Bone strength and composition in spacefaring rodents: systematic review and meta-analysis

Area of Science:

• Space biology
• Skeletal physiology
• Animal models in research

Background:

• Space travel poses risks to bone health.
• Animal models are crucial for studying spaceflight's effects on bone.
• Previous research has shown spaceflight impacts bone architecture and turnover.

Purpose of the Study:

• To systematically synthesize data on spaceflight's effects on bone strength and composition.
• To quantify the impact of space missions on bone mechanical properties and mineral content.
• To assess the consistency of bone health changes in rodents exposed to spaceflight.

Main Methods:

• Systematic literature search of multiple databases (Medline, Embase, Web of Science, BIOSIS, NASA Technical reports).
• Selection of 28 articles reporting bone strength and composition data from 60 rats and 60 mice across 17 space missions (7-33 days).
• Analysis of whole bone mechanical indices, bone mineral density, and calcium content.

Main Results:

• Spaceflight rodents showed significantly decreased whole bone mechanical indices, with maximum load reduced by -15.24%.
• Bone mineral density decreased by -3.13% and calcium content by -1.75% in spaceflight rodents compared to controls.
• These findings indicate significant reductions in bone strength due to spaceflight.

Conclusions:

• Spaceflight leads to substantial reductions in bone strength in rodents.
• Combined effects of altered bone architecture, mass, and tissue composition contribute to bone fragility.
• Further research is needed to understand and mitigate bone loss during space missions.