NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Prevention of hypercalciuria and stone-forming propensity during prolonged bedrest by alendronateThe bone loss and hypercalciuria induced by immobilization or the decreased gravitational forces of space are well described. Using a model of bedrest immobilization, the ability of a potent aminobisphosphonate, alendronate, to avert hypercalciuria and stone-forming propensity was tested. Sixteen male subjects participated in a randomized, placebo-controlled trial in which they received either 20 mg of alendronate or placebo 2 weeks prior to and during 3 weeks of strict bedrest. Parameters of bone and calcium metabolism and urinary crystallization of stone-forming salts were measured before and at the end of bedrest. In the placebo group, bedrest increased urinary calcium (209 +/- 47 to 267 +/- 60 mg/day, p < 0.01) and the saturation of calcium phosphate. Before bedrest, the alendronate group had a significantly lower serum calcium (8.8 +/- 0.4 vs. 9.6 +/- 0.5 mg/dl, p < 0.01) and higher serum PTH (62.4 +/- 33.1 vs. 23.1 +/- 7.5 pg/ml, p < 0.01) compared with the placebo group. Moreover, the alendronate group had a lower urinary calcium (75 +/- 41 mg/day) and saturation of calcium oxalate and calcium phosphate. These effects of alendronate were sustained during bedrest. Following bedrest in the alendronate group, urinary calcium rose to 121 +/- 50 mg/day, a value less than that in the placebo group before or during bedrest. Similarly, urinary saturation of calcium oxalate and calcium phosphate rose with bedrest in the alendronate-treated patients but remained lower than values obtained in placebo-treated patients before or during bedrest. Alendronate inhibits bone mineral loss and averts the hypercalciuria and increased propensity for the crystallization of stone-forming calcium salts which occurs during 3 weeks of strict bedrest.
Document ID
20050000211
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Ruml, L. A.
(University of Texas Southwestern Medical Center Dallas, United States)
Dubois, S. K.
Roberts, M. L.
Pak, C. Y.
Date Acquired
August 22, 2013
Publication Date
April 1, 1995
Publication Information
Publication: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research
Volume: 10
Issue: 4
ISSN: 0884-0431
Subject Category
Aerospace Medicine
Funding Number(s)
CONTRACT_GRANT: M01-RR00633
CONTRACT_GRANT: P01-DK20543
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Program Space Physiology and Countermeasures
NASA Discipline Regulatory Physiology
NASA Discipline Number 18-10
Randomized Controlled Trial
Clinical Trial

Available Downloads

There are no available downloads for this record.
No Preview Available