Hibernating bears as a model for preventing disuse osteoporosis

Seth W. Donahue, Meghan Elizabeth McGee Lawrence, Kristin B. Harvey, Michael R. Vaughan, Charles T. Robbins

Research output: Contribution to journalArticle

32 Scopus citations

Abstract

The hibernating bear is an excellent model for disuse osteoporosis in humans because it is a naturally occurring large animal model. Furthermore, bears and humans have similar lower limb skeletal morphology, and bears walk plantigrade like humans. Black bears (Ursus americanus) may not develop disuse osteoporosis during long periods of disuse (i.e. hibernation) because they maintain osteoblastic bone formation during hibernation. As a consequence, bone volume, mineral content, porosity, and strength are not adversely affected by annual periods of disuse. In fact, cortical bone bending strength has been shown to increase with age in hibernating black bears without a significant change in porosity. Other animals require remobilization periods 2-3 times longer than the immobilization period to recover the bone lost during disuse. Our findings support the hypothesis that black bears, which hibernate for as long as 5-7 months annually, have evolved biological mechanisms to mitigate the adverse effects of disuse on bone porosity and strength.

Original languageEnglish (US)
Pages (from-to)1480-1488
Number of pages9
JournalJournal of Biomechanics
Volume39
Issue number8
DOIs
Publication statusPublished - Aug 28 2006
Externally publishedYes

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Keywords

  • Aging
  • Black bear
  • Bone mechanical properties
  • Bone remodeling
  • Disuse osteoporosis
  • Hibernation

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

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