Bone formation and resorption biological markers in cosmonauts during and after a 180-day space flight (Euromir 95).
Long-term spaceflights induce bone loss as a result of profound modifications of bone remodeling, the modalities of which remain unknown in humans. We measured intact parathyroid hormone (PTH) and serum calcium; for bone formation, serum concentrations of bone alkaline phosphatase (BAP), intact osteocalcin (iBGP), and type 1 procollagen propeptide (PICP); for resorption, urinary concentrations (normalized by creatinine) of procollagen C-telopeptide (CTX), free and bound deoxypyridinoline (F and B D-Pyr), and Pyr in a 36-year-old cosmonaut (RTO), before (days -180, -60, and -15), during (from days 10 to 178, n = 12), and after (days +7, +15, +25, and +90) a 180-day spaceflight, in another cosmonaut (ASW) before and after the flight. Flight PTH tended to decrease by 48% and postflight PTH increased by 98%. During the flight, BAP, iBGP, and PICP decreased by 27%, 38%, and 28% respectively in CM1, and increased by 54%, 35%, and 78% after the flight. F D-Pyr and CTX increased by 54% and 78% during the flight and decreased by 29% and 40% after the flight, respectively. We showed for the first time in humans that microgravity induced an uncoupling of bone remodeling between formation and resorption that could account for bone loss.
Caillot-Augusseau
A
A
Laboratoire de Biologie du Tissu Osseux, Faculté de Médecine, Saint Etienne, France.
Lafage-Proust
M H
MH
Soler
C
C
Pernod
J
J
Dubois
F
F
Alexandre
C
C
D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D000596:Amino Acids / Q000652:urine; D018480:Astronauts; D015415:Biomarkers / Q000097:blood* / Q000652:urine; D001846:Bone Development; D001862:Bone Resorption / Q000097:blood* / Q000209:etiology / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003404:Creatinine / Q000652:urine; D005060:Europe; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007118:Immunoassay / Q000379:methods; D015592:Immunoradiometric Assay; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood / Q000652:urine; D012016:Reference Values; D013026:Space Flight; D013997:Time Factors
D000596:Amino Acids; D015415:Biomarkers; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D011347:Procollagen; C042813:procollagen type I carboxy terminal peptide; D015675:Osteocalcin; C015484:pyridinoline; C036020:deoxypyridinoline; D003404:Creatinine; D000469:Alkaline Phosphatase; D006854:Hydrocortisone