Associations between inflammatory markers, body composition, and physical function: the Copenhagen Sarcopenia Study.

Area of Science:

• Gerontology
• Immunology
• Physiology

Background:

• Chronic low-grade inflammation is implicated in sarcopenia, but its role in age-related muscle loss is unclear.
• This study investigates inflammation in relation to aging and its association with body composition, strength, and physical performance in healthy Danes.

Purpose of the Study:

• To examine the relationship between age and low-grade inflammation.
• To determine the association between inflammatory biomarkers and body composition, muscle strength, and physical performance in a healthy cohort.

Main Methods:

• 1160 healthy individuals (22-93 years) were assessed for appendicular lean mass (ALM), visceral fat, handgrip strength (HGS), sit-to-stand performance, and gait speed (GS).
• Systemic levels of inflammatory markers including hsCRP, TNF-α, IL-6, IL-1β, IL-4, IL-13, and IFN-γ were measured.

Main Results:

• Appendicular lean mass, muscle strength, and physical performance decreased with age, while visceral fat increased.
• Systemic levels of hsCRP, TNF-α, IL-4, and IFN-γ increased with age; IL-1β increased in women.
• Higher hsCRP correlated with lower ALM/h², lower HGS in elderly women, and lower GS. Visceral fat was positively associated with hsCRP. Higher TNF-α and hsCRP were found in those with low HGS.

Conclusions:

• Systemic inflammation markers (hsCRP, TNF-α) increase with age and are associated with poorer physical function, particularly in frail elderly.
• High hsCRP showed weak associations with low muscle mass but was linked to increased visceral fat and reduced physical function.
• Chronic low-grade inflammation may not be the primary driver of age-related muscle mass loss as previously suggested.