Muscle Echogenicity and Changes Related to Age and Body Mass Index

Area of Science:

• Gerontology
• Biomedical Engineering
• Musculoskeletal Health

Background:

• Muscle fibers are replaced by fat and fibrous tissue with aging, decreasing muscle quality.
• Muscle quality changes are reflected in ultrasound images as increased echogenicity.
• Quantifying muscle echogenicity can assess age-related muscle degeneration.

Purpose of the Study:

• To investigate skeletal muscle quality using ultrasound echogenicity.
• To correlate muscle echogenicity with participant age and body mass index (BMI).

Main Methods:

• Cross-sectional study with 117 participants (mean age 38.9 years, BMI 28.6 kg/m²).
• Ultrasound imaging (5.0-MHz linear transducer) measured muscle thickness at four anatomical locations.
• Muscle echogenicity was analyzed using specialized grayscale image analysis software.

Main Results:

• A positive correlation was found between age and thigh-muscle echogenicity (rp = 0.534, P < .0001).
• Thigh-muscle echogenicity negatively correlated with muscle thickness (rp = -0.395, P < .0001).
• High muscle echogenicity was observed in overweight and obese participants aged 50+ (P < .05).

Conclusions:

• Older age and higher BMI are associated with increased muscle echogenicity and decreased muscle thickness.
• Ultrasound-assessed reduced muscle quality (smaller thickness) is evident in individuals with overweight, obesity, or those over 50.
• Echogenicity serves as a quantifiable marker for age- and BMI-related skeletal muscle quality decline.