Forskning
Udskriv Udskriv
Switch language
Region Hovedstaden - en del af Københavns Universitetshospital
Udgivet

Impact of habituated dietary protein intake on fasting and postprandial whole-body protein turnover and splanchnic amino acid metabolism in elderly men: a randomized, controlled, crossover trial

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

DOI

  1. Prior undernutrition and insulin production several years later in Tanzanian adults

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  2. Liraglutide after diet-induced weight loss for pain and weight control in knee osteoarthritis: a randomized controlled trial

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  3. Higher habitual flavonoid intakes are associated with a lower risk of peripheral artery disease hospitalizations

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  4. Associations of childhood BMI and change in BMI from childhood to adulthood with risks of hypertensive disorders in pregnancy

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Vis graf over relationer

BACKGROUND: Efficacy of protein absorption and subsequent amino acid utilization may be reduced in the elderly. Higher protein intakes have been suggested to counteract this.

OBJECTIVES: We aimed to elucidate how habituated amounts of protein intake affect the fasted state of, and the stimulatory effect of a protein-rich meal on, protein absorption, whole-body protein turnover, and splanchnic amino acid metabolism.

METHODS: Twelve men (65-70 y) were included in a double-blinded crossover intervention study, consisting of a 20-d habituation period to a protein intake at the RDA or a high amount [1.1 g · kg lean body mass (LBM)-1 · d-1 or >2.1 g · kg LBM-1 · d-1, respectively], each followed by an experimental trial with a primed, constant infusion of D8-phenylalanine and D2-tyrosine. Arterial and hepatic venous blood samples were obtained after an overnight fast and repeatedly 4 h after a standardized meal including intrinsically labeled whey protein concentrate and calcium-caseinate proteins. Blood was analyzed for amino acid concentrations and phenylalanine and tyrosine tracer enrichments from which whole-body and splanchnic amino acid and protein kinetics were calculated.

RESULTS: High (compared with the recommended amount of) protein intake resulted in a higher fasting whole-body protein turnover with a resultant mean ± SEM 0.03 ± 0.01 μmol · kg LBM-1 · min-1 lower net balance (P < 0.05), which was not rescued by the intake of a protein-dense meal. The mean ± SEM plasma protein fractional synthesis rate was 0.13 ± 0.06%/h lower (P < 0.05) after habituation to high protein. Furthermore, higher fasting and postprandial amino acid removal were observed after habituation to high protein, yielding higher urea excretion and increased phenylalanine oxidation rates (P < 0.01).

CONCLUSIONS: Three weeks of habituation to high protein intake (>2.1 g protein · kg LBM-1 · d-1) led to a significantly higher net protein loss in the fasted state. This was not compensated for in the 4-h postprandial period after intake of a meal high in protein.This trial was registered at clinicaltrials.gov as NCT02587156.

OriginalsprogEngelsk
TidsskriftThe American journal of clinical nutrition
Vol/bind112
Udgave nummer6
Sider (fra-til)1468-1484
Antal sider17
ISSN0002-9165
DOI
StatusUdgivet - 10 dec. 2020

Bibliografisk note

Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.

ID: 61569102