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KHCO3 Prevents Increase in Bone Resorption with High Protein in Bed Rest (MEP Study)
Author(s) -
Heer Martina,
Buehlmeier Judith,
Smith Scott M.,
Baecker Natalie,
FringsMeuthen Petra
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.615.15
Subject(s) - bone resorption , endocrinology , medicine , resorption , chemistry , bed rest , bone remodeling , acidosis , n terminal telopeptide , alkaline phosphatase , osteocalcin , biochemistry , enzyme
Protein supplementation in bed rest may increase protein synthesis, but it also increases bone resorption, likely mediated by low‐grade metabolic acidosis. To test the hypothesis that providing KHCO3 with whey protein (WP) will prevent the increase in bone resorption that results from WP alone, we conducted a crossover study with 9 healthy male subjects (age 31±6 y, body mass [BM] 77±7 kg). In both study phases, following a 7‐d ambulatory period, subjects participated in 21‐d of ‐6° head‐down tilt bed rest. Diet was standardized across phases. In the control phase, subjects received no supplements. In the intervention phase, they received 6 doses per day of 0.6 g WP/kg BM together with 15 mmol KHCO3. WP was added to the nominal dietary protein, isocalorically (i.e., fat and CHO reduced). HDBR led to an increase in excretion of bone resorption markers C‐ (CTX) and N‐telopeptide (NTX) by 85±28% (p<0.001) and 35±19% (p<0.001), respectively. WP/KHCO3 prevented an additional rise of these markers. The bone formation marker procollagen‐I‐N‐terminal propeptide was increased (p=0.02) with WP/KHCO3, while bone alkaline phosphatase was unchanged. We conclude that increased bone resorption from high protein intake during bed rest can be mitigated by KHCO3. Funded by the DLR Space Program.