Effects of long-term microgravity exposure on cancellous and cortical weight-bearing bones of cosmonauts

Vico, Laurence; Collet, Philippe; Guignandon, Alain; Lafage-Proust, Marie-Hélène; Thomas, Thierry; Rehaïlia, M.; Alexandre, Christian

doi:10.1016/s0140-6736(00)02217-0

Cited by 652 publications

(446 citation statements)

References 14 publications

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“…Studies using calcium kinetics, site-specific bone densitometry and bone turnover markers document a net loss of bone mineral in the gravitationally-unloaded skeleton of crew members who had flown either on Skylab (28, 56 and 84 days) or on long-duration missions (>4 months) aboard the Russian Mir spacecraft and the International Space Station (ISS) [2][3][4][5][6][7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

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Recovery of spaceflight-induced bone loss: Bone mineral density after long-duration missions as fitted with an exponential function

Sibonga

Evans

Sung

et al. 2007

Bone

191

106

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The loss of bone mineral in NASA astronauts during spaceflight has been investigated throughout the more than 40 years of space travel. Consequently, it is a medical requirement at NASA Johnson Space Center (JSC) that changes in bone mass be monitored in crew members by measuring bone mineral density (BMD) with dual-energy x-ray absorptiometry (DXA) before and after flight on astronauts who serve on long-duration missions (4-6 months). We evaluated this repository of medical data to track whether there is recovery of bone mineral that was lost during spaceflight.Our analysis was supplemented by BMD data from cosmonauts (by convention, a space traveler formally employed by the Russia Aviation and Space Agency or by the previous Soviet Union) who had also flown on long-duration missions. Data from a total of 45 individual crew members -a small number of whom flew on more than one mission -were used in this analysis.Changes in BMD (between 56 different sets of pre-and postflight measurements) were plotted as a function of time (days after landing). Plotted BMD changes were fitted to an exponential mathematical function that estimated: i) BMD change on landing day (day 0) and ii) the number of days after landing when 50% of the lost bone would be recovered ("50% recovery time") in the lumbar spine, trochanter, pelvis, femoral neck and calcaneus. In sum, averaged losses of bone mineral after long-duration spaceflight ranged between 2-9% across all sites with our recovery model predicting a 50% restoration of bone loss for all sites to be within 9 months.Recovery of spaceflight-induced bone loss 3

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Section: Introductionmentioning

confidence: 99%

“…Since the Skylab missions of the 1970's, measurements of bone mineral and bone mineral density had been used to evaluate the effects of spaceflight on the skeleton [4,5,8,9]. More recently, QCT scans of long-duration crew members was used to evaluate changes in mineral density and in hip structure after spaceflight [10].…”

Section: Introductionmentioning

confidence: 99%

Recovery of spaceflight-induced bone loss: Bone mineral density after long-duration missions as fitted with an exponential function

Sibonga

Evans

Sung

et al. 2007

Bone

191

106

View full text Add to dashboard Cite

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“…Data from Skylab and Mir missions show that astronauts continue to lose bone despite participation in vigorous in-flight exercise protocols [11,26,35,41]. The inflight exercise program on early International Space Station (ISS) flights was also not successful at mitigating weightlessness-induced bone loss [25], although exercise hardware availability in those missions was inconsistent.…”

Section: Introductionmentioning

confidence: 99%

Lower body negative pressure treadmill exercise as a countermeasure for bed rest-induced bone loss in female identical twins

Zwart

Hargens

Lee

et al. 2007

Bone

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Supine weight-bearing exercise within lower body negative pressure (LBNP) alleviates some of the skeletal deconditioning induced by simulated weightlessness in men. We examined the potential beneficial effect in women. Because dietary acid load affected the degree of bone resorption in men during bed rest, we also investigated this variable in women. Subjects were 7 pairs of female identical twins assigned at random to 2 groups, sedentary bed rest (control) or bed rest with supine treadmill exercise within LBNP. Dietary intake was controlled and monitored. Urinary calcium and markers of bone resorption were measured before bed rest (BR) and on BR days 5/6, 12/13, 19/20, and 26/27. Bone mineral content was assessed by dual-energy X-ray absorptiometry before and after bed rest. Data were analyzed by repeated measures two-way analysis of variance. Pearson correlation coefficients were used to define the relationships between diet and markers of bone metabolism, and to estimate heritability of markers. During bed rest, all markers of bone resorption and urinary calcium and phosphorus increased (P < 0.001); parathyroid hormone (P = 0.06), bone-specific alkaline phosphatase (P = 0.06), and 1,25-dihydroxyvitamin D (P = 0.09) tended to decrease. LBNP exercise tended to mitigate bone density loss. The ratio of dietary animal protein to potassium was positively correlated with urinary calcium excretion for all weeks of bed rest in the control group, but only during weeks 1 and 3 for the exercise group. Pre-bed rest data suggested that many markers of bone metabolism have strong genetic determinants. Treadmill exercise within LBNP had less of a protective effect on bone resorption during bed rest in women than previously-published results had Sources of support: This study was funded by NASA through grant NAG 9-1425 and by NIH through grant GCRC M01-RR00827 to UCSD.Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. shown for its effect in men, but the same trends were observed for both sexes. Dietary acid load of these female subjects was significantly correlated with calcium excretion but not with other bone resorption markers. NIH Public Access

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“…1 ± 3 The loss of bone mineral from the skeleton has been di cult to counter in microgravitational environments, such as spinal cord injury, 4 ± 7 bedrest, 8 ± 10 and space¯ight. 11,12 Under these conditions the loss of bone mass is more pronounced in the lower, weight-bearing, limbs and remains relatively unchanged in the trunk. In spinal cord injured (SCI) however, demineralisation is also in¯uenced by the level and completeness of the spinal cord lesion, and duration of injury (DOI).…”

Section: Introductionmentioning

confidence: 99%

“…21 ± 23 However, results of load-bearing exercise in a microgravitational environment have been equivocal. 11,12,20,21,24,25 The purpose of this study was to compare bone mineral density of the total body, upper limbs, lower limbs, hip, and spine regions in a group of very active spinal cord injured adult males with values obtained in active able-bodied controls, carefully matched for age, height, and weight.…”

Section: Introductionmentioning

confidence: 99%

Intensive exercise may preserve bone mass of the upper limbs in spinal cord injured males but does not retard demineralisation of the lower body

2002

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Study design: Cross-sectional study comparing a group of active spinal cord injured (SCI) males carefully matched for age, height, and weight with active able-bodied male controls. Objectives: To compare bone mass of the total body, upper and lower limbs, hip, and spine regions in active SCI and able-bodied individuals. Setting: Outpatient study undertaken in two centres in New Zealand. Methods: Dual energy X-ray absorptiometry (DEXA) scanning was used to determine bone mass. Questionnaires were used to ascertain total time spent in weekly physical activity for each individual. The criterion for entry into the study was regular participation in physical activity of more than 60 min per week, over and above that required for rehabilitation. Results: Seventeen SCI and their able-bodied controls met our required activity criterion. Bone mineral density (BMD) values of the total body and hip regions were signi®cantly lower in the SCI group than in their controls (P=0.0001). Leg BMD and bone mineral content (BMC) were also signi®cantly lower in the SCI group (P=0.0001). By contrast, lumbar spine BMD and arm BMD and BMC did not di er between the SCI and control groups. Arm BMD and BMC were greater (not signi®cant) than the reference norms (LUNAR database) for both groups.

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Effects of long-term microgravity exposure on cancellous and cortical weight-bearing bones of cosmonauts

Cited by 652 publications

References 14 publications

Recovery of spaceflight-induced bone loss: Bone mineral density after long-duration missions as fitted with an exponential function

Recovery of spaceflight-induced bone loss: Bone mineral density after long-duration missions as fitted with an exponential function

Lower body negative pressure treadmill exercise as a countermeasure for bed rest-induced bone loss in female identical twins

Intensive exercise may preserve bone mass of the upper limbs in spinal cord injured males but does not retard demineralisation of the lower body

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