Evaluating the relationship between muscle and bone modeling response in older adults

Area of Science:

• Bone biology and biomechanics
• Gerontology and aging research
• Skeletal health and fragility

Background:

• Bone modeling adapts bone strength to muscle loading throughout life.
• Age-related bone fragility may be linked to diminished bone modeling.
• Femoral stress, estimated via engineering models, reflects bone's response to load.

Purpose of the Study:

• To evaluate associations between lean mass, muscle strength, and femoral stress.
• To determine how much lean mass and muscle strength explain femoral stress variation.
• To investigate these relationships in healthy older adults.

Main Methods:

• Utilized data from 2539 healthy older adults in the Health ABC study.
• Employed an engineering model using DXA-derived bone geometry and loading information to estimate femoral stress.
• Applied linear regression to assess associations of lean mass and knee strength with femoral stress, adjusting for confounders and BMI.

Main Results:

• Mean femoral stress was higher in women than in men.
• Percent lean mass explained more variation in femoral stress than knee strength in both sexes.
• Increased lean mass was significantly associated with lower mean femoral stress in both men and women.

Conclusions:

• Lean mass is a significant factor in bone modeling response, as indicated by femoral stress.
• Findings provide insight into sex-based differences in bone modeling and response to load.
• Higher lean mass may contribute to maintaining bone strength and reducing fragility in older adults.