Dietary protein and protein substitute requirements in adults with phenylketonuria: A review of the clinical guidelines

Firman, Sarah; Witard, Oliver C.; O’Keeffe, Majella; Ramachandran, Radha

doi:10.1016/j.clnu.2020.11.003

Cited by 15 publications

(17 citation statements)

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“…Minimum protein requirements are commonly derived from “safe levels” of protein intake [ 23 ] that are age-specific until the age of 19 years and then remain constant over the adult lifespan. In a recent review paper, Firman et al [ 24 ] suggests that this may not be suitable for older adults with PKU with higher demands for protein associated with ageing. More research is needed to understand optimal protein needs for adults at different life stages and to investigate the body composition of older adults with PKU.…”

Section: Discussionmentioning

confidence: 99%

Dietetic Management of Adults with Phenylketonuria (PKU) in the UK: A Care Consensus Document

et al. 2022

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There is an increasing number of adults and elderly patients with phenylketonuria (PKU) who are either early, late treated, or untreated. The principal treatment is a phenylalanine-restricted diet. There is no established UK training for dietitians who work with adults within the specialty of Inherited Metabolic Disorders (IMDs), including PKU. To address this, a group of experienced dietitians specializing in IMDs created a standard operating procedure (SOP) on the dietetic management of adults with PKU to promote equity of care in IMD dietetic services and to support service provision across the UK. The group met virtually over a period of 12 months until they reached 100% consensus on the SOP content. Areas of limited evidence included optimal blood phenylalanine reporting times to patients, protein requirements in older adults, management of weight and obesity, and management of disordered eating and eating disorders. The SOP does not include guidance on maternal PKU management. The SOP can be used as a tool for training dietitians new to the specialty and to raise the standard of education and care for patients with PKU in the UK.

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Section: Discussionmentioning

confidence: 99%

Dietetic Management of Adults with Phenylketonuria (PKU) in the UK: A Care Consensus Document

et al. 2022

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“…A further descriptive numerical summary will outline the measurements of protein status used and the findings from the studies (including any descriptive statistics and effect size where available). Due to existing concerns regarding whether current guidelines on protein requirements are adequate to offset age-related changes in protein metabolism across the adult lifespan, 4 in addition to reporting the results on protein status across the lifespan, a summary of evidence from research specific to adults and older adults will be included.…”

Section: Methods and Analysismentioning

confidence: 99%

“… 1–3 Currently, dietary management provides the mainstay of treatment and consists of altering the sources of ingested protein to limit phenylalanine intake, and supplementation with phenylalanine-free or low-phenylalanine protein sources to meet protein requirements. 4 In practice, this dietary regimen involves restricting protein intake from food and instead providing the majority (up to 80%) of protein intake from phenylalanine-free or low-phenylalanine protein substitutes, consisting of either L-amino acids (L-AA) or casein glycomacropeptide (CGMP), 5 6 and more recently, protein substitutes using prolonged-release amino acid technology. 7–9 …”

Section: Introductionmentioning

confidence: 99%

“…A key limitation of existing guidelines on dietary protein requirements for people with PKU 1–3 is that the data has been extrapolated from studies that estimated protein requirements in healthy populations. 4 These studies used nitrogen balance methodology to evaluate the minimum protein (ie, nitrogen) intake required to balance nitrogen losses at the whole-body level of physiology. 10 In contrast to the definition of a protein requirement, a protein recommendation serves to optimise metabolic function and improve health and functional outcomes in a given population group.…”

Section: Introductionmentioning

confidence: 99%

“… 1–3 However, the evidence underpinning protein requirement guidelines for dietary management of adults with PKU is limited, and in their current form may not adequately offset age-related changes in protein metabolism across the adult lifespan in people with PKU. 4 …”

Section: Introductionmentioning

confidence: 99%

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Protein status of people with phenylketonuria: a scoping review protocol

et al. 2021

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IntroductionPhenylketonuria (PKU) is a disorder of protein metabolism resulting in an accumulation of phenylalanine in the body. Dietary management consists of altering the sources of ingested protein to limit phenylalanine intake. Current dietary protein guidelines for PKU are based on limited scientific evidence, thus it remains unclear whether current practice leads to optimal protein status in people with PKU. To date, no attempt has been made to systematically evaluate the protein status of people with PKU, using a combination of validated anthropometric, biochemical and functional measurement tools. Furthermore, factors known to influence protein status in the general population warrant consideration when determining protein status in individuals with PKU, alongside factors unique to PKU such as the type of protein substitute consumed. Understanding the impact of these variables on protein status is crucial to developing a personalised approach to protein recommendations for optimising health and functional outcomes in people with PKU. Therefore, the aim of this scoping review is to examine existing evidence regarding the protein status of people with PKU, and to investigate the nutritional and lifestyle variables that influence protein status.Methods and analysisThis review will be guided by Arksey and O’Malley’s framework, along with guidance from Levac et al, Pawliuk et al and the Joanna Briggs Institute. The following databases will be searched: MEDLINE (Ovid), Embase, CENTRAL, Web of Science and Scopus, alongside grey literature. Identified literature will be assessed by two independent reviewers for inclusion. Descriptive numerical analysis will be performed and a narrative summary will accompany the tabulated results describing how study findings relate to the review questions.Ethics and disseminationThis review protocol does not require ethical approval. Findings will be disseminated through peer-reviewed publication, presented at relevant conferences, and shared with a patient research advisory group to inform discussions on future research.

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Insurance Reimbursement for Special Foods and Phenylalanine Levels in Patients With PKU in China

Wang,

Xia,

Cheng

et al. 2024

JAMA Netw Open

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ImportanceRecent changes in China’s social medical insurance reimbursement policy have impacted the financial burden of patients with phenylketonuria (PKU) for special foods. However, whether this policy change is associated with their blood phenylalanine (PHE) concentration is unclear.ObjectiveTo investigate the association between the reimbursement policy and blood PHE concentration in patients with PKU.Design, Setting, and ParticipantsThis cohort study measured the blood PHE concentrations of 167 patients with PKU across 4 newborn screening centers in China from January 2018 to December 2021. The reimbursement policy for special foods for patients with PKU at 2 centers was canceled in 2019 and restored from 2020 onwards. In contrast, the other 2 centers consistently implemented the policy. Data were analyzed from September 10 to December 6, 2023.ExposuresThe implementation and cancelation of the reimbursement policy for special foods of patients with PKU.Main Outcomes and MeasuresThe blood PHE concentration was regularly measured from 2018 to 2021. A 1-sided Z test was used to compare the mean of the blood PHE concentration between different years.ResultsAmong 167 patients with PKU (mean [SD] age, 84.4 [48.3] months; 87 males [52.1%]), a total of 4285 measurements of their blood PHE concentration were collected from 2018 to 2021. For patients at the center that canceled the reimbursement policy in 2019, the mean (SD) of the blood PHE concentrations in 2019 was 5.95 (5.73) mg/dL, significantly higher than 4.84 (4.11) mg/dL in 2018 (P &lt; .001), 5.06 (5.21) mg/dL in 2020 (P = .006), and 4.77 (4.04) mg/dL in 2021 (P &lt; .001). Similarly, for patients at the other center that canceled the policy in 2019, the mean (SD) of the blood PHE concentrations in 2019 was 5.95 (3.43) mg/dL, significantly higher than 5.34 (3.45) mg/dL in 2018 (P = .03), 5.13 (3.15) mg/dL in 2020 (P = .003), and 5.39 (3.46) mg/dL in 2021 (P = .03). On the contrary, no significant difference was observed between any of the years for patients at the 2 centers that consistently implemented the policy.Conclusions and RelevanceIn this cohort study of patients with PKU from multiple centers, the implementation of the reimbursement policy for special foods was associated with controlling the blood PHE concentration. Special foods expenditure for patients with PKU should be included in the scope of long-term social medical insurance reimbursement.

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Dietary protein and protein substitute requirements in adults with phenylketonuria: A review of the clinical guidelines

Cited by 15 publications

References 40 publications

Dietetic Management of Adults with Phenylketonuria (PKU) in the UK: A Care Consensus Document

Dietetic Management of Adults with Phenylketonuria (PKU) in the UK: A Care Consensus Document

Protein status of people with phenylketonuria: a scoping review protocol

Insurance Reimbursement for Special Foods and Phenylalanine Levels in Patients With PKU in China

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