Effects of artificial gravity during bed rest on bone metabolism in humans.

We report results from a study designed to explore the utility of artificial gravity (AG) as a countermeasure to bone loss induced by microgravity simulation. After baseline testing, 15 male subjects underwent 21 days of 6 degrees head-down bed rest to simulate the deconditioning associated with spaceflight. Eight of the subjects underwent 1 h of centrifugation (AG; 1 G(z) at the heart, 2.5 G(z) at the feet) each day for 21 days, whereas seven of the subjects served as untreated controls (Con). Blood and urine were collected before, during, and after bed rest for bone marker determinations. Bone mineral density (BMD) and bone mineral content (BMC) were determined by dual-energy X-ray absorptiometry and peripheral quantitative computerized tomography before and after bed rest. Urinary excretion of bone resorption markers increased during bed rest, but the AG and Con groups did not differ significantly. The same was true for serum C-telopeptide. During bed rest, bone alkaline phosphatase (ALP) and total ALP tended to be lower in the AG group (P = 0.08, P = 0.09). Neither BMC nor BMD changed significantly from the pre-bed rest period in AG or Con groups, and the two groups were not significantly different. However, when AG and Con data were combined, there was a significant (P < 0.05) effect of time for whole body total BMC and total hip and trochanter BMD. These data failed to demonstrate efficacy of this AG prescription to prevent the changes in bone metabolism observed during 3 wk of bed rest.

[1]  W H Paloski,et al.  Effects of 21 days of bed rest, with or without artificial gravity, on nutritional status of humans. , 2009, Journal of applied physiology.

[2]  Scott M Smith,et al.  Nutritional status assessment before, during, and after long-duration head-down bed rest. , 2009, Aviation, space, and environmental medicine.

[3]  M. Eliasziw,et al.  Meta-analysis of the quantity of calcium excretion associated with the net acid excretion of the modern diet under the acid-ash diet hypothesis. , 2008, The American journal of clinical nutrition.

[4]  Martina Heer,et al.  WISE-2005: supine treadmill exercise within lower body negative pressure and flywheel resistive exercise as a countermeasure to bed rest-induced bone loss in women during 60-day simulated microgravity. , 2008, Bone.

[5]  M. Narici,et al.  From space to Earth: advances in human physiology from 20 years of bed rest studies (1986–2006) , 2007, European Journal of Applied Physiology.

[6]  Thomas S Richardson,et al.  Rest-inserted loading rapidly amplifies the response of bone to small increases in strain and load cycles. , 2007, Journal of applied physiology.

[7]  Scott M Smith,et al.  Lower body negative pressure treadmill exercise as a countermeasure for bed rest-induced bone loss in female identical twins. , 2007, Bone.

[8]  Subburaman Mohan,et al.  Global gene expression analysis in the bones reveals involvement of several novel genes and pathways in mediating an anabolic response of mechanical loading in mice , 2005, Journal of cellular biochemistry.

[9]  Christopher R Jacobs,et al.  Effects of short-term recovery periods on fluid-induced signaling in osteoblastic cells. , 2005, Journal of biomechanics.

[10]  M. Mukhida,et al.  Mechanical loading modulates glutamate receptor subunit expression in bone. , 2005, Bone.

[11]  R. Gerzer,et al.  Immobilization induces a very rapid increase in osteoclast activity. , 2005, Acta astronautica.

[12]  R. Wolfe,et al.  Amino acid supplementation alters bone metabolism during simulated weightlessness. , 2005, Journal of applied physiology.

[13]  C. Steele,et al.  Influence of increased mechanical loading by hypergravity on the microtubule cytoskeleton and prostaglandin E2 release in primary osteoblasts. , 2005, American journal of physiology. Cell physiology.

[14]  Ronald F Zernicke,et al.  Strain rate influences periosteal adaptation in mature bone. , 2005, Medical engineering & physics.

[15]  Scott M Smith,et al.  The nutritional status of astronauts is altered after long-term space flight aboard the International Space Station. , 2005, The Journal of nutrition.

[16]  Scott M Smith,et al.  Bone Markers, Calcium Metabolism, and Calcium Kinetics During Extended‐Duration Space Flight on the Mir Space Station , 2004, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[17]  Hiroshi Ohshima,et al.  Intravenous Pamidronate Prevents Femoral Bone Loss and Renal Stone Formation During 90‐Day Bed Rest , 2004, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[18]  Scott M Smith,et al.  The ratio of animal protein intake to potassium intake is a predictor of bone resorption in space flight analogues and in ambulatory subjects. , 2004, The American journal of clinical nutrition.

[19]  H. Akima,et al.  Effect of centrifuge-induced artificial gravity and ergometric exercise on cardiovascular deconditioning, myatrophy, and osteoporosis induced by a -6 degrees head-down bedrest. , 2004, Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology.

[20]  Daniel L. Feeback,et al.  Resistance exercise as a countermeasure to disuse-induced bone loss. , 2004, Journal of applied physiology.

[21]  H. Genant,et al.  Cortical and Trabecular Bone Mineral Loss From the Spine and Hip in Long‐Duration Spaceflight , 2004, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[22]  F. Naumann,et al.  Changes in cervical spine bone mineral density in response to flight training. , 2004, Aviation, space, and environmental medicine.

[23]  J. Davis-Street,et al.  Variability of Collagen Crosslinks: Impact of Sample Collection Period , 2004, Calcified Tissue International.

[24]  Sundar Srinivasan,et al.  Why Rest Stimulates Bone Formation: A Hypothesis Based on Complex Adaptive Phenomenon , 2004, Exercise and sport sciences reviews.

[25]  Scott M Smith,et al.  Evaluation of Treadmill Exercise in a Lower Body Negative Pressure Chamber as a Countermeasure for Weightlessness‐Induced Bone Loss: A Bed Rest Study With Identical Twins , 2003, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[26]  Martina Heer,et al.  Bone resorption is induced on the second day of bed rest: results of a controlled crossover trial. , 2003, Journal of applied physiology.

[27]  Biao Sun,et al.  Effectiveness of intermittent -Gx gravitation in preventing deconditioning due to simulated microgravity. , 2003, Journal of applied physiology.

[28]  M. Delp,et al.  Site- and compartment-specific changes in bone with hindlimb unloading in mature adult rats. , 2002, Bone.

[29]  A. Sebastian,et al.  Potassium citrate prevents increased urine calcium excretion and bone resorption induced by a high sodium chloride diet. , 2002, The Journal of clinical endocrinology and metabolism.

[30]  J. Wark,et al.  The effects of +Gz force on the bone mineral density of fighter pilots. , 2001, Aviation, space, and environmental medicine.

[31]  G. Horneck,et al.  Microgravity inhibits intestinal calcium absorption as shown by a stable strontium test , 2000, European journal of clinical investigation.

[32]  A LeBlanc,et al.  Bone mineral and lean tissue loss after long duration space flight. , 2000, Journal of musculoskeletal & neuronal interactions.

[33]  J. Vernikos,et al.  Dietary salt and urinary calcium excretion in a human bed rest spaceflight model. , 2000, Aviation, space, and environmental medicine.

[34]  L. Suva,et al.  Microgravity: a Possible Mechanism for Bone Remodeling Alterations in Skeletal Perfusion with Simulated , 2022 .

[35]  M Heer,et al.  Space flight is associated with rapid decreases of undercarboxylated osteocalcin and increases of markers of bone resorption without changes in their circadian variation: observations in two cosmonauts. , 2000, Clinical chemistry.

[36]  T. Takano-Yamamoto,et al.  Molecular events caused by mechanical stress in bone. , 2000, Matrix biology : journal of the International Society for Matrix Biology.

[37]  M E Wastney,et al.  Calcium metabolism before, during, and after a 3-mo spaceflight: kinetic and biochemical changes. , 1999, American journal of physiology. Regulatory, integrative and comparative physiology.

[38]  Scott M Smith,et al.  Collagen cross-link excretion during space flight and bed rest. , 1998, The Journal of clinical endocrinology and metabolism.

[39]  M. Orth,et al.  Cortical bone responses to 2G hypergravity in growing rats. , 1998, Aviation, space, and environmental medicine.

[40]  M. Lafage-Proust,et al.  Bone formation and resorption biological markers in cosmonauts during and after a 180-day space flight (Euromir 95). , 1998, Clinical chemistry.

[41]  D. Burr,et al.  Mechanotransduction in bone: osteoblasts are more responsive to fluid forces than mechanical strain. , 1997, The American journal of physiology.

[42]  J Vernikos,et al.  Effect of standing or walking on physiological changes induced by head down bed rest: implications for spaceflight. , 1996, Aviation, space, and environmental medicine.

[43]  C. Turner,et al.  Mechanotransduction and the functional response of bone to mechanical strain , 1995, Calcified Tissue International.

[44]  C. Turner,et al.  Skeletal adaptations to mechanical usage: results from tibial loading studies in rats. , 1995, Bone.

[45]  A Heinonen,et al.  Bone mineral density in female athletes representing sports with different loading characteristics of the skeleton. , 1995, Bone.

[46]  J. Booth,et al.  Resampling-Based Multiple Testing. , 1994 .

[47]  A. Parfitt.  Bone effects of space flight: analysis by quantum concept of bone remodelling. , 1981, Acta astronautica.

[48]  J. Oyama,et al.  Effect of chronic centrifugation on bone density of the rat , 1977, Anatomy and Embryology.

[49]  J. Nickl,et al.  Untersuchungen über transport-reaktionen in salzschmelzen II. Isothermes system: Metalle ohne Kontakt , 1977 .

[50]  P. C. Rambaut,et al.  Effect of weightlessness on mineral metabolism; Metabolic studies on skylab orbital space flights , 1975, Calcified Tissue Research.

[51]  G. Fosse,et al.  Bone atrophy and hypergravity in mice. , 1974, Growth.

[52]  O. Castagna,et al.  Bubble formation and endothelial function before and after 3 months of dive training. , 2009, Aviation, space, and environmental medicine.

[53]  A. Leblanc,et al.  Skeletal responses to space flight and the bed rest analog: a review. , 2007, Journal of musculoskeletal & neuronal interactions.

[54]  G. Block,et al.  Nutrititional Status Assessment of International Space Station Crew Members , 2005 .

[55]  Daniel L. Feeback,et al.  Alendronate as an effective countermeasure to disuse induced bone loss. , 2002, Journal of musculoskeletal & neuronal interactions.

[56]  Helen W. Lane,et al.  Nutrition in spaceflight and weightlessness models , 2000 .

[57]  R. Dillaman,et al.  Bone growth and calcium balance during simulated weightlessness in the rat. , 1990, Journal of applied physiology.

[58]  P. C. Rambaut,et al.  Mineral and Nitrogen Metabolic Studies, Experiment M071 , 1977 .

[59]  P. Rambaut,et al.  Bone mineral measurement: Experiment M078 , 1977 .

[60]  J. Oyama.  Response and adaptation of beagle dogs to hypergravity. , 1975, Life sciences and space research.