Biochemical parameters of bone turnover during ten days of bed rest and subsequent mobilization

Wiel, H.E. van der; Lips, Paul; Nauta, J. J. P.; Netelenbos, J. C.; Hazenberg, G. J.

doi:10.1016/0169-6009(91)90079-f

Cited by 76 publications

(36 citation statements)

References 19 publications

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“…Trends toward increased levels of bone resorption markers are consistent with previous studies [8,10,11]. Our results also agree with earlier histomorphometric data from iliac crest biopsies showing an increased number of both osteoclasts and active resorption surfaces after a 4-month HDT bedrest [3,44].…”

Section: Discussionsupporting

confidence: 95%

“…Some drug trials were attempted to counteract the effects of bedrest unloading [2,3]. Since 1980, bedrest of normal subjects has been used for skeletal studies extending from 7 to 360 days with the use of investigation tools such as quantitative X-rays, bone densitometry and biochemical markers [4][5][6][7][8][9][10][11]. The major aim of using the bedrest model, either horizontal or with head-down tilt (HDT), is the earth-based simulation of a microgravity environment to study its effects on various biological systems and to test countermeasures aimed at preventing or decreasing its deleterious consequences [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

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Modifications of Bone and Connective Tissue after Orthostatic Bedrest

Uebelhart

Bernard

Hartmann

et al. 2000

Osteoporosis International

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Eight male volunteers were submitted to a 6-week anti-orthostatic bedrest trial followed by a 1-month reambulation period. We prospectively monitored whole-body composition by dual-energy X-ray absorptiometry, bone and connective tissue metabolism by biochemical markers and calcium regulating hormones by 1-84 parathyroid hormone and 1,25-dihydroxyvitamin D(3). Bone mineral density (BMD) did not vary significantly; however, a trend toward an increase in head BMD and a decrease in trunk, lumbar vertebrae and lower limb BMD was observed. A decrease in the lower limb lean content occurred by day 27 and was maximum by day 42 after the beginning of bedrest; it normalized by day 30 after bedrest. The serum levels of both osteocalcin and C-terminal crosslinked telopeptide of type I collagen increased as a consequence of bedrest. A slight increase in the serum levels of the N-terminal propeptide of type III collagen, a marker of connective tissue metabolism, was observed during the bedrest period. Except for the C-terminal extension propeptide of type I collagen, all markers decreased to baseline pre-immobilization levels during the 1-month recovery phase. Serum PTH and 1,25-dihydroxyvitamin D(3) levels were low during the bedrest period and rose during the reambulation phase. These results seem to reflect early changes in bone and connective tissue metabolism as a result of bedrest unloading, but their order of magnitude remains moderate, thus emphasizing the necessity to perform longer-duration trials.

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Section: Discussionsupporting

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Modifications of Bone and Connective Tissue after Orthostatic Bedrest

Uebelhart

Bernard

Hartmann

et al. 2000

Osteoporosis International

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“…In addition, the choice of assay method is important because an assay could detect both PTH fragments and intact molecules (56). Currently, the most commonly used assays detect the 7-84 portion of the molecule as well as intact PTH (57).…”

Section: Plasma Parathyroid Hormone Concentrationmentioning

confidence: 99%

“…However, the plasma PTH concentration varies widely within and among individuals at any given concentration of 25(OH)D (46,47) because the plasma PTH concentration depends on many factors other than vitamin D status, such as stage of life, ethnic background, dietary calcium and phosphorus intakes, time of day, kidney function, physical inactivity, and drug use (16,(52)(53)(54)(55)(56). In addition, the choice of assay method is important because an assay could detect both PTH fragments and intact molecules (56).…”

Section: Plasma Parathyroid Hormone Concentrationmentioning

confidence: 99%

Vitamin D across the lifecycle: physiology and biomarkers

Prentice

Goldberg

Schoenmakers

2008

The American Journal of Clinical Nutrition

218

165

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The field of vitamin D public health research has a pressing need to define sensitive and specific predictors of vitamin D status that can be used to determine whether an individual or population has a supply of vitamin D that is sufficient to meet requirements. The aim of this review is to highlight the considerations needed when evaluating evidence of the relations between vitamin D biomarkers and functional or health outcomes across the life cycle. It draws attention to the importance of distinguishing between biomarkers of supply, function, and outcome and of considering the many factors that could influence interpretation, such as life stage, ethnicity, body mass index, liver and kidney function, and dietary calcium and phosphorus intake. The vitamin D biomarkers that have shown the most utility to date are the plasma concentration of 25-hydroxyvitamin D (supply), the plasma concentration of parathyroid hormone (function), and the presence or absence of rickets (outcome). However, a single biomarker of vitamin D status or threshold value is unlikely to be valid in all situations. The field therefore needs research to refine existing biomarkers or establish new indicators that take the many factors into account and to identify useful functional biomarkers of vitamin D status for infants, children, women of reproductive age, and specific ethnic groups. However, evidence using the biomarkers currently available shows that frank vitamin D deficiency is a major public health problem in many parts of the world that requires urgent attention.Am J Clin Nutr 2008;88(suppl):500S-6S.

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“…Total alkaline phosphatase did not vary during the immobilisation period. 36 Pedersen et al evaluated serum levels of carboxy terminal propeptide of type I collagen (PICP) and osteocalcin as well as urinary deoxy-pyridinoline (D-Pyr) in nine young women before and after 5 days of complete bed rest. Bed rest resulted in a 14% decrease in serum PICP accompanied by a fade in normal circadian rythm after 5 days of immobilisation.…”

Section: Bone Metabolism After Loss Of Normal Biomechanical Functionmentioning

confidence: 99%

Bone metabolism in spinal cord injured individuals and in others who have prolonged immobilisation. A review

et al. 1995

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Immobilisation or disuse is a condition known to be associated with a decrease in bone mass, osteopenia and in some people leading to osteoporosis with an increased risk of fractures. In this condition, previous histomorphometric and biochemical reports have shown an uncoupling between bone formation and resorption, but the exact sequence of the events resulting in bone loss is still not fully understood. In spinal cord injury for instance, the main finding soon after the onset is decreased osteoblastic activity associated with a dramatic increase in bone degradation. The overall consequence of these metabolic events is the development of a rapid and severe osteoporosis only observed in the paralysed part of the body associated with the loss of biomechanical strength and the biosynthesis of a structurally modified matrix which is unable to sustain normal mechanical stress. This situation dramatically increases the risk of fractures. The same uncoupling phenomenon has been described in healthy individuals who have been submitted to long duration bedrest and also in astronauts during spaceflight; but the timing, intensity and the metabolic subset may be different as these people do recover after cessation of the disuse period, which does not occur in paralysed patients. As new accurate and sensitive non-invasive techniques have become available recently to assess bone and connective tissue metabolism, more information is now available regarding bone loss in paralysed and/or immobilised individuals. These techniques should be definitely helpful in orientating new therapeutic trials with drugs and/or procedures intended to correct the musculoskeletal deleterious effects of disuse. This paper is therefore aimed at a review of bone metabolism in those with a severe spinal cord injury, or with a long duration of bedrest, or with loss of biomechanical function, or with actual or simulated spaceflight, in all instances using non-invasive techniques.

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Biochemical parameters of bone turnover during ten days of bed rest and subsequent mobilization

Cited by 76 publications

References 19 publications

Modifications of Bone and Connective Tissue after Orthostatic Bedrest

Modifications of Bone and Connective Tissue after Orthostatic Bedrest

Vitamin D across the lifecycle: physiology and biomarkers

Bone metabolism in spinal cord injured individuals and in others who have prolonged immobilisation. A review

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