Systemic inflammation, body composition, and physical performance in old community-dwellers

Area of Science:

• Gerontology and aging research
• Biomedical imaging and analysis
• Inflammation and immunology

Background:

• Aging is characterized by chronic inflammation, altered body composition, and decreased physical function.
• Understanding the interplay of these factors is crucial for healthy aging.
• Multivariate modeling offers a novel approach to characterize these complex relationships.

Purpose of the Study:

• To investigate the relationships among inflammation, body composition, and physical function in aging.
• To characterize age-related differences in these parameters using advanced statistical methods.
• To explore how these factors relate to physical performance levels in older adults.

Main Methods:

• Cross-sectional study comparing young adults (YAs) and older adults (OAs).
• Quantification of thigh skeletal muscle, subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) using MRI.
• Assessment of knee extension strength and physical performance (Short Physical Performance Battery - SPPB).
• Multi-block partial least squares-discriminant analysis (PLS-DA) to model relationships.

Main Results:

• Older adults exhibited smaller muscle volume, greater IMAT, lower muscle strength, and elevated inflammatory markers compared to young adults.
• Lower physical performance (SPPB ≤8) in older adults was associated with smaller muscle volume, greater SAT, reduced strength, and higher levels of specific cytokines (IL-1β, IL-6, IL-10, IL-12, IL-13, TNF-α, GM-CSF).
• The PLS-DA model achieved high classification accuracy (82.6% external validation) between age groups and performance levels.

Conclusions:

• Multivariate analysis revealed distinct patterns linking inflammatory profiles with functional and imaging parameters in aging.
• This approach can identify specific biomarkers and physical characteristics associated with reduced physical performance in older adults.
• Longitudinal application of this strategy could enable health status tracking, early detection of health decline, and treatment monitoring.