Cut-off values for skeletal muscle strength and physical functions in Japanese elderly with walking difficulty

Area of Science:

• Gerontology
• Nutritional Science
• Musculoskeletal Health

Background:

• Age-related decline in muscle strength and physical function is a significant concern.
• Vitamin D status is increasingly recognized for its role in maintaining skeletal muscle health.

Purpose of the Study:

• To investigate age-related changes in muscle strength and physical function.
• To examine the association between vitamin D levels and skeletal muscle function in aging adults.
• To establish cut-off values for key physical function tests to predict walking difficulties.

Main Methods:

• Cross-sectional study involving 36 men and 52 women across a wide age range.
• Assessment of skeletal muscle functions including Timed up and go (TUG) test, walking speed, handgrip strength, and Barthel Index (BI).
• Measurement of serum 25-hydroxyvitamin D [25(OH)D] levels.
• Receiver operating characteristic (ROC) analysis to determine cut-off values for predicting walking difficulties.

Main Results:

• Significant age-related decreases in skeletal muscle functions and serum 25(OH)D levels were observed in both sexes.
• Specific cut-off values were identified for TUG, walking speed, handgrip strength, and BI for males and females indicating potential walking difficulties.
• These cut-off values provide a quantifiable measure for assessing an individual's risk of mobility impairment.

Conclusions:

• Aging negatively impacts muscle strength and physical function, correlating with reduced vitamin D levels.
• The identified cut-off values are valuable tools for early detection of walking difficulties.
• Interventions focusing on vitamin D levels, rehabilitation, and nursing care can help prevent or delay handicaps and dependency.