Relationship between longitudinal changes in calf circumference and skeletal muscle mass

Area of Science:

• Gerontology
• Human Physiology
• Body Composition Analysis

Background:

• Calf circumference is often used as a surrogate for skeletal muscle mass.
• Its effectiveness in tracking changes in muscle mass over time is not well-established.
• Understanding this relationship is crucial for monitoring muscle health.

Purpose of the Study:

• To investigate the longitudinal relationship between calf circumference changes and appendicular skeletal muscle mass (ASM) changes.
• To determine if age and obesity status influence this relationship.
• To validate calf circumference as an indicator of muscle mass variation.

Main Methods:

• Analysis of two-wave cohort data from 227 adults (aged 40-87 years) with a mean follow-up of 8 years.
• Measurement of calf circumference and body composition (including ASM) using dual-energy X-ray absorptiometry.
• Statistical analysis using Pearson's correlation coefficient to assess the relationship between changes.

Main Results:

• A significant positive correlation was observed between changes in calf circumference and ASM in both men and women (r=0.71).
• A 1 cm decrease in calf circumference corresponded to a 1.4 kg loss in ASM for men and 0.9 kg for women.
• Similar positive correlations were found in subgroup analyses across age and obesity categories.

Conclusions:

• Longitudinal changes in calf circumference are a reliable indicator of changes in appendicular skeletal muscle mass.
• This association remains consistent irrespective of age and obesity status.
• Calf circumference offers a practical method for monitoring skeletal muscle mass variations.