evaluating a Phe-restricted diet with or without pharmacologic therapy versus no therapeutic intervention (including healthy controls), or pharmacologic therapy versus a Phe-restricted diet alone, were identified. PubMed® was searched (February 1, 2022 and updated November 1, 2023), using a pre-defined search strategy, followed by two-stage screening and data extraction. Included studies were grouped by PKU population comparison. RESULTS 1185 records were screened; 51 studies across 12,602 individuals were extracted. Bone-related abnormalities were the most reported outcome (n = 21); several outcome measures were used. Original study groupings included: Phe-restricted diet versus healthy controls or reference values (n = 40); treatment-adherent versus those non-adherent (n = 12). Additional groups added as part of a protocol amendment included: different Phe-restricted diets (n = 4); severe versus less severe disease (n = 5). Vote counting indicated a higher burden of ≥ 1 comorbidity (or outcome measure) for the Phe-restricted diet group by 37 of 38 studies included in the analysis of Phe-restricted diet versus healthy controls; higher burden in healthy controls was reported in 12 studies. Vote counting was similar between those treatment adherent (n = 7) versus non-adherent (n = 10). CONCLUSIONS Adults with PKU have a higher comorbidity burden than a non-PKU population. More robust studies are needed to better understand the relationship between effective metabolic control and comorbidity burden, using consistent outcome measures. This SLR was supported by BioMarin Pharmaceutical Inc., Novato, CA, and is registered with the Research Registry (reviewregistry1476).
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Affiliation(s)
| | - Sarah Rose
- BioMarin Pharmaceutical Inc., 105 Digital Drive, Novato, CA, 94949, USA
| | - Gillian E Clague
- BioMarin Pharmaceutical Inc., 105 Digital Drive, Novato, CA, 94949, USA
| | - Kirsten K Ahring
- Clinic for PKU, Copenhagen University Hospital, Copenhagen, Denmark
| | - Deborah A Bilder
- Huntsman Mental Health Institute, University of Utah, Salt Lake City, UT, USA
| | | | - Álvaro Hermida
- University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Anita Inwood
- Queensland Lifespan Metabolic Medicine Service, Queensland Children's Hospital, South Brisbane, QLD, Australia
| | - Nicola Longo
- University of Utah School of Medicine, Salt Lake City, UT, USA
| | - François Maillot
- Internal Medicine Department and Reference Center for Inherited Metabolic Disease, and the University of Tours, Tours, France
| | - Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - André L S Pessoa
- Federal University of Ceará - UFC, Fortaleza, Ceará, Brazil
- Hospital Infantil Albert Sabin, Fortaleza, Ceará, Brazil
| | - Júlio C Rocha
- NOVA Medical School/Faculdade de Ciências Médicas (NMS/FCM), Universidade NOVA de Lisboa, Lisbon, Portugal
- Reference Centre of Inherited Metabolic Diseases (RC-IMD), Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal
- Nutrition & Metabolism, CINTESIS, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Fran Rohr
- Met Ed Consultants, Boulder, CO, USA
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Scala I, Brodosi L, Rovelli V, Noto D, Burlina A. Management of patients with phenylketonuria (PKU) under enzyme replacement therapy: An Italian model (expert opinion). Mol Genet Metab Rep 2024; 39:101065. [PMID: 38425869 PMCID: PMC10899016 DOI: 10.1016/j.ymgmr.2024.101065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 03/02/2024] Open
Abstract
Objective Phenylketonuria (PKU) is a metabolic disorder necessitating lifelong management to prevent severe neurological impairments. This paper synthesises clinical practices from Italian specialist centres to delineate a unified approach for administering pegvaliase, a novel enzyme replacement therapy for PKU. Methods Virtual meetings convened in September 2022, gathering a steering committee (SC) of experts from five Italian centres specialising in PKU. The SC reviewed, and discussed clinical practices, and formulated recommendations for pegvaliase treatment. Results The SC outlined a comprehensive treatment roadmap for PKU management with pegvaliase, emphasising the importance of multidisciplinary care teams, patient selection, pre-treatment evaluation, and education. Recommendations include initial hospital-based pegvaliase administration, regular monitoring of phenylalanine and tyrosine levels, dietary adjustments, and management of adverse events. A consensus was reached on the need for a digital database to manage treatment plans and enhance communication between healthcare professionals and patients. Conclusion The expert panel's consensus highlights the complexity of PKU management and the necessity for a coordinated, patient-centred approach. The recommendations aim to standardise care across Italian centres and provide a framework for integrating pegvaliase therapy into clinical practice, potentially informing international guidelines. Further research is warranted to evaluate the long-term impact of these practices on patient outcomes and quality of life.
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Affiliation(s)
- Iris Scala
- Clinical Genetics Unit, Department of Maternal and Child Health, “Federico II” University Hospital, Naples, Italy
| | - Lucia Brodosi
- Department of Medical and Surgical Sciences, “Alma Mater” University, Sant'Orsola-Malpighi Hospital, Bologna, Italy
- Clinical Nutrition and Metabolism Unit, IRCCS AOUBO, Bologna, Italy
| | - Valentina Rovelli
- Clinical Department of Pediatrics, University of Milan, ASST Santi Paolo e Carlo, San Paolo Hospital, Milan, Italy
| | - Davide Noto
- Department of Health Promotion, Maternal and Child Health, Internal and Specialized Medicine of Excellence "G. D. Alessandro" (PROMISE), University of Palermo, Italy
| | - Alberto Burlina
- Division of Inborn Metabolic Diseases, Department of Diagnostic Services, University Hospital of Padua, Padua, Italy
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Dobrowolski SF, Tourkova IL, Larrouture QC, Blair HC. Creatine energy substrate increases bone density in the Pah enu2 classical PKU mouse in the context of phenylalanine restriction. Mol Genet Metab Rep 2023; 36:100996. [PMID: 37588420 PMCID: PMC10425935 DOI: 10.1016/j.ymgmr.2023.100996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 08/18/2023] Open
Abstract
Pathophysiology of osteopenia in phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU) is poorly characterized. The Pahenu2 mouse is universally osteopenic where dietary phenylalanine (Phe) management with amino acid defined chow does not improve bone density. We previously demonstrated Pahenu2 osteopenia owes to a skeletal stem cell (SSC) developmental deficit mediated by energy dysregulation and oxidative stress. This investigation demonstrates complexity of Pahenu2 SSC energy dysregulation. Creatine use by bone tissue is recognized. In vitro Pahenu2 SSCs in osteoblast differentiation respond to creatine with increased in situ alkaline phosphatase activity and increased intracellular ATP content. Animal studies applied a 60-day creatine regimen to Pahenu2 and control cohorts. Control cohorts include unaffected littermates (wt/wt), Pahenu2 receiving no intervention, and dietary Phe restricted Pahenu2. Experimental cohorts (Phe unrestricted Pahenu2, Phe restricted Pahenu2) were provided 1% creatine ad libitum in water. After 60 days, microcomputed tomography assessed bone metrics. Equivalent osteopenia occurs in Phe-restricted and untreated Pahenu2 control cohorts. In Phe unrestricted Pahenu2, creatine was without effect as bone density remained equivalent to Pahenu2 control cohorts. Alternatively, Phe-restricted Pahenu2 receiving creatine present increased bone density. We hypothesize small molecule dysregulation in untreated Pahenu2 disallows creatine utilization; therefore, osteopenia persisted. Dietary Phe restriction enables creatine utilization to enhance SSC osteoblast differentiation and improve in vivo bone density. PKU intervention singularly focused on Phe reduction enables residual disease including osteopenia and neurologic elements. Intervention concurrently addressing Phe homeostasis and energy dysregulation will improve disease elements refractory to standard of care Phe reduction mono-therapy.
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Affiliation(s)
- Steven F. Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America
| | - Irina L. Tourkova
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America
- Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA 15261, United States of America
| | - Quitterie C. Larrouture
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America
- Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA 15261, United States of America
| | - Harry C. Blair
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America
- Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA 15261, United States of America
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Rovelli V, Ercoli V, Dionigi AR, Paci S, Salvatici E, Zuvadelli J, Banderali G. Low bone mineralization in phenylketonuria may be due to undiagnosed metabolic acidosis. Mol Genet Metab Rep 2023; 36:100998. [PMID: 37600232 PMCID: PMC10432846 DOI: 10.1016/j.ymgmr.2023.100998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023] Open
Abstract
Background Dietary intervention is to date the mainstay treatment to prevent toxic phenylalanine (Phe) accumulation in PKU patients. Despite success preventing central nervous system damage, there is increasing evidence of possible other unfavorable outcomes affecting other systems, e.g. kidney and bone; underlying mechanisms are yet to be fully elucidated. Methods This observational, cross-sectional and descriptive study investigated 20 adult with PKU evaluating biochemical parameters, BMD measurements and extrapolating data from 3-days food records and protein substitutes (PS) and special low protein foods (SLPF) composition. Results Blood gas venous analysis (VBG) indices were indicative of metabolic acidosis in 60% of PKU patients and VBG pH significantly correlated with BMD's Z-score (p-value = 0.022) even if its overall mean was in range (-1.29). Low bone mineral density for chronological age (Z-score < - 2.0) was found in 4 patients (20%). Indices of kidney function were not impaired. All used PS had a moderate excess of acidity, while SLPF were alkalizing and type/variety of consumed vegetables did not determine significant changes in acid-base equilibrium. Total intakes of potassium and magnesium were lower than expected. Discussion PKU patients seem to be at risk of metabolic acidosis, directly linked to possible low bone mineralization. This may be related to the acidic composition of PS, potentially capable of acidifying the entire diet. Reported low intakes of potassium and magnesium may be relevant to these observations. Further studies are needed to better address these topics.
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Affiliation(s)
- Valentina Rovelli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Vittoria Ercoli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Alice Re Dionigi
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Sabrina Paci
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Elisabetta Salvatici
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Juri Zuvadelli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Giuseppe Banderali
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
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Dobrowolski SF, Phua YL, Tourkova IL, Sudano C, Vockley J, Larrouture QC, Blair HC. Glutamine energy substrate anaplerosis increases bone density in the Pah enu2 classical PKU mouse in the absence of phenylalanine restriction. JIMD Rep 2022; 63:446-452. [PMID: 36101821 PMCID: PMC9458609 DOI: 10.1002/jmd2.12308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/25/2022] [Accepted: 05/30/2022] [Indexed: 11/09/2022] Open
Abstract
Osteopenia is an under-investigated clinical presentation of phenylalanine hydroxylase (PAH)-deficient phenylketonuria (PKU). While osteopenia is not fully penetrant in human PKU, the Pahenu2 mouse is universally osteopenic and ideal to study the phenotype. We determined Pahenu2 mesenchymal stem cells (MSCs) are developmentally impaired in the osteoblast lineage. Moreover, we determined energy dysregulation and oxidative stress contribute to the osteoblast developmental deficit. The MSC preferred substrate glutamine (Gln) was applied to enhance energy homeostasis. In vitro Pahenu2 MSCs, in the context of 1200 μM Phe, respond to Gln with increased in situ alkaline phosphatase activity indicating augmented osteoblast differentiation. Oximetry applied to Pahenu2 MSCs in osteoblast differentiation show Gln energy substrate increases oxygen consumption, specifically maximum respiration and respiratory reserve. For 60 days post-weaning, Pahenu2 animals received either no intervention (standard lab chow), amino acid defined chow maintaining plasma Phe at ~200 μM, or standard lab chow where ad libitum water was a 2% Gln solution. Bone density was assessed by microcomputed tomography and bone growth assessed by dye labeling. Bone density and dye labeling in Phe-restricted Pahenu2 was indistinguishable from untreated Pahenu2. Gln energy substrate provided to Pahenu2, in the context of uncontrolled hyperphenylalaninemia, present increased bone density and dye labeling. These data provide further evidence that Pahenu2 MSCs experience a secondary energy deficit that is responsive both in vitro and in vivo to Gln energy substrate and independent of hyperphenylalaninemia. Energy support may have effect to treat human PKU osteopenia and elements of PKU neurologic disease resistant to standard of care systemic Phe reduction. Glutamine energy substrate anaplerosis increased Pahenu2 bone density and improved in vitro MSC function in the context of hyperphenylalaninemia in the classical PKU range.
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Affiliation(s)
- Steven F. Dobrowolski
- Department of PathologyUniversity of Pittsburgh, School of MedicinePittsburghPennsylvaniaUSA
| | - Yu Leng Phua
- Division of Medical Genetics and GenomicsChildren's Hospital of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Department of Genetics and Genomic SciencesIcahn School of Medicine at Mount SinaiNew YorkUSA
| | - Irina L. Tourkova
- Department of PathologyUniversity of Pittsburgh, School of MedicinePittsburghPennsylvaniaUSA
- Pittsburgh Veteran's Affairs Medical CenterPittsburghPennsylvaniaUSA
| | - Cayla Sudano
- Department of PathologyUniversity of Pittsburgh, School of MedicinePittsburghPennsylvaniaUSA
| | - Jerry Vockley
- Division of Medical Genetics and GenomicsChildren's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Quitterie C. Larrouture
- Department of PathologyUniversity of Pittsburgh, School of MedicinePittsburghPennsylvaniaUSA
- Pittsburgh Veteran's Affairs Medical CenterPittsburghPennsylvaniaUSA
| | - Harry C. Blair
- Department of PathologyUniversity of Pittsburgh, School of MedicinePittsburghPennsylvaniaUSA
- Pittsburgh Veteran's Affairs Medical CenterPittsburghPennsylvaniaUSA
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Dobrowolski SF, Phua YL, Vockley J, Goetzman E, Blair HC. Phenylketonuria oxidative stress and energy dysregulation: Emerging pathophysiological elements provide interventional opportunity. Mol Genet Metab 2022; 136:111-117. [PMID: 35379539 PMCID: PMC9832337 DOI: 10.1016/j.ymgme.2022.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 01/13/2023]
Abstract
Phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU) is rightfully considered the paradigm treatable metabolic disease. Dietary substrate restriction (i.e. phenylalanine (Phe) restriction) was applied >60 years ago and remains the primary PKU management means. The traditional model of PKU neuropathophysiology dictates blood Phe over-representation directs asymmetric blood:brain barrier amino acid transport through the LAT1 transporter with subsequent increased cerebral Phe concentration and low concentrations of tyrosine (Tyr), tryptophan (Trp), leucine (Leu), valine (Val), and isoleucine (Ile). Low Tyr and Trp concentrations generate secondary serotonergic and dopaminergic neurotransmitter paucities, widely attributed as drivers of PKU neurologic phenotypes. White matter disease, a central PKU characteristic, is ascribed to Phe-mediated tissue toxicity. Impaired cerebral protein synthesis, by reduced concentrations of non-Phe large neutral amino acids, is another cited pathological mechanism. The PKU amino acid transport model suggests Phe management should be more efficacious than is realized, as even early identified, continuously treated patients that retain therapy compliance into adulthood, demonstrate neurologic disease elements. Reduced cerebral metabolism was an early-recognized element of PKU pathology. Legacy data (late 1960's to mid-1970's) determined the Phe catabolite phenylpyruvate inhibits mitochondrial pyruvate transport. Respirometry of Pahenu2 cerebral mitochondria have attenuated respiratory chain complex 1 induction in response to pyruvate substrate, indicating reduced energy metabolism. Oxidative stress is intrinsic to PKU and Pahenu2 brain tissue presents increased reactive oxygen species. Phenylpyruvate inhibits glucose-6-phosphate dehydrogenase that generates reduced niacinamide adenine dinucleotide phosphate the obligatory cofactor of glutathione reductase. Pahenu2 brain tissue metabolomics identified increased oxidized glutathione and glutathione disulfide. Over-represented glutathione disulfide argues for reduced glutathione reductase activity secondary to reduced NADPH. Herein, we review evidence of energy and oxidative stress involvement in PKU pathology. Data suggests energy deficit and oxidative stress are features of PKU pathophysiology, providing intervention-amenable therapeutic targets to ameliorate disease elements refractory to standard of care.
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Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America.
| | - Yu Leng Phua
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Jerry Vockley
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Eric Goetzman
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Harry C Blair
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America; Veteran's Affairs Medical Center, Pittsburgh, PA, United States of America
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Bu T, Zhang L, Liu L, Yu S, Zheng J, Wu J, Yang K. Evaluation of the anti-osteoporotic effect of a low-phenylalanine whey protein hydrolysate in an ovariectomized mice model. Food Funct 2022; 13:3957-3967. [PMID: 35293905 DOI: 10.1039/d1fo04030h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A phenylalanine (Phe)-restricted diet is indispensable to control the blood Phe for individuals with phenylketonuria (PKU), who are also confronted with progressive bone impairment. Thus, the development of a low-Phe protein substitute that could positively regulate bone metabolism is desired for their bone health. Our previous study reported the preparation of a low-Phe containing whey hydrolysate (LPH) from a selected whey protein hydrolysate (TAH). However, the effect of LPH on the bone status is unknown. In this study, we used an ovariectomized (OVX) mice model to evaluate the anti-osteoporotic potential of oral administration of whey protein concentrate (WPC, protein control), TAH, and LPH on bone physiology and bone metabolism. The results showed that after 12 weeks of treatment, the decreased bone mineral density, the deteriorated trabecular microarchitecture, and the reduced ultimate load due to ovariectomy were significantly attenuated by two whey protein hydrolysates (TAH and LPH); meanwhile, the body weight, uterine weight, bone composition, and the femoral elastic load of OVX mice had not been significantly affected by whey samples. In addition, LPH and TAH dual-regulated bone remodeling in OVX mice through triggering osteogenesis (promoted the expression of runt-related protein 2 (Runx2) and osteoformation markers) and inhibiting osteoresorption as well as inflammation. The modulated mitogen-activated protein kinase signaling and the inhibited nuclear factor κB signaling by LPH and TAH might relate to the dual-regulatory activities on bone. Overall, in the OVX mice model, LPH exerted higher osteoprotective potential than TAH of the same dose by activating the bone formation markers and inhibiting the inflammatory status. The current study demonstrated for the first time the potential use of a low-Phe whey hydrolysate, a protein substitute for PKU individuals, in the prevention of osteoporosis.
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Affiliation(s)
- Tingting Bu
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310014, China.
| | - Ling Zhang
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310014, China.
| | - Ling Liu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Songfeng Yu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Jiexia Zheng
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Jianping Wu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Kai Yang
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310014, China.
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Glycomacropeptide in PKU-Does It Live Up to Its Potential? Nutrients 2022; 14:nu14040807. [PMID: 35215457 PMCID: PMC8875363 DOI: 10.3390/nu14040807] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/30/2022] [Accepted: 02/07/2022] [Indexed: 02/01/2023] Open
Abstract
The use of casein glycomacropeptide (CGMP) as a protein substitute in phenylketonuria (PKU) has grown in popularity. CGMP is derived from κ casein and is a sialic-rich glycophosphopeptide, formed by the action of chymosin during the production of cheese. It comprises 20–25% of total protein in whey products and has key biomodulatory properties. In PKU, the amino acid sequence of CGMP has been adapted by adding the amino acids histidine, leucine, methionine, tyrosine and tryptophan naturally low in CGMP. The use of CGMP compared to mono amino acids (L-AAs) as a protein substitute in the treatment of PKU promises several potential clinical benefits, although any advantage is supported only by evidence from non-PKU conditions or PKU animal models. This review examines if there is sufficient evidence to support the bioactive properties of CGMP leading to physiological benefits when compared to L-AAs in PKU, with a focus on blood phenylalanine control and stability, body composition, growth, bone density, breath odour and palatability.
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10
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Kenneson A, Singh RH. Natural history of children and adults with phenylketonuria in the NBS-PKU Connect registry. Mol Genet Metab 2021; 134:243-249. [PMID: 34654619 DOI: 10.1016/j.ymgme.2021.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 10/01/2021] [Accepted: 10/02/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE Phenylalanine hydroxylase deficiency, or phenylketonuria (PKU), is a rare autosomal recessive metabolic disorder. Early diagnosis via newborn screening (NBS) and initiation of treatment prevent the development of cognitive impairment and other co-morbidities. The purpose of this study is to describe the natural history of PKU in the United States, including prevalence of co-morbidities and predictors of outcomes. METHODS We analyzed data from a self-report survey in the NBS-PKU Connect online registry. We describe the participants' nutrition management strategies, barriers to management, outcomes of bone disorders, skin, and psychological co-morbidities, and the use of special education or other special services. Predictors of outcomes were identified and assessed, including the impact of sex, age, age at diagnosis, blood phenylalanine concentration, use of sapropterin, use of medical food, adherence to prescribed diet, use of low protein modified foods, whether they had ever been off-diet, and use of tyrosine supplementation. RESULTS The 219 respondents included individuals with PKU or hyperphenylalanemia (n = 78), or their caregivers (n = 141). Most (84.3%) started treatment before the age of two weeks. About one-third indicated that they had been off-diet at some point in their lives, and 81.4% reported that they currently adhered to their prescribed diet, with adherence to prescribed diet decreasing with age. Blood phenylalanine concentration was under the recommended threshold of 360 μmol/L for 68.5% of participants. One-quarter of respondents reported psychological co-morbidities, with anxiety and ADD/ADHD being the most common. The incidence of psychological co-morbidities increased with age and with ever having been off diet. Special education or other special services were more likely to be reported by individuals who were diagnosed after one week of age. Skin disorders such as acne and eczema were more common in females than males, and a minority of participants reported bone disorders. CONCLUSIONS Despite recommendations to maintain blood phenylalanine concentrations in the therapeutic range throughout life, it is not uncommon for adults with PKU to discontinue dietary management of their disorder. Early diagnosis was associated with reduced need for special education or other special services, and continuous treatment was associated with decreased psychological co-morbidities.
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Affiliation(s)
- Aileen Kenneson
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States of America.
| | - Rani H Singh
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States of America; Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States of America.
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11
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Dobrowolski SF, Tourkova IL, Sudano CR, Larrouture QC, Blair HC. A New View of Bone Loss in Phenylketonuria. Organogenesis 2021; 17:50-55. [PMID: 34432558 DOI: 10.1080/15476278.2021.1949865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Osteopenia is common in phenylalanine hydroxylase deficient phenylketonuria (PKU). PKU is managed by limiting dietary phenylalanine. Osteopenia in PKU might reflect a therapeutic diet, with reduced bone forming materials. However, osteopenia occurs in patients who never received dietary therapy or following short-term therapy. Humans and animal studies find no correlation between bone loss, plasma hyperphenylalaninemia, bone formation, and resorption markers. Work in the Pahenu2 mouse recently showed a mesenchymal stem cell (MSC) developmental defect in the osteoblast pathway. Specifically, Pahenu2 MSCs are affected by energy dysregulation and oxidative stress. In PKU, MSCs oximetry and respirometry show mitochondrial respiratory-chain complex 1 deficit and over-representation of superoxide, producing reactive oxygen species affecting mitochondrial function. Similar mechanisms are involved in aging bone and other rare defects including alkaptonuria and homocysteinemia. Novel interventions to support energy and reduce oxidative stress may restore bone formation PKU patients, and in metabolic diseases with related mechanisms.
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Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Irina L Tourkova
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA, USA
| | - Cayla R Sudano
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Quitterie C Larrouture
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA, USA
| | - Harry C Blair
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.,Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA, USA
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12
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Dobrowolski SF, Sudano C, Phua YL, Tourkova IL, Spridik K, Goetzman ES, Vockley J, Blair HC. Mesenchymal stem cell energy deficit and oxidative stress contribute to osteopenia in the Pah enu2 classical PKU mouse. Mol Genet Metab 2021; 132:173-179. [PMID: 33602601 PMCID: PMC9795491 DOI: 10.1016/j.ymgme.2021.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/31/2022]
Abstract
Osteopenia occurs in a subset of phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU) patients. While osteopenia is not fully penetrant in patients, the Pahenu2 classical PKU mouse is universally osteopenic, making it an ideal model of the phenotype. Pahenu2 Phe management, with a Phe-fee amino acid defined diet, does not improve bone density as histomorphometry metrics remain indistinguishable from untreated animals. Previously, we demonstrated Pahenu2 mesenchymal stem cells (MSCs) display impaired osteoblast differentiation. Oxidative stress is recognized in PKU patients and PKU animal models. Pahenu2 MSCs experience oxidative stress determined by intracellular superoxide over-representation. The deleterious impact of oxidative stress on mitochondria is recognized. Oximetry applied to Pahenu2 MSCs identified mitochondrial stress by increased basal respiration with concurrently reduced maximal respiration and respiratory reserve. Proton leak secondary to mitochondrial complex 1 dysfunction is a recognized superoxide source. Respirometry applied to Pahenu2 MSCs, in the course of osteoblast differentiation, identified a partial complex 1 deficit. Pahenu2 MSCs treated with the antioxidant resveratrol demonstrated increased mitochondrial mass by MitoTracker green labeling. In hyperphenylalaninemic conditions, resveratrol increased in situ alkaline phosphatase activity suggesting partial recovery of Pahenu2 MSCs osteoblast differentiation. Up-regulation of oxidative energy production is required for osteoblasts differentiation. Our data suggests impaired Pahenu2 MSC developmental competence involves an energy deficit. We posit energy support and oxidative stress reduction will enable Pahenu2 MSC differentiation in the osteoblast lineage to subsequently increase bone density.
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Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America.
| | - Cayla Sudano
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America
| | - Yu Leng Phua
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Irina L Tourkova
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America; Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA 15261, United States of America
| | - Kayla Spridik
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America
| | - Eric S Goetzman
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Jerry Vockley
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Harry C Blair
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America; Pittsburgh Veteran's Affairs Medical Center, Pittsburgh, PA 15261, United States of America
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13
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Bu T, Zheng J, Liu L, Li S, Wu J. Milk proteins and their derived peptides on bone health: Biological functions, mechanisms, and prospects. Compr Rev Food Sci Food Saf 2021; 20:2234-2262. [PMID: 33522110 DOI: 10.1111/1541-4337.12707] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Bone is a dynamic organ under constant metabolism (or remodeling), where a delicate balance between bone resorption and bone formation is maintained. Disruption of this coordinated bone remodeling results in bone diseases, such as osteoporosis, the most common bone disorder characterized by decreased bone mineral density and microarchitectural deterioration. Epidemiological and clinical evidence support that consumption of dairy products is beneficial for bone health; this benefit is often attributed to the presence of calcium, the physiological contributions of milk proteins on bone metabolism, however, are underestimated. Emerging evidence highlighted that not only milk proteins (including individual milk proteins) but also their derived peptides positively regulate bone remodeling and attenuate bone loss, via the regulation of cellular markers and signaling of osteoblasts and osteoclasts. This article aims to review current knowledge about the roles of milk proteins, with an emphasis on individual milk proteins, bioactive peptides derived from milk proteins, and effect of milk processing in particular fermentation, on bone metabolism, to highlight the potential uses of milk proteins in the prevention and treatment of osteoporosis, and, to discuss the knowledge gap and to recommend future research directions.
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Affiliation(s)
- Tingting Bu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, P. R. China.,ZJU-UA Joint Lab for Molecular Nutrition and Bioactive Peptides, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, P. R. China
| | - Jiexia Zheng
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, P. R. China.,ZJU-UA Joint Lab for Molecular Nutrition and Bioactive Peptides, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, P. R. China
| | - Ling Liu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, P. R. China.,ZJU-UA Joint Lab for Molecular Nutrition and Bioactive Peptides, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, P. R. China
| | - Shanshan Li
- College of Animal Sciences, Zhejiang University, Hangzhou, P. R. China
| | - Jianping Wu
- ZJU-UA Joint Lab for Molecular Nutrition and Bioactive Peptides, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, P. R. China.,Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Building, University of Alberta, Edmonton, Alberta, Canada
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14
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Aggarwal A, Northrup H, Rodriguez-Buritica DF, Hashmi SS, Saavedra H. Bone Health in Adults with Phenylketonuria: A Cross-Sectional Study. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2021. [DOI: 10.1590/2326-4594-jiems-2021-0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Anjali Aggarwal
- The University of Texas Health Science Center at Houston, USA
| | - Hope Northrup
- The University of Texas Health Science Center at Houston, USA
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15
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Leiva C, Bravo P, Arias C, Cabello J, Leal-Witt M, Salazar F, Cornejo V. 25 Hydroxy Vitamin D Level, Bone Health, Vitamin D and Calcium Intake in Chilean Patients with Phenylketonuria and Hyperphenylalaninemias. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2021. [DOI: 10.1590/2326-4594-jiems-2021-0004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- C. Leiva
- Pontificia Universidad Católica de Chile, Chile
| | - P. Bravo
- Clínica Universidad de los Andes, Chile
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16
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Stroup BM, Murali SG, Schwahn DJ, Sawin EA, Lankey EM, Bächinger HP, Ney DM. Sex effects of dietary protein source and acid load on renal and bone status in the Pah enu2 mouse model of phenylketonuria. Physiol Rep 2020; 7:e14251. [PMID: 31650703 PMCID: PMC6813258 DOI: 10.14814/phy2.14251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/07/2019] [Indexed: 01/17/2023] Open
Abstract
The low‐phenylalanine (Phe) diet with amino acid (AA) medical foods is associated with low bone mineral density (BMD) and renal dysfunction in human phenylketonuria (PKU). Our objective was to determine if diets differing in dietary protein source and acid load alter bone and renal outcomes in Pah−/− and wild‐type (WT) mice. Female and male Pah−/− (Pahenu2/enu2) and WT littermates (C57BL/6 background) were fed high‐acid AA, buffered AA (BAA), glycomacropeptide (GMP), or high‐Phe casein diets from 3 to 24 weeks of age. The BAA diet significantly reduced the excretion of renal net acid and ammonium compared with the AA diet. Interestingly, the BAA diet did not improve renal dilation in hematoxylin and eosin (H&E) stained renal sections, femoral biomechanical parameters, or femoral bone mineral content (BMC). Significantly lower femoral BMC and strength occurred in Pah−/− versus WT mice, with greater decline in female Pah−/− mice. Polyuria and mild vacuolation in the proximal convoluted tubules were observed in male Pah−/− and WT mice fed the high‐acid AA diet versus absent/minimal cortical vacuolation in males fed the GMP, BAA, or casein diets. Vacuole contents in male mice were proteinaceous. Cortical vacuolation was absent in female mice. Dilated medullary tubules were observed in all Pah−/− mice, except for male Pah−/− mice fed the GMP diet. In summary, the PKU genotype and diet showed differential effects on renal and bone status in male and female mice. Renal status improved in male Pah−/− mice fed the GMP diet.
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Affiliation(s)
- Bridget M Stroup
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Sangita G Murali
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | | | - Emily A Sawin
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Emma M Lankey
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Hans Peter Bächinger
- Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland, Oregon
| | - Denise M Ney
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
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17
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Lubout CMA, Blanco FA, Bartosiewicz K, Feillet F, Gizewska M, Hollak C, van der Lee JH, Maillot F, Stepien KM, Wagenmakers MAEM, Welsink‐Karssies MM, van Spronsen FJ, Bosch AM. Bone mineral density is within normal range in most adult phenylketonuria patients. J Inherit Metab Dis 2020; 43:251-258. [PMID: 31587319 PMCID: PMC7078943 DOI: 10.1002/jimd.12177] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 09/09/2019] [Accepted: 09/25/2019] [Indexed: 12/30/2022]
Abstract
Low bone mineral density (BMD) as a risk factor for fractures has been a long-standing concern in phenylketonuria (PKU). It is hypothesised that the disease itself or the dietary treatment might lead to a low BMD. Previous studies show conflicting results of BMD in PKU due to differences in age, techniques to assess BMD and criteria used. To assess the prevalence of low BMD and define possible risk factors in a large number of adult, early treated PKU (ETPKU) patients. European centres were invited for a survey, collecting retrospective data including results of dual-energy X-ray absorptiometry (DXA) scans of adult ETPKU patients. BMD of 183 adult ETPKU patients aged 18-46 (median age 28, all females premenopausal) years was lower than in the general population at most skeletal sites but the frequency of low BMD (Z-score <-2) was at maximum 5.5%. No risk factors for low BMD in PKU patients could be identified. Low BMD occurs only in a small subset of PKU patients. DXA scans should be considered for well controlled patients from age 35-40 years and up and on indication in those PKU patients considered to be at increased risk for fractures.
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Affiliation(s)
- Charlotte M. A. Lubout
- Department of PediatricsEmma Children's Hospital, Amsterdam UMC – Location AMCAmsterdamThe Netherlands
| | | | - Katarzyna Bartosiewicz
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental AgePomeranian Medical University in SzczecinSzczecinPoland
| | - François Feillet
- Department of Pediatrics, Hôpital d'Enfants BraboisCHU NancyNancyFrance
| | - Maria Gizewska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental AgePomeranian Medical University in SzczecinSzczecinPoland
| | - Carla Hollak
- Department of Internal Medicine, Division of Endocrinology and MetabolismAmsterdam UMC – Location AMCAmsterdamThe Netherlands
| | - Johanna H. van der Lee
- Pediatric Clinical Research Office, Woman‐Child CenterAmsterdam UMC – Location AMCAmsterdamThe Netherlands
| | - François Maillot
- Service de Médecine Interne, CHRU de Tours, Université de ToursUMR INSERMToursFrance
| | - Karolina M. Stepien
- Mark Holland Metabolic Unit, Adult Inherited Metabolic DisordersSalford Royal NHS Foundation TrustSalfordUnited Kingdom
| | - Margreet A. E. M. Wagenmakers
- Center for lysosomal and metabolic disease, Department of Internal Medicine, Erasmus MCUniversity Medical Center RotterdamRotterdamThe Netherlands
| | - Mendy M. Welsink‐Karssies
- Department of PediatricsEmma Children's Hospital, Amsterdam UMC – Location AMCAmsterdamThe Netherlands
| | - Francjan J. van Spronsen
- Section of Metabolic Diseases, Beatrix Children's HospitalUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Annet M. Bosch
- Department of PediatricsEmma Children's Hospital, Amsterdam UMC – Location AMCAmsterdamThe Netherlands
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18
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Krüger CCH, Azevedo TD, Piltz MT, Silva ÁT, Cândido LMB. Casein-derived peptides as an alternative ingredient for low-phenylalanine diets. NUTR HOSP 2019; 36:718-722. [PMID: 30958685 DOI: 10.20960/nh.2391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023] Open
Abstract
Introduction: casein-derived peptides can be liberated both in vivo via normal digestion of casein, as well as in vitro via enzymatic hydrolysis. These peptides were suggested to have biological activity. Objectives: the aim of this study was to describe the production and characterization of casein peptides and to explore the potential of these peptides as an option for low-phenylalanine diets. Methods: peptides were produced by tryptic hydrolysis of sodium caseinate and acid precipitation with HCl, followed by precipitation with ethanol or aggregation of CaCl2 or ZnSO4. Results: the amino acid analysis revealed a significant reduction in the amount of phenylalanine from the original protein. Conclusion: casein-derived peptides could be a future alternative of short chain peptides to low-phenylalanine formulations.
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Affiliation(s)
| | - Thaise D Azevedo
- Food and Nutrition Post Graduate Program. Federal University of Paraná
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19
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Dobrowolski SF, Tourkova IL, Robinson LJ, Secunda C, Spridik K, Blair HC. A bone mineralization defect in the Pah enu2 model of classical phenylketonuria involves compromised mesenchymal stem cell differentiation. Mol Genet Metab 2018; 125:193-199. [PMID: 30201326 PMCID: PMC6542264 DOI: 10.1016/j.ymgme.2018.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/20/2018] [Accepted: 08/20/2018] [Indexed: 11/29/2022]
Abstract
Osteopenia is observed in some patients affected by phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU). Bone density studies, in diverse PKU patient cohorts, have demonstrated bone disease is neither fully penetrant nor uniform in bone density loss. Biochemical assessment has generated a muddled perspective regarding mechanisms of the PKU bone phenotype where the participation of hyperphenylalaninemia remains unresolved. Osteopenia is realized in the Pahenu2 mouse model of classical PKU; although, characterization is incomplete. We characterized the Pahenu2 bone phenotype and assessed the effect of hyperphenylalaninemia on bone differentiation. Employing Pahenu2 and control animals, cytology, static and dynamic histomorphometry, and biochemistry were applied to further characterize the bone phenotype. These investigations demonstrate Pahenu2 bone density is decreased 33% relative to C57BL/6; bone volume/total volume was similarly decreased; trabecular thickness was unchanged while increased trabecular spacing was observed. Dynamic histomorphometry demonstrated a 25% decrease in mineral apposition. Biochemically, control and PKU animals have similar plasma cortisol, adrenocorticotropic hormone, and 25-hydroxyvitamin D. PKU animals show moderately increased plasma parathyroid hormone while plasma calcium and phosphate are reduced. These data are consistent with a mineralization defect. The effect of hyperphenylalaninemia on bone maturation was assessed in vitro employing bone-derived mesenchymal stem cells (MSCs) and their differentiation into bone. Using standard culture conditions, PAH deficient MSCs differentiate into bone as assessed by in situ alkaline phosphatase activity and mineral staining. However, PAH deficient MSCs cultured in 1200 μM PHE (metric defining classical PKU) show significantly reduced mineralization. These data are the first biological evidence demonstrating a negative impact of hyperphenylalaninemia upon bone maturation. In PAH deficient MSCs, expression of Col1A1 and Rankl are suppressed by hyperphenylalaninemia consistent with reduced bone formation and bone turnover. Osteopenia is intrinsic to PKU pathology in untreated Pahenu2 animals and our data suggests PHE toxicity participates by inhibiting mineralization in the course of MSC bone differentiation.
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Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.
| | - Irina L Tourkova
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Lisa J Robinson
- Department of Pathology, Ruby Memorial Hospital, West Virginia University, Morgantown, WV, United States
| | - Cassandra Secunda
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kayla Spridik
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Harry C Blair
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States; Veteran's Affairs Medical Center, Pittsburgh, PA, United States
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20
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Sex differences in body composition and bone mineral density in phenylketonuria: A cross-sectional study. Mol Genet Metab Rep 2018; 15:30-35. [PMID: 30023287 PMCID: PMC6047464 DOI: 10.1016/j.ymgmr.2018.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/17/2018] [Accepted: 01/17/2018] [Indexed: 11/23/2022] Open
Abstract
Background Low bone mineral density (BMD) and subsequent skeletal fragility have emerged as a long-term complication of phenylketonuria (PKU). Objective To determine if there are differences in BMD and body composition between male and female participants with PKU. Methods From our randomized, crossover trial [1] of participants with early-treated PKU who consumed a low-phenylalanine (Phe) diet combined with amino acid medical foods (AA-MF) or glycomacropeptide medical foods (GMP-MF), a subset of 15 participants (6 males, 9 females, aged 15-50 y, 8 classical and 7 variant PKU) completed one dual energy X-ray absorptiometry (DXA) scan and 3-day food records after each dietary treatment. Participants reported lifelong compliance with AA-MF. In a crossover design, 8 participants (4 males, 4 females, aged 16-35 y) provided a 24-h urine collection after consuming AA-MF or GMP-MF for 1-3 weeks each. Results Male participants had significantly lower mean total body BMD Z-scores (means ± SE, males = - 0.9 ± 0.4; females, 0.2 ± 0.3; p = 0.01) and tended to have lower mean L1-4 spine and total femur BMD Z-scores compared to female participants. Only 50% percent of male participants had total body BMD Z-scores above - 1.0 compared to 100% of females (p = 0.06). Total femur Z-scores were negatively correlated with intake of AA-MF (r = - 0.58; p = 0.048). Males tended to consume more grams of protein equivalents per day from AA-MF (means ± SE, males: 67 ± 6 g, females: 52 ± 4 g; p = 0.057). Males and females demonstrated similar urinary excretion of renal net acid, magnesium and sulfate; males showed a trend for higher urinary calcium excretion compared to females (means ± SE, males: 339 ± 75 mg/d, females: 228 ± 69 mg/d; p = 0.13). Females had a greater percentage of total fat mass compared to males (means ± SE, males: 24.5 ± 4.8%, females: 36.5 ± 2.5%; p = 0.047). Mean appendicular lean mass index was similar between males and females. Male participants had low-normal lean mass based on the appendicular lean mass index. Conclusions Males with PKU have lower BMD compared with females with PKU that may be related to higher intake of AA-MF and greater calcium excretion. The trial was registered at www.clinicaltrials.gov as NCT01428258.
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Key Words
- AA-MF, Amino acid medical foods
- ALM, Appendicular lean mass
- Amino acid
- Appendicular lean mass index
- BMD, Bone mineral density
- DXA, Dual-energy X-ray absorptiometry
- GMP-MF, Glycomacropeptide medical foods
- Glycomacropeptide
- MF, Medical foods
- Medical food
- Osteoporosis
- PAH, Phenylalanine hydroxylase
- PE, Protein equivalent
- PKU, Phenylketonuria
- PRAL, Potential renal acid load
- Phe, Phenylalanine
- RDN, Registered Dietitian Nutritionist
- Renal net acid
- TBS, Trabecular bone score
- Trabecular bone score
- Tyr, Tyrosine
- Urinary calcium excretion
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21
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Tanaka NYY, Turcato MF, Nicoletti CF, Nonino CB, Martins LD, Iannetta O, Guerreiro CT, Santos GG, Marchini JS. Effects of Short-Term Calcium Supplementation in Children and Adolescents with Phenylketonuria. J Clin Densitom 2018; 21:48-53. [PMID: 28302355 DOI: 10.1016/j.jocd.2017.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/03/2017] [Accepted: 02/13/2017] [Indexed: 10/20/2022]
Abstract
Reduction of bone mineral density and the risk of osteopenia have been reported to occur in phenylketonuria (PKU) patients. This study aimed to evaluate the short-term effects of calcium supplementation in phenylketonuric children and adolescents. The study included 18 patients with PKU aged 5-18 yr (61% male) under clinical and nutritional treatment. Evaluation of food intake, anthropometry, and biochemical and phalangeal quantitative ultrasound were performed before (phase 1) and after (phase 2) calcium supplementation (1000 mg/d) for 34 d. Statistical analysis was performed using t test for paired samples, Wilcoxon's test, and McNemar's test (p <0.05). There was an inadequate intake of phosphorus and vitamin D, the same occurring with serum concentrations of these nutrients. About 50% of the patients had an accumulation of adipose tissue measures, with a negative correlation between Z-score, body mass index, and phalangeal quantitative ultrasound (amplitude-dependent speed of sound [AD-SoS]). There was a significant difference in urinary phosphorus excretion with higher values before supplementation. Comparison of the two phases revealed significantly higher AD-SoS values after the supplementation (p = 0.017). The reduction in phosphorus excretion associated with increased AD-SoS between the two phases suggested increased bone formation, and showed no negative effects in relation to short-term calcium supplementation in children and in adolescents with PKU.
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Affiliation(s)
- Nancy Y Y Tanaka
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Marlene F Turcato
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Carolina F Nicoletti
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Carla B Nonino
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luciana D Martins
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Odilon Iannetta
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Carlos T Guerreiro
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Gisele G Santos
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Júlio S Marchini
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Osara Y, Coakley K, Devarajan A, Singh RH. Development of newborn screening connect (NBS connect): a self-reported patient registry and its role in improvement of care for patients with inherited metabolic disorders. Orphanet J Rare Dis 2017; 12:132. [PMID: 28724394 PMCID: PMC5517813 DOI: 10.1186/s13023-017-0684-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/11/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Newborn Screening Connect (NBS Connect) is a web-based self-reported patient registry and resource for individuals and families affected by disorders included in the newborn screening panel. NBS Connect was launched in 2012 by Emory University after years of planning and grassroots work by professionals, consumers, and industry. Individuals with phenylketonuria (PKU), maple syrup urine disease (MSUD) or tyrosinemia (TYR) have been recruited through distribution of outreach materials, presentations at parent organization meetings and direct recruitment at clinic appointments. Participants complete online profiles generating data on diagnosis, treatment, symptoms, outcomes, barriers to care, and quality of life. Resources such as education materials, information on the latest research and clinical trials, recipes, interactive health tracking systems, and professional support tools are described. In addition, to examine the ability of NBS Connect to generate data that guides hypothesis-driven research, data pertaining to age at diagnosis, bone health, and skin conditions in individuals with PKU were assessed. The objective of this paper is to describe the development of NBS Connect and highlight its data, resources and research contributions. RESULTS In September 2016, NBS Connect had 442 registered participants: 314 (71%) individuals with PKU, 68 (15%) with MSUD, 20 (5%) with TYR, and 40 (9%) with other disorders on the NBS panel. Age at diagnosis was less than 4 weeks in 285 (89%) of 319 respondents to this question and between 1 month and 14 years in 29 (9%) individuals. Of 216 respondents with PKU, 33 (15%) had a DXA scan in the past year. Of 217 respondents with PKU, 99 (46%) reported at least one skin condition. CONCLUSIONS NBS Connect was built and refined with feedback from all stakeholders, including individuals with inherited metabolic disorders. Based on patient-reported data, future studies can be initiated to test hypotheses such as the relationship between PKU and skin conditions. Patient registries like NBS Connect can inform hypothesis-driven research, contributing to knowledge generation and following the current trend in moving from traditional medicine towards evidence-based practice. NBS Connect will help clinicians understand long-term outcomes of rare disorders, contributing to better patient care and quality of life.
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Affiliation(s)
- Yetsa Osara
- Metabolic Genetics and Nutrition Program, Emory University, Atlanta, GA, USA. .,Department of Human Genetics, Metabolic Genetics and Nutrition Program, Emory University, 2165 North Decatur Road, Decatur, GA, 30033, USA.
| | - Kathryn Coakley
- Department of Individual, Family and Community Education, University of New Mexico, Albuquerque, NM, USA
| | - Aishwarya Devarajan
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Rani H Singh
- Metabolic Genetics and Nutrition Program, Emory University, Atlanta, GA, USA
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Wang K, Shen M, Li H, Li X, He C. Reduced bone mineral density in Chinese children with phenylketonuria. J Pediatr Endocrinol Metab 2017; 30:651-656. [PMID: 28489557 DOI: 10.1515/jpem-2016-0308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 04/03/2017] [Indexed: 12/27/2022]
Abstract
BACKGROUND Phenylketonuria (PKU) is an autosomal recessive metabolic disorder. Dietary control of classic PKU needs restriction of natural proteins. The diet results in unbalanced nutrition, which might affect the physical development of the patients. Our aim was to evaluate bone mineral density (BMD) in children with PKU. METHODS To investigate the BMD of children with PKU, 41 children with PKU and 64 healthy controls were recruited (all 3-4 years of age). Body weight and height, BMD, Phe blood levels, thyroid function, calcium, phosphorus, iron metabolism markers, and vitamin D3 were measured. RESULTS Body height and BMD of patients were lower than in controls. The BMD of controls was positively associated with age, body weight and height. In patients, BMD was positively associated with body weight. There was no correlation between Phe blood levels and BMD in patients. Blood levels of alkaline phosphatase were higher in patients compared to controls. Blood calcium levels were higher in 4-year-old patients, while the body weight was lower compared to controls. Thyroid function, iron metabolism markers, vitamin D3 levels and IGF-1 levels were normal. CONCLUSIONS Reduced BMD was observed in children with phenylketonuria, but the exact reasons for this remain to be elucidated.
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Amino Acid Medical Foods Provide a High Dietary Acid Load and Increase Urinary Excretion of Renal Net Acid, Calcium, and Magnesium Compared with Glycomacropeptide Medical Foods in Phenylketonuria. J Nutr Metab 2017; 2017:1909101. [PMID: 28546877 PMCID: PMC5436062 DOI: 10.1155/2017/1909101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 04/10/2017] [Indexed: 12/31/2022] Open
Abstract
Background. Skeletal fragility is a complication of phenylketonuria (PKU). A diet containing amino acids compared with glycomacropeptide reduces bone size and strength in mice. Objective. We tested the hypothesis that amino acid medical foods (AA-MF) provide a high dietary acid load, subsequently increasing urinary excretion of renal net acid, calcium, and magnesium, compared to glycomacropeptide medical foods (GMP-MF). Design. In a crossover design, 8 participants with PKU (16-35 y) provided food records and 24-hr urine samples after consuming a low-Phe diet in combination with AA-MF and GMP-MF for 1-3 wks. We calculated potential renal acid load (PRAL) of AA-MF and GMP-MF and determined bone mineral density (BMD) measurements using dual X-ray absorptiometry. Results. AA-MF provided 1.5-2.5-fold higher PRAL and resulted in 3-fold greater renal net acid excretion compared to GMP-MF (p = 0.002). Dietary protein, calcium, and magnesium intake were similar. GMP-MF significantly reduced urinary excretion of calcium by 40% (p = 0.012) and magnesium by 30% (p = 0.029). Two participants had low BMD-for-age and trabecular bone scores, indicating microarchitectural degradation. Urinary calcium with AA-MF negatively correlated with L1-L4 BMD. Conclusion. Compared to GMP-MF, AA-MF increase dietary acid load, subsequently increasing urinary calcium and magnesium excretion, and likely contributing to skeletal fragility in PKU. The trial was registered at clinicaltrials.gov as NCT01428258.
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Choukair D, Kneppo C, Feneberg R, Schönau E, Lindner M, Kölker S, Hoffmann GF, Tönshoff B. Analysis of the functional muscle-bone unit of the forearm in patients with phenylketonuria by peripheral quantitative computed tomography. J Inherit Metab Dis 2017; 40:219-226. [PMID: 27878409 DOI: 10.1007/s10545-016-0002-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/19/2016] [Accepted: 11/02/2016] [Indexed: 12/22/2022]
Abstract
Bone disease in patients with phenylketonuria (PKU) is incompletely characterized. We therefore analyzed, in a cross-sectional study radius macroscopic bone architecture and forearm muscle size by peripheral quantitative computed tomography (pQCT) and muscle strength by hand dynamometry in a large cohort (n = 56) of adolescent and adult patients with PKU aged 26.0 ± 8.9 (range, 11.8-41.5) years. Data were compared with a reference population (n = 700) from the DONALD study using identical methodology. We observed a significant reduction of cortical thickness (z-score -1.01 ± 0.79), Strength-Strain Index (SSI) (z-score -0.81 ± 1.03), and total bone mineral density (BMD) of the distal radius (z-score -1.05 ± 1.00). Mean muscle cross-sectional area (z-score -0.98 ± 1.19) and muscle grip force (z-score -0.64 ± 1.26) were also significantly reduced, indicating an impaired muscular system as part of the clinical phenotype of PKU. SSI positively correlated (r = 0.53, P < 0.001) with the corresponding muscle cross-sectional area in the reference population; however, the regression line slope in PKU patients was less steep (P < 0.001), indicating that bone strength is not adequately adapted to muscle force. In conclusion, the radial bone in PKU patients is characterized by reduced bone strength in relation to muscular force, decreased cortical thickness, and impaired total BMD at the metaphyseal site. These alterations indicate a mixed bone defect in PKU, both of which are due to primary alterations of bone metabolism and to secondary alterations in response to neuromuscular abnormalities.
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Affiliation(s)
- Daniela Choukair
- Department of Pediatrics I, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany.
| | - Carolin Kneppo
- Department of Pediatrics I, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Reinhard Feneberg
- Department of Pediatrics I, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
- ICON Clinical Research GmbH, Langen, Germany
| | | | - Martin Lindner
- Division of Neuropediatrics and Metabolic Medicine, Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
- University Children's Hospital Frankfurt, Frankfurt am Main, Germany
| | - Stefan Kölker
- Division of Neuropediatrics and Metabolic Medicine, Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Georg F Hoffmann
- Department of Pediatrics I, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
- Division of Neuropediatrics and Metabolic Medicine, Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
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Castro G, Hamilton V, Cornejo V. Chilean Nutrition Management Protocol for Patients With Phenylketonuria. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2017. [DOI: 10.1177/2326409816689788] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Gabriela Castro
- Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
| | - Valerie Hamilton
- Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
| | - Verónica Cornejo
- Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile
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Ney DM, Stroup BM, Clayton MK, Murali SG, Rice GM, Rohr F, Levy HL. Glycomacropeptide for nutritional management of phenylketonuria: a randomized, controlled, crossover trial. Am J Clin Nutr 2016; 104:334-45. [PMID: 27413125 PMCID: PMC4962165 DOI: 10.3945/ajcn.116.135293] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/10/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND To prevent cognitive impairment, phenylketonuria requires lifelong management of blood phenylalanine (Phe) concentration with a low-Phe diet. The diet restricts intake of Phe from natural proteins in combination with traditional amino acid medical foods (AA-MFs) or glycomacropeptide medical foods (GMP-MFs) that contain primarily intact protein and a small amount of Phe. OBJECTIVE We investigated the efficacy and safety of a low-Phe diet combined with GMP-MFs or AA-MFs providing the same quantity of protein equivalents in free-living subjects with phenylketonuria. DESIGN This 2-stage, randomized crossover trial included 30 early-treated phenylketonuria subjects (aged 15-49 y), 20 with classical and 10 with variant phenylketonuria. Subjects consumed, in random order for 3 wk each, their usual low-Phe diet combined with AA-MFs or GMP-MFs. The treatments were separated by a 3-wk washout with AA-MFs. Fasting plasma amino acid profiles, blood Phe concentrations, food records, and neuropsychological tests were obtained. RESULTS The frequency of medical food intake was higher with GMP-MFs than with AA-MFs. Subjects rated GMP-MFs as more acceptable than AA-MFs and noted improved gastrointestinal symptoms and less hunger with GMP-MFs. ANCOVA indicated no significant mean ± SE increase in plasma Phe (62 ± 40 μmol/L, P = 0.136), despite a significant increase in Phe intake from GMP-MFs (88 ± 6 mg Phe/d, P = 0.026). AA-MFs decreased plasma Phe (-85 ± 40 μmol/L, P = 0.044) with stable Phe intake. Blood concentrations of Phe across time were not significantly different (AA-MFs = 444 ± 34 μmol/L, GMP-MFs = 497 ± 34 μmol/L), suggesting similar Phe control. Results of the Behavior Rating Inventory of Executive Function were not significantly different. CONCLUSIONS GMP-MFs provide a safe and acceptable option for the nutritional management of phenylketonuria. The greater acceptability and fewer side effects noted with GMP-MFs than with AA-MFs may enhance dietary adherence for individuals with phenylketonuria. This trial was registered at www.clinicaltrials.gov as NCT01428258.
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Affiliation(s)
| | | | - Murray K Clayton
- Statistics, and Plant Pathology, University of Wisconsin-Madison, Madison, WI
| | | | - Gregory M Rice
- Waisman Center and Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI; and
| | - Frances Rohr
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Harvey L Levy
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA
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Coakley KE, Douglas TD, Goodman M, Ramakrishnan U, Dobrowolski SF, Singh RH. Modeling correlates of low bone mineral density in patients with phenylalanine hydroxylase deficiency. J Inherit Metab Dis 2016; 39:363-372. [PMID: 26883219 DOI: 10.1007/s10545-015-9910-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 11/17/2015] [Accepted: 12/04/2015] [Indexed: 11/26/2022]
Abstract
Phenylalanine hydroxylase (PAH) deficiency is an inherited metabolic disorder requiring life-long restriction of dietary protein and phenylalanine-free medical food. Low bone mineral density (BMD) is reported, but factors associated with BMD Z-score (standard deviations from normal) are unknown. We examined associations between clinical and dietary parameters and total BMD Z-score in PAH deficiency patients, and developed models to predict Z-score. Data collected from patients >4 years of age (n = 88; mean age = 18.8 y; 61 % female) included demographic, clinical, laboratory, and dietary intakes. Adjusted Spearman's correlation coefficients were calculated between parameters and TBMD Z-score, measured by dual energy x-ray absorptiometry (DXA). Parameters approaching significance (p-value < 0.10) were candidate predictors for four linear regression models predicting TBMD Z-score. To validate, model-predicted Z-scores were compared to DXA Z-scores. Mean TBMD Z-score was -0.326; 18 (20.4 %) had Z-score < -1. Z-scores were positively correlated with dietary vitamin D, calcium, and medical food intake and compliance with prescription, and negatively with dietary carbohydrate, sugar, caffeine intake, glycemic load, and prescribed medical food (grams protein/day; p-value < 0.05). The best model included medical food compliance, medical food intake, caffeine intake, and bone-specific alkaline phosphatase (r-square = 0.364). This model predicted Z-score category [normal or low (<-1)] with sensitivity = 66.7 %, likelihood ratio = 14.7, and AUC = 0.83 compared to DXA Z-score. No subjects had low BMD for chronological age (Z-score ≤ -2). Compliance with medical food prescription was the strongest predictor of TBMD Z-score. One model, if validated in a separate sample of patients with more cases of low BMD, showed potential to estimate TBMD Z-score using routine clinical patient parameters.
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Affiliation(s)
- Kathryn E Coakley
- Doctoral Program in Nutrition and Health Sciences, Laney Graduate School, Emory University, Atlanta, GA, USA.
- , 2165 North Decatur Road, Decatur, GA, 30033, USA.
| | - Teresa D Douglas
- Post-Doctoral Fellow, Department of Neurology, Emory University, Atlanta, GA, USA
| | - Michael Goodman
- Doctoral Program in Nutrition and Health Sciences, Laney Graduate School, Emory University, Atlanta, GA, USA
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Usha Ramakrishnan
- Doctoral Program in Nutrition and Health Sciences, Laney Graduate School, Emory University, Atlanta, GA, USA
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Rani H Singh
- Doctoral Program in Nutrition and Health Sciences, Laney Graduate School, Emory University, Atlanta, GA, USA
- Department of Human Genetics and Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA
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Mazzola PN, Teixeira BC, Schirmbeck GH, Reischak-Oliveira A, Derks TG, van Spronsen FJ, Dutra-Filho CS, Schwartz IVD. Acute exercise in treated phenylketonuria patients: Physical activity and biochemical response. Mol Genet Metab Rep 2015. [PMID: 28649544 PMCID: PMC5471389 DOI: 10.1016/j.ymgmr.2015.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Background In phenylketonuria, dietary treatment prevents most of the severe brain disease. However, patients have to follow a diet restricted in several natural components, what may cause decreased bone density and obesity. Exercise is known to improve both mental functioning and bone density also avoiding obesity, and could optimize aspects of central and peripheral outcome, regardless changes in phenylalanine (Phe) levels. However, the acute effects of exercise on metabolic parameters in phenylketonuria patients are unknown and thereby long-term adaptations are unclear. Therefore, this study aimed to evaluate patients' basal metabolic rate (BMR), and their acute response to an aerobic exercise session on plasma concentrations of Phe, tyrosine (Tyr), and branched-chain amino acids (BCAA), as well as metabolic and hormonal responses. Methods Five early- and four late diagnosed phenylketonuria patients aged 21 ± 4 years and 17 sex-, age-, and BMI-matched controls were evaluated for BMR, peak oxygen consumption (VO2peak) and plasma amino acid, glucose, lipid profile and hormonal levels. At least one week later, participants performed a 30-min aerobic exercise session (intensities individually calculated using the VO2peak results). Blood samples were collected in fasted state (moment 1, M1) and immediately after a small breakfast, which included the metabolic formula for patients but not for controls, and the exercise session (moment 2, M2). Results Phenylketonuria patients and controls showed similar BMR and physical capacities. At M1, patients presented higher Phe concentration and Phe/Tyr ratio; and lower levels of BCAA and total cholesterol than controls. Besides that, poorly controlled patients tended to stay slightly below the prescribed VO2 during exercise. Both patients and controls showed increased levels of total cholesterol and LDL at M2 compared with M1. Only controls showed increased levels of Tyr, lactate, and HDL; and decreased Phe/Tyr ratio and glucose levels at M2 compared to values at M1. Conclusions Acute aerobic exercise followed by a Phe-restricted breakfast did not change Phe concentrations in treated phenylketonuria patients, but it was associated with decreased Phe/Tyr only in controls. Further studies are necessary to confirm our results in a higher number of patients.
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Key Words
- Aerobic exercise
- BCAA, branched-chain amino acids
- BMI, body mass index
- BMR, basal metabolic rate
- Basal metabolic rate
- CTL, control
- HDL, high-density lipoprotein
- LDL, low-density lipoprotein
- N/A, not applicable
- NS, non-significant
- Natural restricted diet
- PKU
- PKU, phenylketonuria
- Phe, phenylalanine
- Phenylalanine
- Phenylketonuria
- RER, respiratory exchange ratio
- Tyr, tyrosine
- VCO2, carbon dioxide production
- VO2, oxygen consumption
- VO2peak, peak oxygen consumption
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Affiliation(s)
- Priscila Nicolao Mazzola
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos 2600 anexo, 90035-003, Porto Alegre, Brazil
- Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Bruno Costa Teixeira
- Physical Education School, UFRGS, Rua Felizardo 750, 90690-200, Porto Alegre, Brazil
| | | | | | - Terry G.J. Derks
- Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Francjan J. van Spronsen
- Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Carlos Severo Dutra-Filho
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos 2600 anexo, 90035-003, Porto Alegre, Brazil
- Departamento de Bioquímica, UFRGS, Rua Ramiro Barcelos 2600 anexo, 90035-003, Porto Alegre, Brazil
| | - Ida Vanessa Doederlein Schwartz
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90035-003, Porto Alegre, Brazil
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2350, 90035-003, Porto Alegre, Brazil
- Corresponding author at: Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90035-003, Porto Alegre, Brazil.Medical Genetics ServiceHospital de Clínicas de Porto AlegreRua Ramiro Barcelos 2350Porto Alegre90035-003Brazil
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Demirdas S, Coakley KE, Bisschop PH, Hollak CEM, Bosch AM, Singh RH. Bone health in phenylketonuria: a systematic review and meta-analysis. Orphanet J Rare Dis 2015; 10:17. [PMID: 25758373 PMCID: PMC4340652 DOI: 10.1186/s13023-015-0232-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 01/25/2015] [Indexed: 01/09/2023] Open
Abstract
Patients with Phenylketonuria (PKU) reportedly have decreased bone mineral density (BMD). The primary aim of this study was to perform a systematic review and meta-analysis to determine the extent and significance of low BMD in early treated patients with PKU. Secondary aims were to assess other bone status indicators including bone turnover markers (BTM) and to define areas for future research. Two research teams (Amsterdam, Netherlands and Atlanta, USA) performed literature searches for articles reporting data on BMD, osteopenia and osteoporosis, BTM or other bone indicators in patients with PKU. Included articles were compared between research teams and assessed for quality and risk of bias. A total of 13 unique articles were included; 11/13 articles reported BMD including a total of 360 patients. Ten out of 11 articles found BMD was significantly lower in patients with PKU. Meta-analyses for total BMD (TBMD; 3 studies; n = 133), lumbar spine BMD (LBMD; 7 studies; n = 247), and femoral neck BMD (FBMD; 2 studies; n = 78) Z-scores were performed. Overall effect sizes were: TBMD -0.45 (95% CI -0.61, -0.28); LBMD -0.70 (95% CI -0.82, -0.57); FBMD -0.96 (95% CI -1.42, -0.49). Definitions of osteopenia and osteoporosis were highly heterogeneous between studies and did not align with World Health Organization standards and the International Society for Clinical Densitometry positions on BMD measurement. Despite individual study findings of low BMD indicating higher risk of osteoporosis, pooled available data suggest reduction in BMD is not clinically important when using standard definitions of low BMD. Results from studies evaluating BTM are inconclusive. Phenylalanine concentration, vitamin D, PTH, and nutrient intake do not correlate with BMD or BTM. We recommend forthcoming studies use standard definitions of low BMD to determine clinical implications of BMD Z-scores below 0, explore cause of low BMD in the subset of patients with low BMD for chronological age (Z-score < -2) and assess fracture risk in patients with PKU.
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Affiliation(s)
- Serwet Demirdas
- Department of Paediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Katie E Coakley
- Nutrition and Health Sciences and Molecules to Mankind Programs, Laney Graduate School and Department of Human Genetics, Emory University, Atlanta, GA, USA.
| | - Peter H Bisschop
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Carla E M Hollak
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Annet M Bosch
- Department of Paediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Rani H Singh
- Metabolic Nutrition and Genetics Program Department of Human Genetics, Emory University Atlanta GA United States, Atlanta, GA, USA.
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Hansen KE, Ney D. A systematic review of bone mineral density and fractures in phenylketonuria. J Inherit Metab Dis 2014; 37:875-80. [PMID: 25005329 PMCID: PMC4208974 DOI: 10.1007/s10545-014-9735-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/05/2014] [Accepted: 06/12/2014] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Our objective was to systematically review and analyze published data on bone mineral density (BMD) and fracture rates in patients with phenylketonuria (PKU), and relationships between BMD and phenylalanine levels. METHODOLOGY We searched PubMed, CINAHL, and Cochrane databases from January 1966 to November 2013 for studies of spine BMD or fracture in PKU and control subjects. We excluded studies assessing skeletal health by ultrasound or peripheral quantitative computer tomography. Both authors reviewed abstracts for inclusion, and read full text papers to extract data. RESULTS Sixteen studies met eligibility criteria. Meta-analysis of three studies found that spine BMD was 0.100 g/cm(2) lower (95% CI, -0.110, -0.090 g/cm(2)) in 67 subjects with PKU, compared to 161 controls. Among six studies, 20% (53 of 263) of PKU subjects experienced clinical fractures. In the single study with controls, the fracture rate was 2.6 fold higher (95% CI, 1.1-6.1) after age 8 in PKU subjects, compared to healthy sibling controls. When considering a total of 12 studies in 412 subjects, nine or 75% of studies representing 71% of studied subjects reported no association between phenylalanine levels and BMD. Spine BMD is lower in PKU than control subjects, but only one study controlled for smaller body size. Existing studies suggest a clinical fracture rate of 20% among PKU subjects, but fracture rates in controls are lacking. Finally, existing data shows no consistent relationship between phenylalanine levels and BMD. Future studies are needed to clarify the etiology and health consequences of low BMD in PKU.
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Affiliation(s)
- Karen E Hansen
- Department of Medicine, Division of Rheumatology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA,
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Humphrey M, Truby H, Boneh A. New ways of defining protein and energy relationships in inborn errors of metabolism. Mol Genet Metab 2014; 112:247-58. [PMID: 24916709 DOI: 10.1016/j.ymgme.2014.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 05/14/2014] [Indexed: 12/30/2022]
Abstract
Dietary restrictions required to manage individuals with inborn errors of metabolism (IEM) are essential for metabolic control, however may result in an increased risk to both short and long-term nutritional status. Dietary factors most likely to influence nutritional status include energy intake, protein quality and quantity, micronutrient intake and the frequency and extent to which the diet must be altered during periods of increased physical or metabolic stress. Patients on the most restrictive diets, including those with intakes consisting of low levels of natural protein or those with recurrent illness or frequent metabolic decompensation carry the most nutritional risk. Due to the difficulties in determining condition specific requirements, dietary intake recommendations and nutritional monitoring tools used in patients with IEM are the same as, or extrapolated from, those used in healthy populations. As a consequence, evidence is lacking for the safest dietary prescriptions required to manage these patients long term, as tolerance to dietary therapy is generally described in terms of metabolic stability rather than long term nutritional and health outcomes. As the most frequent therapeutic dietary manipulation in IEM is alteration in dietary protein, and as protein status is critically dependent on adequate energy provision, the use of a Protein to Energy ratio (P:E ratio) as an additional tool will better define the relationship between these critical components. This could accurately define dietary quality and ensure that not only an adequate, but also a safe and balanced intake is provided.
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Affiliation(s)
- Maureen Humphrey
- Metabolic Genetics, Victorian Clinical Genetic Services, Murdoch Children's Research Institute, The Royal Children's Hospital, Flemington Road, Parkville, Victoria, Melbourne 3052, Australia; Department of Nutrition and Food Services, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Melbourne 3052, Australia; Be Active Sleep Eat (BASE) Facility, Department of Nutrition and Dietetics, Monash University, Faculty of Medicine, Nursing and Health Sciences, Level 1, 264 Ferntree Gully Road, VIC 3168, Melbourne, Australia.
| | - Helen Truby
- Be Active Sleep Eat (BASE) Facility, Department of Nutrition and Dietetics, Monash University, Faculty of Medicine, Nursing and Health Sciences, Level 1, 264 Ferntree Gully Road, VIC 3168, Melbourne, Australia.
| | - Avihu Boneh
- Metabolic Genetics, Victorian Clinical Genetic Services, Murdoch Children's Research Institute, The Royal Children's Hospital, Flemington Road, Parkville, Victoria, Melbourne 3052, Australia; Be Active Sleep Eat (BASE) Facility, Department of Nutrition and Dietetics, Monash University, Faculty of Medicine, Nursing and Health Sciences, Level 1, 264 Ferntree Gully Road, VIC 3168, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Melbourne 3052, Australia.
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Camp KM, Parisi MA, Acosta PB, Berry GT, Bilder DA, Blau N, Bodamer OA, Brosco JP, Brown CS, Burlina AB, Burton BK, Chang CS, Coates PM, Cunningham AC, Dobrowolski SF, Ferguson JH, Franklin TD, Frazier DM, Grange DK, Greene CL, Groft SC, Harding CO, Howell RR, Huntington KL, Hyatt-Knorr HD, Jevaji IP, Levy HL, Lichter-Konecki U, Lindegren ML, Lloyd-Puryear MA, Matalon K, MacDonald A, McPheeters ML, Mitchell JJ, Mofidi S, Moseley KD, Mueller CM, Mulberg AE, Nerurkar LS, Ogata BN, Pariser AR, Prasad S, Pridjian G, Rasmussen SA, Reddy UM, Rohr FJ, Singh RH, Sirrs SM, Stremer SE, Tagle DA, Thompson SM, Urv TK, Utz JR, van Spronsen F, Vockley J, Waisbren SE, Weglicki LS, White DA, Whitley CB, Wilfond BS, Yannicelli S, Young JM. Phenylketonuria Scientific Review Conference: state of the science and future research needs. Mol Genet Metab 2014; 112:87-122. [PMID: 24667081 DOI: 10.1016/j.ymgme.2014.02.013] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 01/17/2023]
Abstract
New developments in the treatment and management of phenylketonuria (PKU) as well as advances in molecular testing have emerged since the National Institutes of Health 2000 PKU Consensus Statement was released. An NIH State-of-the-Science Conference was convened in 2012 to address new findings, particularly the use of the medication sapropterin to treat some individuals with PKU, and to develop a research agenda. Prior to the 2012 conference, five working groups of experts and public members met over a 1-year period. The working groups addressed the following: long-term outcomes and management across the lifespan; PKU and pregnancy; diet control and management; pharmacologic interventions; and molecular testing, new technologies, and epidemiologic considerations. In a parallel and independent activity, an Evidence-based Practice Center supported by the Agency for Healthcare Research and Quality conducted a systematic review of adjuvant treatments for PKU; its conclusions were presented at the conference. The conference included the findings of the working groups, panel discussions from industry and international perspectives, and presentations on topics such as emerging treatments for PKU, transitioning to adult care, and the U.S. Food and Drug Administration regulatory perspective. Over 85 experts participated in the conference through information gathering and/or as presenters during the conference, and they reached several important conclusions. The most serious neurological impairments in PKU are preventable with current dietary treatment approaches. However, a variety of more subtle physical, cognitive, and behavioral consequences of even well-controlled PKU are now recognized. The best outcomes in maternal PKU occur when blood phenylalanine (Phe) concentrations are maintained between 120 and 360 μmol/L before and during pregnancy. The dietary management treatment goal for individuals with PKU is a blood Phe concentration between 120 and 360 μmol/L. The use of genotype information in the newborn period may yield valuable insights about the severity of the condition for infants diagnosed before maximal Phe levels are achieved. While emerging and established genotype-phenotype correlations may transform our understanding of PKU, establishing correlations with intellectual outcomes is more challenging. Regarding the use of sapropterin in PKU, there are significant gaps in predicting response to treatment; at least half of those with PKU will have either minimal or no response. A coordinated approach to PKU treatment improves long-term outcomes for those with PKU and facilitates the conduct of research to improve diagnosis and treatment. New drugs that are safe, efficacious, and impact a larger proportion of individuals with PKU are needed. However, it is imperative that treatment guidelines and the decision processes for determining access to treatments be tied to a solid evidence base with rigorous standards for robust and consistent data collection. The process that preceded the PKU State-of-the-Science Conference, the conference itself, and the identification of a research agenda have facilitated the development of clinical practice guidelines by professional organizations and serve as a model for other inborn errors of metabolism.
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Affiliation(s)
- Kathryn M Camp
- Office of Dietary Supplements, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Melissa A Parisi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | | | - Gerard T Berry
- Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Deborah A Bilder
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84108, USA.
| | - Nenad Blau
- University Children's Hospital, Heidelberg, Germany; University Children's Hospital, Zürich, Switzerland.
| | - Olaf A Bodamer
- University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Jeffrey P Brosco
- University of Miami Mailman Center for Child Development, Miami, FL 33101, USA.
| | | | | | - Barbara K Burton
- Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA.
| | - Christine S Chang
- Agency for Healthcare Research and Quality, Rockville, MD 20850, USA.
| | - Paul M Coates
- Office of Dietary Supplements, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Amy C Cunningham
- Tulane University Medical School, Hayward Genetics Center, New Orleans, LA 70112, USA.
| | | | - John H Ferguson
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | | | | | - Dorothy K Grange
- Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA.
| | - Carol L Greene
- University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Stephen C Groft
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Cary O Harding
- Oregon Health & Science University, Portland, OR 97239, USA.
| | - R Rodney Howell
- University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | | | - Henrietta D Hyatt-Knorr
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Indira P Jevaji
- Office of Research on Women's Health, National Institutes of Health, Bethesda, MD 20817, USA.
| | - Harvey L Levy
- Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Uta Lichter-Konecki
- George Washington University, Children's National Medical Center, Washington, DC 20010, USA.
| | | | | | | | | | - Melissa L McPheeters
- Vanderbilt Evidence-based Practice Center, Institute for Medicine and Public Health, Nashville, TN 37203, USA.
| | - John J Mitchell
- McGill University Health Center, Montreal, Quebec H3H 1P3, Canada.
| | - Shideh Mofidi
- Maria Fareri Children's Hospital of Westchester Medical Center, Valhalla, NY 10595, USA.
| | - Kathryn D Moseley
- University of Southern California Keck School of Medicine, Los Angeles, CA 90033, USA.
| | - Christine M Mueller
- Office of Orphan Products Development, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
| | - Andrew E Mulberg
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
| | - Lata S Nerurkar
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Beth N Ogata
- University of Washington, Seattle, WA 98195, USA.
| | - Anne R Pariser
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
| | - Suyash Prasad
- BioMarin Pharmaceutical Inc., San Rafael, CA 94901, USA.
| | - Gabriella Pridjian
- Tulane University Medical School, Hayward Genetics Center, New Orleans, LA 70112, USA.
| | | | - Uma M Reddy
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | | | | | - Sandra M Sirrs
- Vancouver General Hospital, University of British Columbia, Vancouver V5Z 1M9, Canada.
| | | | - Danilo A Tagle
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Susan M Thompson
- The Children's Hospital at Westmead, Sydney, NSW 2145, Australia.
| | - Tiina K Urv
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jeanine R Utz
- University of Minnesota, Minneapolis, MN 55455, USA.
| | - Francjan van Spronsen
- University of Groningen, University Medical Center of Groningen, Beatrix Children's Hospital, Netherlands.
| | - Jerry Vockley
- University of Pittsburgh, Pittsburgh, PA 15224, USA.
| | - Susan E Waisbren
- Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Linda S Weglicki
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Desirée A White
- Department of Psychology, Washington University, St. Louis, MO 63130, USA.
| | | | - Benjamin S Wilfond
- Seattle Children's Research Institute, University of Washington School of Medicine, Seattle, WA 98101, USA.
| | | | - Justin M Young
- The Young Face, Facial Plastic and Reconstructive Surgery, Cumming, GA 30041, USA.
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Kalkwarf HJ, Abrams SA, DiMeglio LA, Koo WWK, Specker BL, Weiler H. Bone densitometry in infants and young children: the 2013 ISCD Pediatric Official Positions. J Clin Densitom 2014; 17:243-57. [PMID: 24674638 DOI: 10.1016/j.jocd.2014.01.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 01/08/2014] [Indexed: 11/19/2022]
Abstract
Infants and children <5 yr were not included in the 2007 International Society for Clinical Densitometry Official Positions regarding Skeletal Health Assessment of Children and Adolescents. To advance clinical care of very young children, the International Society for Clinical Densitometry 2013 Position Development Conference reviewed the literature addressing appropriate methods and skeletal sites for clinical dual-energy X-ray absorptiometry (DXA) measurements in infants and young children and how results should be reported. DXA whole-body bone mineral content and bone mineral density for children ≥3 yr and DXA lumbar spine measurements for infants and young children 0-5 yr were identified as feasible and reproducible. There was insufficient information regarding methodology, reproducibility, and reference data to recommended forearm and femur measurements at this time. Appropriate methods to account for growth delay when interpreting DXA results for children <5 yr are currently unknown. Reference data for children 0-5 yr at multiple skeletal sites are insufficient and are needed to enable interpretation of DXA measurements. Given the current scarcity of evidence in many areas, it is likely that these positions will change over time as new data become available.
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Affiliation(s)
- Heidi J Kalkwarf
- Division of General and Community Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| | - Steven A Abrams
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Linda A DiMeglio
- Department of Pediatrics, Section of Pediatric Endocrinology and Diabetology, Indiana University, Indianapolis, IN, USA
| | - Winston W K Koo
- Department of Pediatrics, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Bonny L Specker
- Ethel Austin Martin Program in Human Nutrition, South Dakota State University, Brookings, SD, USA
| | - Hope Weiler
- School of Dietetics and Human Nutrition, McGill University, Montreal, QC, Canada
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Mirás A, Freire Corbacho A, Rodríguez García J, Leis R, Aldámiz-Echevarría L, Fraga JM, Couce ML. [Utility of bone turnover markers in metabolic bone disease detection in patients with phenylketonuria]. Med Clin (Barc) 2014; 144:193-7. [PMID: 24559543 DOI: 10.1016/j.medcli.2013.10.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 10/01/2013] [Accepted: 10/03/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND OBJECTIVE Mineral bone disease is more common in phenylketonuric patients. The objectives of this study were to determine the usefulness of biochemical bone markers to identify phenylketonuric patients with mineral bone disease (MBD) and know the underlying bone remodeling alterations. PATIENTS AND METHOD Cross-sectional study of 43 phenylketonuric patients>7 years (range: 7.1-41 years). A nutritional survey was performed and bone alkaline phosphatase (BAP), procollagen type 1 N-terminal propeptide (PNP-1), beta-crosslaps and ratio calcium/creatinine in urine were determined. RESULTS A percentage of 20.9 of patients had pathological biochemical bone markers, 90% of them being adults. BAP was decreased in 70% of them and beta-crosslaps in 42.8%. BAP values were more often pathological in phenylketonuric patients with a late diagnosis (41.7 vs. 10.7%; P<.05) and in patients with MBD (60 vs. 14.3%; P<.05). PNP-1 values and calcium/creatinine were similar among all phenylketonuric patients regardless of presenting MBD, late diagnosis or tetrahydrobipterin treatment (enzyme cofactor). Patients with decreased BAP and beta-crosslaps had lower natural protein intake: BAP (0.21 ± 0.13 vs. 0.65 ± 0.65 g/kg; P<.05); beta-crosslaps (0.29 ± 0.23 vs. 0.65 ± 0.66 g/kg; P<.05). None of the tetrahydrobiopterin treated patients showed altered values of BAP, PNP-1 or calcium/creatinine. CONCLUSIONS Adult phenylketonuric patients with lower natural protein intake tend to have lower values of BAP, which is a marker that may be useful to identify patients at risk for MBD.
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Affiliation(s)
- Alicia Mirás
- Unidad de Diagnóstico y Tratamiento de Enfermedades Metabólicas Congénitas, Servicio de Pediatría, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, España
| | - Antonio Freire Corbacho
- Servicio de Laboratorio Central, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, España
| | - Javier Rodríguez García
- Servicio de Laboratorio Central, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, España
| | - Rosaura Leis
- Unidad de Gastroenterología y Nutrición, Servicio de Pediatría, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, España
| | - Luís Aldámiz-Echevarría
- Unidad de Metabolismo, Departamento de Pediatría, Hospital de Cruces, Barakaldo, Vizcaya, España
| | - José M Fraga
- Unidad de Diagnóstico y Tratamiento de Enfermedades Metabólicas Congénitas, Servicio de Pediatría, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, España
| | - María L Couce
- Unidad de Diagnóstico y Tratamiento de Enfermedades Metabólicas Congénitas, Servicio de Pediatría, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, España.
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Abstract
PURPOSE OF REVIEW The purpose is to discuss advances in the nutritional and pharmacological management of phenylketonuria (PKU). RECENT FINDINGS Glycomacropeptide (GMP), a whey protein produced during cheese production, is a low-phenylalanine (phe) intact protein that represents a new dietary alternative to synthetic amino acids for people with PKU. Skeletal fragility is a long-term complication of PKU that based on murine research, appears to result from both genetic and nutritional factors. Skeletal fragility in murine PKU is attenuated with the GMP diet, compared with an amino acid diet, allowing greater radial bone growth. Pharmacologic therapy with tetrahydrobiopterin, acting as a molecular chaperone for phenylalanine hydroxylase, increases tolerance to dietary phe in some individuals. Large neutral amino acids inhibit phe transport across the intestinal mucosa and blood-brain barrier, and are most effective for individuals unable to comply with the low-phe diet. SUMMARY Although a low-phe synthetic amino acid diet remains the mainstay of PKU management, new nutritional and pharmacological treatment options offer alternative approaches to maintain lifelong low phe concentrations. GMP medical foods provide an alternative to amino acid formula that may improve bone health, and tetrahydrobiopterin permits some individuals with PKU to increase tolerance to dietary phe. Further research is needed to characterize the long-term efficacy of these new approaches for PKU management.
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Affiliation(s)
- Denise M. Ney
- Department of Nutritional Sciences and Waisman Center, University of Wisconsin-Madison, Milwaukee
| | - Robert D. Blank
- Department of Medicine, Division of Endocrinology, Diabetes, and Clinical Nutrition, Medical College of Wisconsin, Milwaukee
| | - Karen E. Hansen
- Department of Medicine, Division of Rheumatology, School of Medicine and Public Health, University of Wisconsin, USA
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Mirás A, Bóveda MD, Leis MR, Mera A, Aldámiz-Echevarría L, Fernández-Lorenzo JR, Fraga JM, Couce ML. Risk factors for developing mineral bone disease in phenylketonuric patients. Mol Genet Metab 2013; 108:149-54. [PMID: 23352389 DOI: 10.1016/j.ymgme.2012.12.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 12/30/2012] [Accepted: 12/30/2012] [Indexed: 10/27/2022]
Abstract
There is a compromised bone mass in phenylketonuria patients compared with normal population, but the mechanisms responsible are still a matter of investigation. In addition, tetrahydrobiopterin therapy is a new option for a significant proportion of these patients and the prevalence of mineral bone disease (MBD) in these patients is unknown. We conducted a cross-sectional observational study including 43 phenylketonuric patients. Bone densitometry, nutritional assessment, physical activity questionnaire, biochemical parameters, and molecular study were performed in all patients. Patients were stratified by phenotype, age and type of treatment. The MBD prevalence in phenylketonuria was 14%. Osteopenic and osteoporotic (n=6 patients) had an average daily natural protein intake significantly lower than the remaining (n=37) patients with PKU (14.33 ± 8.95 g vs 21.25 ± 20.85 g). Besides, a lower body mass index was found. There were no statistical differences in physical activity level, calcium, phosphorus and fat intake, and in phenylalanine, vitamin D, paratohormone, docosahexaenoic and eicosapentaenoic acid blood levels. Mutational spectrum was found in up to 30 different PAH genotypes and no relationship was established among genotype and development of MBD. None of the twelve phenylketonuric patients treated with tetrahydrobiopterin (27.9%), for an average of 7.1 years, developed MBD. Natural protein intake and blood levels of eicosapentaenoic acid were significantly higher while calcium intake was lower in these patients. This study shows that the decrease in natural protein intake can play an important role in MBD development in phenylketonuric patients. Therapy with tetrahydrobiopterin allows a more relaxed protein diet, which is associated with better bone mass.
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Affiliation(s)
- Alicia Mirás
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Travesía da Choupana s/n, 15706 Santiago de Compostela, A Coruña, Spain.
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Robert M, Rocha JC, van Rijn M, Ahring K, Bélanger-Quintana A, MacDonald A, Dokoupil K, Gokmen Ozel H, Lammardo AM, Goyens P, Feillet F. Micronutrient status in phenylketonuria. Mol Genet Metab 2013; 110 Suppl:S6-17. [PMID: 24113686 DOI: 10.1016/j.ymgme.2013.09.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Revised: 09/15/2013] [Accepted: 09/15/2013] [Indexed: 12/12/2022]
Abstract
Patients with phenylketonuria (PKU) encompass an 'at risk' group for micronutrient imbalances. Optimal nutrient status is challenging particularly when a substantial proportion of nutrient intake is from non-natural sources. In PKU patients following dietary treatment, supplementation with micronutrients is a necessity and vitamins and minerals should either be added to supplement phenylalanine-free l-amino acids or given separately. In this literature review of papers published since 1990, the prevalence of vitamin and mineral deficiency is described, with reference to age of treatment commencement, type of treatment, dietary compliance, and dietary practices. Biological micronutrient inadequacies have been mainly reported for zinc, selenium, iron, vitamin B12 and folate. The aetiology of these results and possible clinical and biological implications are discussed. In PKU there is not a simple relationship between the dietary intake and nutritional status, and there are many independent and interrelated complex factors that should be considered other than quantitative nutritional intake.
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Affiliation(s)
- M Robert
- Nutrition and Metabolism Unit, Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium
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Low bone strength is a manifestation of phenylketonuria in mice and is attenuated by a glycomacropeptide diet. PLoS One 2012; 7:e45165. [PMID: 23028819 PMCID: PMC3445501 DOI: 10.1371/journal.pone.0045165] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 08/14/2012] [Indexed: 12/03/2022] Open
Abstract
Purpose Phenylketonuria (PKU), caused by phenylalanine (phe) hydroxylase loss of function mutations, requires a low-phe diet plus amino acid (AA) formula to prevent cognitive impairment. Glycomacropeptide (GMP), a low-phe whey protein, provides a palatable alternative to AA formula. Skeletal fragility is a poorly understood chronic complication of PKU. We sought to characterize the impact of the PKU genotype and dietary protein source on bone biomechanics. Procedures Wild type (WT; Pah+/+) and PKU (Pahenu2/enu2) mice on a C57BL/6J background were fed high-phe casein, low-phe AA, and low-phe GMP diets between 3 to 23 weeks of age. Following euthanasia, femur biomechanics were assessed by 3-point bending and femoral diaphyseal structure was determined. Femoral ex vivo bone mineral density (BMD) was assessed by dual-enengy x-ray absorptiometry. Whole bone parameters were used in prinicipal component analysis. Data were analyzed by 3-way ANCOVA with genotype, sex, and diet as the main factors. Findings Regardless of diet and sex, PKU femora were more brittle, as manifested by lower post-yield displacement, weaker, as manifested by lower energy and yield and maximal loads, and showed reduced BMD compared with WT femora. Four principal components accounted for 87% of the variance and all differed significantly by genotype. Regardless of genotype and sex, the AA diet reduced femoral cross-sectional area and consequent maximal load compared with the GMP diet. Conclusions Skeletal fragility, as reflected in brittle and weak femora, is an inherent feature of PKU. This PKU bone phenotype is attenuated by a GMP diet compared with an AA diet.
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