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Effects of high-protein intake on bone turnover in long-term bed rest in women

Heer, Martina and Baecker, Natalie and Frings-Meuthen, Petra and Graf, Sebastian and Zwart, S. and Biolo, G. and Smith, S.M. (2017) Effects of high-protein intake on bone turnover in long-term bed rest in women. Applied Physiology, Nutrition, and Metabolism, 42 (5), pp. 537-546. NRC Research Press. DOI: 10.1139/apnm-2016-0292 ISSN 1715-5312

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Official URL: https://www.ncbi.nlm.nih.gov/pubmed/28177714

Abstract

Bed rest (BR) causes bone loss, even in otherwise healthy subjects. Several studies suggest that ambulatory subjects may benefit from high-protein intake to stimulate protein synthesis and to maintain muscle mass. However, increasing protein intake above the recommended daily intake without adequate calcium and potassium intake may increase bone resorption. We hypothesized that a regimen of high-protein intake (HiPROT), applied in an isocaloric manner during BR, with calcium and potassium intake meeting recommended values, would prevent any effect of BR on bone turnover. After a 20-day ambulatory adaptation to a controlled environment, 16 women participated in a 60-day, 6° head-down-tilt (HDT) BR and were assigned randomly to 1 of 2 groups. Control (CON) subjects (n = 8) received 1 g/(kg body mass·day)-1 dietary protein. HiPROT subjects (n = 8) received 1.45 g protein/(kg body mass·day)-1 plus an additional 0.72 g branched-chain amino acids per day during BR. All subjects received an individually tailored diet (before HDTBR: 1888 ± 98 kcal/day; during HDTBR: 1604 ± 125 kcal/day; after HDTBR: 1900 ± 262 kcal/day), with the CON group's diet being higher in fat and carbohydrate intake. High-protein intake exacerbated the BR-induced increase in bone resorption marker C-telopeptide (>30%) (p < 0.001) by the end of BR. Bone formation markers were unaffected by BR and high-protein intake. We conclude that high-protein intake in BR might increase bone loss. Further long-duration studies are mandatory to show how the positive effect of protein on muscle mass can be maintained without the risk of reducing bone mineral density.

Item URL in elib:https://elib.dlr.de/118840/
Document Type:Article
Title:Effects of high-protein intake on bone turnover in long-term bed rest in women
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Heer, MartinaMartina.Heer (at) dlr.deUNSPECIFIED
Baecker, NatalieNatalie.Baecker (at) dlr.deUNSPECIFIED
Frings-Meuthen, PetraPetra.Frings-Meuthen (at) dlr.deUNSPECIFIED
Graf, SebastianSebastian.Graf (at) dlr.deUNSPECIFIED
Zwart, S.NASAUNSPECIFIED
Biolo, G.UNSPECIFIEDUNSPECIFIED
Smith, S.M.UNSPECIFIEDUNSPECIFIED
Date:19 January 2017
Journal or Publication Title:Applied Physiology, Nutrition, and Metabolism
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:42
DOI :10.1139/apnm-2016-0292
Page Range:pp. 537-546
Publisher:NRC Research Press
ISSN:1715-5312
Status:Published
Keywords:acides aminés à chaîne ramifiée; apport riche en protéines; bed rest; bone turnover; branched chained amino acids; high-protein intake; renouvellement osseux; repos alité
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Research under Space Conditions
DLR - Research area:Raumfahrt
DLR - Program:R FR - Forschung unter Weltraumbedingungen
DLR - Research theme (Project):R - Vorhaben Systemphysiologie
Location: Köln-Porz
Institutes and Institutions:Institute of Aerospace Medicine > Muscle and Bone Metabolism
Deposited By: Polak, Agnieszka
Deposited On:08 Feb 2018 13:12
Last Modified:01 Dec 2018 19:53

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