Frailty Assessment in an Aging Mouse Model

Area of Science:

• Gerontology and aging research
• Animal models in preclinical studies
• Translational geroscience

Background:

• Frailty index (FI) assesses biological age and health span in animal models.
• Accumulated health deficits define frailty, indicating vulnerability.
• Existing murine FI requires specialized equipment, limiting practical application.

Purpose of the Study:

• To develop and validate a streamlined, 16-item frailty index for mice.
• To enable practical, longitudinal assessment of frailty and health span in preclinical research.
• To enhance the translational relevance of animal studies in geroscience.

Main Methods:

• Adapted a 31-deficit murine FI to a 16-item version.
• Excluded deficits requiring specialized equipment or invasive testing.
• Scored deficits (0, 0.5, 1) based on severity; calculated FI as the mean score.
• Demonstrated feasibility in C57BL/6×129 mice.

Main Results:

• The 16-item FI showed age-associated increases in frailty.
• Demonstrated variation in frailty among individual mice.
• Successfully detected health deficits across multiple physiological systems.
• Validated the tool for longitudinal tracking and cohort assessment.

Conclusions:

• The streamlined 16-item FI is a practical, equipment-free tool for assessing mouse frailty and health span.
• Facilitates incorporation of frailty assessment into diverse experimental designs.
• Enhances the utility of animal models for geroscience research and translational studies.