Black bears with longer disuse (hibernation) periods have lower femoral osteon population density and greater mineralization and intracortical porosity

Samantha J. Wojda, David R. Weyland, Sarah K. Gray, Meghan Elizabeth McGee Lawrence, Thomas D. Drummer, Seth W. Donahue

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Intracortical bone remodeling is persistent throughout life, leading to age related increases in osteon population density (OPD). Intracortical porosity also increases with age in many mammals including humans, contributing to bone fragility and fracture risk. Unbalanced bone resorption and formation during disuse (e.g., physical inactivity) also increases intracortical porosity. In contrast, hibernating bears are a naturally occurring model for the prevention of both age-related and disuse osteoporoses. Intracortical bone remodeling is decreased during hibernation, but resorption and formation remain balanced. Black bears spend 0.25-7 months in hibernation annually depending on climate and food availability. We found longer hibernating bears demonstrate lower OPD and higher cortical bone mineralization than bears with shorter hibernation durations, but we surprisingly found longer hibernating bears had higher intracortical porosity. However, bears from three different latitudes showed age-related decreases in intracortical porosity, indicating that regardless of hibernation duration, black bears do not show the disuse- or age-related increases in intracortical porosity which is typical of other animals. This ability to prevent increases in intracortical porosity likely contributes to their ability to maintain bone strength during prolonged periods of physical inactivity and throughout life. Improving our understanding of the unique bone metabolism in hibernating bears will potentially increase our ability to develop treatments for age- and disuse-related osteoporoses in humans.

Original languageEnglish (US)
Pages (from-to)1148-1153
Number of pages6
JournalAnatomical Record
Volume296
Issue number8
DOIs
StatePublished - Aug 1 2013

Fingerprint

Haversian System
Ursidae
Hibernation
hibernation
Porosity
thighs
Population Density
Thigh
porosity
bone
mineralization
population density
Bone Remodeling
osteoporosis
bones
resorption
Osteoporosis
bone strength
Bone and Bones
Physiologic Calcification

Keywords

  • Cortical bone remodeling
  • Disuse osteoporosis
  • Hibernating bears
  • Intracortical porosity
  • Osteon population density

ASJC Scopus subject areas

  • Anatomy
  • Histology
  • Ecology, Evolution, Behavior and Systematics
  • Biotechnology

Cite this

Black bears with longer disuse (hibernation) periods have lower femoral osteon population density and greater mineralization and intracortical porosity. / Wojda, Samantha J.; Weyland, David R.; Gray, Sarah K.; McGee Lawrence, Meghan Elizabeth; Drummer, Thomas D.; Donahue, Seth W.

In: Anatomical Record, Vol. 296, No. 8, 01.08.2013, p. 1148-1153.

Research output: Contribution to journalArticle

Wojda, Samantha J. ; Weyland, David R. ; Gray, Sarah K. ; McGee Lawrence, Meghan Elizabeth ; Drummer, Thomas D. ; Donahue, Seth W. / Black bears with longer disuse (hibernation) periods have lower femoral osteon population density and greater mineralization and intracortical porosity. In: Anatomical Record. 2013 ; Vol. 296, No. 8. pp. 1148-1153.
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