A Comparison of Two Mouse Frailty Assessment Tools

Area of Science:

• Gerontology
• Animal Models
• Biomedical Research

Background:

• Frailty is a significant concern in aging populations.
• Developing reliable tools to assess frailty in preclinical models is crucial for translational research.
• The mouse clinical frailty index (mCFI) and mouse frailty phenotype assessment (mFPA) are recent tools for evaluating frailty in mice.

Purpose of the Study:

• To compare the agreement between mCFI and mFPA in identifying frail mice.
• To investigate the association of each frailty assessment tool with age and frailty-related physiological outcomes.
• To evaluate the utility of these tools in preclinical aging studies.

Main Methods:

• Frailty was assessed in old male C57BL/6 mice (approximately 24 months) using both mCFI and mFPA.
• Physiological parameters including blood pressure, heart rate, and serum biomarkers (alanine aminotransferase, creatinine, albumin) were measured.
• Statistical analysis was performed to determine agreement between scales and correlations with outcomes.

Main Results:

• The mFPA identified no frail mice, while a modified version identified six.
• The mCFI identified 16 mice as frail, with 50.0% agreement between the two scales.
• Higher mCFI scores correlated with lower serum alanine aminotransferase, decreased heart rate, and reduced heart rate variance.

Conclusions:

• Both the mCFI and mFPA have value in assessing frailty in mice.
• The two tools do not consistently identify the same individuals as frail, similar to human frailty scales.
• Further research is needed to refine and validate these preclinical frailty assessment tools.